diff --git a/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.sgml b/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.sgml index 51aaa388e4..465d4c05a7 100644 --- a/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.sgml @@ -1,6747 +1,6747 @@ Advanced Networking Synopsis This chapter will cover some of the more frequently used network services on Unix systems. We will cover how to define, setup, test and maintain all of the network services that FreeBSD utilizes. In addition, there have been example configuration files included throughout this chapter for you to benefit from. After reading this chapter, you will know: The basics of gateways and routes. How to make FreeBSD act as a bridge. How to setup a network filesystem. How to setup network booting on a diskless machine. How to setup a network information server for sharing user accounts. How to setup automatic network settings using DHCP. How to setup a domain name server. How to synchronize the time and date, and setup a time server, with the NTP protocol. How to setup network address translation. How to manage the inetd daemon. How to connect two computers via PLIP. How to setup IPv6 on a FreeBSD machine. Before reading this chapter, you should: Understand the basics of the /etc/rc scripts. Be familiar with basic network terminology. Coranth Gryphon Contributed by Gateways and Routes routing gateway subnet For one machine to be able to find another over a network, there must be a mechanism in place to describe how to get from one to the other. This is called routing. A route is a defined pair of addresses: a destination and a gateway. The pair indicates that if you are trying to get to this destination, communicate through this gateway. There are three types of destinations: individual hosts, subnets, and default. The default route is used if none of the other routes apply. We will talk a little bit more about default routes later on. There are also three types of gateways: individual hosts, interfaces (also called links), and Ethernet hardware addresses (MAC addresses). An Example To illustrate different aspects of routing, we will use the following example from netstat: &prompt.user; netstat -r Routing tables Destination Gateway Flags Refs Use Netif Expire default outside-gw UGSc 37 418 ppp0 localhost localhost UH 0 181 lo0 test0 0:e0:b5:36:cf:4f UHLW 5 63288 ed0 77 10.20.30.255 link#1 UHLW 1 2421 example.com link#1 UC 0 0 host1 0:e0:a8:37:8:1e UHLW 3 4601 lo0 host2 0:e0:a8:37:8:1e UHLW 0 5 lo0 => host2.example.com link#1 UC 0 0 224 link#1 UC 0 0 default route The first two lines specify the default route (which we will cover in the next section) and the localhost route. loopback device The interface (Netif column) that this routing table specifies to use for localhost is lo0, also known as the loopback device. This says to keep all traffic for this destination internal, rather than sending it out over the LAN, since it will only end up back where it started. Ethernet MAC address The next thing that stands out are the addresses beginning with 0:e0:. These are Ethernet hardware addresses, which are also known as MAC addresses. FreeBSD will automatically identify any hosts (test0 in the example) on the local Ethernet and add a route for that host, directly to it over the Ethernet interface, ed0. There is also a timeout (Expire column) associated with this type of route, which is used if we fail to hear from the host in a specific amount of time. When this happens, the route to this host will be automatically deleted. These hosts are identified using a mechanism known as RIP (Routing Information Protocol), which figures out routes to local hosts based upon a shortest path determination. subnet FreeBSD will also add subnet routes for the local subnet (10.20.30.255 is the broadcast address for the subnet 10.20.30, and example.com is the domain name associated with that subnet). The designation link#1 refers to the first Ethernet card in the machine. You will notice no additional interface is specified for those. Both of these groups (local network hosts and local subnets) have their routes automatically configured by a daemon called routed. If this is not run, then only routes which are statically defined (i.e. entered explicitly) will exist. The host1 line refers to our host, which it knows by Ethernet address. Since we are the sending host, FreeBSD knows to use the loopback interface (lo0) rather than sending it out over the Ethernet interface. The two host2 lines are an example of what happens when we use an &man.ifconfig.8; alias (see the section on Ethernet for reasons why we would do this). The => symbol after the lo0 interface says that not only are we using the loopback (since this address also refers to the local host), but specifically it is an alias. Such routes only show up on the host that supports the alias; all other hosts on the local network will simply have a link#1 line for such routes. The final line (destination subnet 224) deals with multicasting, which will be covered in another section. Finally, various attributes of each route can be seen in the Flags column. Below is a short table of some of these flags and their meanings: U Up: The route is active. H Host: The route destination is a single host. G Gateway: Send anything for this destination on to this remote system, which will figure out from there where to send it. S Static: This route was configured manually, not automatically generated by the system. C Clone: Generates a new route based upon this route for machines we connect to. This type of route is normally used for local networks. W WasCloned: Indicated a route that was auto-configured based upon a local area network (Clone) route. L Link: Route involves references to Ethernet hardware. Default Routes default route When the local system needs to make a connection to a remote host, it checks the routing table to determine if a known path exists. If the remote host falls into a subnet that we know how to reach (Cloned routes), then the system checks to see if it can connect along that interface. If all known paths fail, the system has one last option: the default route. This route is a special type of gateway route (usually the only one present in the system), and is always marked with a c in the flags field. For hosts on a local area network, this gateway is set to whatever machine has a direct connection to the outside world (whether via PPP link, DSL, cable modem, T1, or another network interface). If you are configuring the default route for a machine which itself is functioning as the gateway to the outside world, then the default route will be the gateway machine at your Internet Service Provider's (ISP) site. Let us look at an example of default routes. This is a common configuration: [Local2] <--ether--> [Local1] <--PPP--> [ISP-Serv] <--ether--> [T1-GW] The hosts Local1 and Local2 are at your site. Local1 is connected to an ISP via a dial up PPP connection. This PPP server computer is connected through a local area network to another gateway computer through an external interface to the ISPs Internet feed. The default routes for each of your machines will be: Host Default Gateway Interface Local2 Local1 Ethernet Local1 T1-GW PPP A common question is Why (or how) would we set the T1-GW to be the default gateway for Local1, rather than the ISP server it is connected to?. Remember, since the PPP interface is using an address on the ISP's local network for your side of the connection, routes for any other machines on the ISP's local network will be automatically generated. Hence, you will already know how to reach the T1-GW machine, so there is no need for the intermediate step of sending traffic to the ISP server. As a final note, it is common to use the address X.X.X.1 as the gateway address for your local network. So (using the same example), if your local class-C address space was 10.20.30 and your ISP was using 10.9.9 then the default routes would be: Host Default Route Local2 (10.20.30.2) Local1 (10.20.30.1) Local1 (10.20.30.1, 10.9.9.30) T1-GW (10.9.9.1) Dual Homed Hosts dual homed hosts There is one other type of configuration that we should cover, and that is a host that sits on two different networks. Technically, any machine functioning as a gateway (in the example above, using a PPP connection) counts as a dual-homed host. But the term is really only used to refer to a machine that sits on two local-area networks. In one case, the machine has two Ethernet cards, each having an address on the separate subnets. Alternately, the machine may only have one Ethernet card, and be using &man.ifconfig.8; aliasing. The former is used if two physically separate Ethernet networks are in use, the latter if there is one physical network segment, but two logically separate subnets. Either way, routing tables are set up so that each subnet knows that this machine is the defined gateway (inbound route) to the other subnet. This configuration, with the machine acting as a router between the two subnets, is often used when we need to implement packet filtering or firewall security in either or both directions. If you want this machine to actually forward packets between the two interfaces, you need to tell FreeBSD to enable this ability. Building a Router router A network router is simply a system that forwards packets from one interface to another. Internet standards and good engineering practice prevent the FreeBSD Project from enabling this by default in FreeBSD. You can enable this feature by changing the following variable to YES in &man.rc.conf.5;: gateway_enable=YES # Set to YES if this host will be a gateway This option will set the &man.sysctl.8; variable net.inet.ip.forwarding to 1. If you should need to stop routing temporarily, you can reset this to 0 temporarily. Your new router will need routes to know where to send the traffic. If your network is simple enough you can use static routes. FreeBSD also comes with the standard BSD routing daemon &man.routed.8;, which speaks RIP (both version 1 and version 2) and IRDP. Support for BGP v4, OSPF v2, and other sophisticated routing protocols is available with the net/zebra package. Commercial products such as gated are also available for more complex network routing solutions. BGP RIP OSPF Even when FreeBSD is configured in this way, it does not completely comply with the Internet standard requirements for routers. It comes close enough for ordinary use, however. Routing Propagation routing propagation We have already talked about how we define our routes to the outside world, but not about how the outside world finds us. We already know that routing tables can be set up so that all traffic for a particular address space (in our examples, a class-C subnet) can be sent to a particular host on that network, which will forward the packets inbound. When you get an address space assigned to your site, your service provider will set up their routing tables so that all traffic for your subnet will be sent down your PPP link to your site. But how do sites across the country know to send to your ISP? There is a system (much like the distributed DNS information) that keeps track of all assigned address-spaces, and defines their point of connection to the Internet Backbone. The Backbone are the main trunk lines that carry Internet traffic across the country, and around the world. Each backbone machine has a copy of a master set of tables, which direct traffic for a particular network to a specific backbone carrier, and from there down the chain of service providers until it reaches your network. It is the task of your service provider to advertise to the backbone sites that they are the point of connection (and thus the path inward) for your site. This is known as route propagation. Troubleshooting traceroute Sometimes, there is a problem with routing propagation, and some sites are unable to connect to you. Perhaps the most useful command for trying to figure out where routing is breaking down is the &man.traceroute.8; command. It is equally useful if you cannot seem to make a connection to a remote machine (i.e. &man.ping.8; fails). The &man.traceroute.8; command is run with the name of the remote host you are trying to connect to. It will show the gateway hosts along the path of the attempt, eventually either reaching the target host, or terminating because of a lack of connection. For more information, see the manual page for &man.traceroute.8;. Eric Anderson Written by Wireless Networking wireless networking 802.11 wireless networking Introduction It can be very useful to be able to use a computer without the annoyance of having a network cable attached at all times. FreeBSD can be used as a wireless client, and even as a wireless access point. Wireless Modes of Operation There are two different ways to configure 802.11 wireless devices: BSS and IBSS. BSS mode BSS mode is the mode that typically is used. BSS mode is also called infrastructure mode. In this mode, a number of wireless access points are connected to a wired network. Each wireless network has its own name. This name is called the SSID of the network. Wireless clients connect to these wireless access points. The IEEE 802.11 standard defines the protocol that wireless networks use to connect. A wireless client can be tied to a specific network, when a SSID is set. A wireless client can also attach to any network by not explicitly setting a SSID. IBSS Mode IBSS mode, also called ad-hoc mode, is designed for point to point connections. There are actually two types of ad-hoc mode. One is IBSS mode, also called ad-hoc or IEEE ad-hoc mode. This mode is defined by the IEEE 802.11 standards. The second is called demo ad-hoc mode or Lucent ad-hoc mode (and sometimes, confusingly, ad-hoc mode). This is the old, pre-802.11 ad-hoc mode and should only be used for legacy installations. We will not cover either of the ad-hoc modes further. Infrastructure mode Access Points Access points are wireless networking devices that allow one or more wireless clients to use the device as a central hub. When using an access point, all clients communicate through the access point. Multiple access points are often used to cover a complete area such as a house, business, or park with a wireless network. Access points typically have multiple network connections: the wireless card, and one or more wired Ethernet adapters for connection to the rest of the network. Access points can either be purchased prebuilt, or you can build your own with FreeBSD and a supported wireless card. Several vendors make wireless access points and wireless cards with various features. Building a FreeBSD Access Point wireless networking access point Requirements In order to set up a wireless access point with FreeBSD, you need to have a compatible wireless card. Currently, only cards with the Prism chipset are supported. You will also need a wired network card that is supported by FreeBSD (this should not be difficult to find, FreeBSD supports a lot of different devices). For this guide, we will assume you want to &man.bridge.4; all traffic between the wireless device and the network attached to the wired network card. The hostap functionality that FreeBSD uses to implement the access point works best with certain versions of firmware. Prism 2 cards should use firmware version 1.3.4 or newer. Prism 2.5 and Prism 3 cards should use firmware 1.4.9. Older versions of the firmware way or may not function correctly. At this time, the only way to update cards is with windows firmware update utilities available from your card's manufacturer. Setting it up First, make sure your system can see the wireless card: &prompt.root; ifconfig -a wi0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 inet6 fe80::202:2dff:fe2d:c938%wi0 prefixlen 64 scopeid 0x7 inet 0.0.0.0 netmask 0xff000000 broadcast 255.255.255.255 ether 00:09:2d:2d:c9:50 media: IEEE 802.11 Wireless Ethernet autoselect (DS/2Mbps) status: no carrier ssid "" stationname "FreeBSD Wireless node" channel 10 authmode OPEN powersavemode OFF powersavesleep 100 wepmode OFF weptxkey 1 Do not worry about the details now, just make sure it shows you something to indicate you have a wireless card installed. Next, you will need to load a module in order to get the bridging part of FreeBSD ready for the access point. In order to load the &man.bridge.4; module, simply run the following command: &prompt.root; kldload bridge It should not have produced any errors when loading the module. If it did, you may need to compile the &man.bridge.4; code into your kernel. The Bridging section of the handbook should be able to help you accomplish that task. Now that you have the bridging stuff done, we need to tell the FreeBSD kernel which interfaces to bridge together. We do that by using &man.sysctl.8;: &prompt.root; sysctl net.link.ether.bridge=1 &prompt.root; sysctl net.link.ether.bridge_cfg="wi0 xl0" &prompt.root; sysctl net.inet.ip.forwarding=1 Now it is time for the wireless card setup. The following command will set the card into an access point: &prompt.root; ifconfig wi0 ssid my_net channel 11 media DS/11Mbps mediaopt hostap up stationname "FreeBSD AP" The &man.ifconfig.8; line brings the wi0 interface up, sets its SSID to my_net, and sets the station name to FreeBSD AP. The sets the card into 11Mbps mode and is needed for any to take effect. The option places the interface into access point mode. The option sets the 802.11b channel to use. The &man.wicontrol.8; man page has valid channel options for your regulatory domain. Now you should have a complete functioning access point up and running. You are encouraged to read &man.wicontrol.8;, &man.ifconfig.8;, and &man.wi.4; for further information. It is also suggested that you read the section on encryption that follows. Status information Once the access point is configured and operational, operators will want to see the clients that are associated with the access point. At any time, the operator may type: &prompt.root; wicontrol -l 1 station: 00:09:b7:7b:9d:16 asid=04c0, flags=3<ASSOC,AUTH>, caps=1<ESS>, rates=f<1M,2M,5.5M,11M>, sig=38/15 This shows that there's one station associated, along with its parameters. The signal indicated should be used as a relative indication of strength only. Its translation to dBm or other units varies between different firmware revisions. Clients A wireless client is a system that accesses an access point or another client directly. Typically, wireless clients only have one network device, the wireless networking card. There are a few different ways to configure a wireless client. These are based on the different wireless modes, generally BSS (infrastructure mode, which requires an access point), and IBSS (ad-hoc, or peer-to-peer mode). In our example, we will use the most popular of the two, BSS mode, to talk to an access point. Requirements There is only one real requirement for setting up FreeBSD as a wireless client. You will need a wireless card that is supported by FreeBSD. Setting Up A Wireless FreeBSD Client You will need to know a few things about the wireless network you are joining before you start. In this example, we are joining a network that has a name of my_net, and encryption turned off. Note: In this example, we are not using encryption, which is a dangerous situation. In the next section, you will learn how to turn on encryption, and why it is important to do so, and why some encryption technologies still do not completely protect you. Make sure your card is recognized by FreeBSD: &prompt.root; ifconfig -a wi0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 inet6 fe80::202:2dff:fe2d:c938%wi0 prefixlen 64 scopeid 0x7 inet 0.0.0.0 netmask 0xff000000 broadcast 255.255.255.255 ether 00:09:2d:2d:c9:50 media: IEEE 802.11 Wireless Ethernet autoselect (DS/2Mbps) status: no carrier ssid "" stationname "FreeBSD Wireless node" channel 10 authmode OPEN powersavemode OFF powersavesleep 100 wepmode OFF weptxkey 1 Now, we will set the card to the correct settings for our network: &prompt.root; ifconfig wi0 inet 192.168.0.20 netmask 255.255.255.0 ssid my_net Replace 192.168.0.20 and 255.255.255.0 with a valid IP address and netmask on your wired network. Remember, our access point is bridging the data between the wireless network, and the wired network, so it will appear to the other devices on your network that you are on the wired network just as they are. Once you have done that, you should be able to ping hosts on the wired network just as if you were connected using a standard wired connection. If you are experiencing problems with your wireless connection, check to make sure that your are associated (connected) to the access point: &prompt.root; ifconfig wi0 should return some information, and you should see: status: associated If it does not show associated, then you may be out of range of the access point, do not have encryption on, or possibly have a configuration problem. Encryption wireless networking encryption Encryption on a wireless network is important because you no longer have the ability to keep the network contained in a well protected area. Your wireless data will be broadcast across your entire neighborhood, so anyone who cares to read it can. This is where encryption comes in. By encrypting the data that is sent over the airwaves, you make it much more difficult for any interested party to grab your data right out of the air. The two most common ways to encrypt the data between your client and the access point, are WEP, and &man.ipsec.4;. WEP WEP WEP is an abbreviation for Wired Equivalency Protocol. WEP is an attempt to make wireless networks as safe and secure as a wired network. Unfortunately, it has been cracked, and is fairly trivial to break. This also means it is not something to rely on when it comes to encrypting sensitive data. It is better than nothing, so use the following to turn on WEP on your new FreeBSD access point: &prompt.root; ifconfig wi0 inet up ssid my_net wepmode on wepkey 0x1234567890 media DS/11Mbps mediaopt hostap And you can turn on WEP on a client with this command: &prompt.root; ifconfig wi0 inet 192.168.0.20 netmask 255.255.255.0 ssid my_net wepmode on wepkey 0x1234567890 Note that you should replace the 0x1234567890 with a more unique key. IPsec &man.ipsec.4; is a much more robust and powerful tool for encrypting data across a network. This is definitely the preferred way to encrypt wireless data over a network. You can read more about &man.ipsec.4; security and how to implement it in the IPsec section of the handbook. Tools There are a small number of tools available for use in debugging and setting up your wireless network, and here we will attempt to describe some of them and what they do. <application>bsd-airtools</application> The bsd-airtools package is a complete toolset that includes wireless auditing tools for WEP key cracking, access point detection, etc. The bsd-airtools utilities can be installed from the net/bsd-airtools port. Information on installing ports can be found in of the handbook. The program dstumbler is the packaged tool that allows for access point discovery and signal to noise ratio graphing. If you are having a hard time getting your access point up and running, dstumbler may help you get started. To test your wireless network security, you may choose to use dweputils (dwepcrack, dwepdump and dwepkeygen) to help you determine if WEP is the right solution to your wireless security needs. wicontrol, ancontrol, raycontrol These are the tools you use to control how your wireless card behaves on the wireless network. In the examples above, we have chosen to use &man.wicontrol.8;, since our wireless card is a wi0 interface. If you had a Cisco wireless device, it would come up as an0, and therefore you would use &man.ancontrol.8;. ifconfig ifconfig &man.ifconfig.8; can be used to do many of the same options as &man.wicontrol.8;, however it does lack a few options. Check &man.ifconfig.8; for command line parameters and options. Supported Cards Access Points The only cards that are currently supported for BSS (as an access point) mode are devices based on the Prism 2, 2.5, or 3 chipsets. For a complete list, look at &man.wi.4;. Clients Almost all 802.11b wireless cards are currently supported under FreeBSD. Most cards based on Prism, Spectrum24, Hermes, Aironet, and Raylink will work as a wireless network card in IBSS (ad-hoc, peer-to-peer, and BSS) mode. Steve Peterson Written by Bridging Introduction IP subnet bridge It is sometimes useful to divide one physical network (such as an Ethernet segment) into two separate network segments without having to create IP subnets and use a router to connect the segments together. A device that connects two networks together in this fashion is called a bridge. A FreeBSD system with two network interface cards can act as a bridge. The bridge works by learning the MAC layer addresses (Ethernet addresses) of the devices on each of its network interfaces. It forwards traffic between two networks only when its source and destination are on different networks. In many respects, a bridge is like an Ethernet switch with very few ports. Situations Where Bridging Is Appropriate There are two common situations in which a bridge is used today. High Traffic on a Segment Situation one is where your physical network segment is overloaded with traffic, but you do not want for whatever reason to subnet the network and interconnect the subnets with a router. Let us consider an example of a newspaper where the Editorial and Production departments are on the same subnetwork. The Editorial users all use server A for file service, and the Production users are on server B. An Ethernet is used to connect all users together, and high loads on the network are slowing things down. If the Editorial users could be segregated on one network segment and the Production users on another, the two network segments could be connected with a bridge. Only the network traffic destined for interfaces on the other side of the bridge would be sent to the other network, reducing congestion on each network segment. Filtering/Traffic Shaping Firewall firewall IP Masquerading The second common situation is where firewall functionality is needed without IP Masquerading (NAT). An example is a small company that is connected via DSL or ISDN to their ISP. They have a 13 globally-accessible IP addresses from their ISP and have 10 PCs on their network. In this situation, using a router-based firewall is difficult because of subnetting issues. router DSL ISDN A bridge-based firewall can be configured and dropped into the path just downstream of their DSL/ISDN router without any IP numbering issues. Configuring a Bridge Network Interface Card Selection A bridge requires at least two network cards to function. Unfortunately, not all network interface cards as of FreeBSD 4.0 support bridging. Read &man.bridge.4; for details on the cards that are supported. Install and test the two network cards before continuing. Kernel Configuration Changes kernel options options BRIDGE To enable kernel support for bridging, add the: options BRIDGE statement to your kernel configuration file, and rebuild your kernel. Firewall Support firewall If you are planning to use the bridge as a firewall, you will need to add the IPFIREWALL option as well. Read for general information on configuring the bridge as a firewall. If you need to allow non-IP packets (such as ARP) to flow through the bridge, there is an undocumented firewall option that must be set. This option is IPFIREWALL_DEFAULT_TO_ACCEPT. Note that this changes the default rule for the firewall to accept any packet. Make sure you know how this changes the meaning of your ruleset before you set it. Traffic Shaping Support If you want to use the bridge as a traffic shaper, you will need to add the DUMMYNET option to your kernel configuration. Read &man.dummynet.4; for further information. Enabling the Bridge Add the line: net.link.ether.bridge=1 to /etc/sysctl.conf to enable the bridge at runtime, and the line: net.link.ether.bridge_cfg=if1,if2 to enable bridging on the specified interfaces (replace if1 and if2 with the names of your two network interfaces). If you want the bridged packets to be filtered by &man.ipfw.8;, you should add: net.link.ether.bridge_ipfw=1 as well. Other Information If you want to be able to telnet into the bridge from the network, it is OK to assign one of the network cards an IP address. The consensus is that assigning both cards an address is a bad idea. If you have multiple bridges on your network, there cannot be more than one path between any two workstations. Technically, this means that there is no support for spanning tree link management. A bridge can add latency to your ping times, especially for traffic from one segment to another. Tom Rhodes Reorganized and enhanced by Bill Swingle Written by NFS NFS Among the many different filesystems that FreeBSD supports is the Network File System, also known as NFS. NFS allows a system to share directories and files with others over a network. By using NFS, users and programs can access files on remote systems almost as if they were local files. Some of the most notable benefits that NFS can provide are: Local workstations use less disk space because commonly used data can be stored on a single machine and still remain accessible to others over the network. There is no need for users to have separate home directories on every network machine. Home directories could be setup on the NFS server and made available throughout the network. Storage devices such as floppy disks, CDROM drives, and ZIP drives can be used by other machines on the network. This may reduce the number of removable media drives throughout the network. How <acronym>NFS</acronym> Works NFS consists of at least two main parts: a server and one or more clients. The client remotely accesses the data that is stored on the server machine. In order for this to function properly a few processes have to be configured and running: The server has to be running the following daemons: NFS server portmap mountd nfsd Daemon Description nfsd The NFS daemon which services requests from the NFS clients. mountd The NFS mount daemon which carries out the requests that &man.nfsd.8; passes on to it. portmap The portmapper daemon allows NFS clients to discover which port the NFS server is using. The client can also run a daemon, known as nfsiod. The nfsiod daemon services the requests from the NFS server. This is optional, and improves performance, but is not required for normal and correct operation. See the &man.nfsiod.8; manual page for more information. Configuring <acronym>NFS</acronym> NFS configuration NFS configuration is a relatively straightforward process. The processes that need to be running can all start at boot time with a few modifications to your /etc/rc.conf file. On the NFS server, make sure that the following options are configured in the /etc/rc.conf file: portmap_enable="YES" nfs_server_enable="YES" mountd_flags="-r" mountd runs automatically whenever the NFS server is enabled. On the client, make sure this option is present in /etc/rc.conf: nfs_client_enable="YES" The /etc/exports file specifies which filesystems NFS should export (sometimes referred to as share). Each line in /etc/exports specifies a filesystem to be exported and which machines have access to that filesystem. Along with what machines have access to that filesystem, access options may also be specified. There are many such options that can be used in this file but only a few will be mentioned here. You can easily discover other options by reading over the &man.exports.5; manual page. Here are a few example /etc/exports entries: NFS export examples The following examples give an idea of how to export filesystems, although the settings may be different depending on your environment and network configuration. For instance, to export the /cdrom directory to three example machines that have the same domain name as the server (hence the lack of a domain name for each) or have entries in your /etc/hosts file. The flag makes the exported filesystem read-only. With this flag, the remote system will not be able to write any changes to the exported filesystem. /cdrom -ro host1 host2 host3 The following line exports /home to three hosts by IP address. This is a useful setup if you have a private network without a DNS server configured. Optionally the /etc/hosts file could be configured for internal hostnames; please review &man.hosts.5; for more information. The flag allows the subdirectories to be mount points. In other words, it will not mount the subdirectories but permit the client to mount only the directories that are required or needed. /home -alldirs 10.0.0.2 10.0.0.3 10.0.0.4 The following line exports /a so that two clients from different domains may access the filesystem. The flag allows the root user on the remote system to write data on the exported filesystem as root. If the -maproot=root flag is not specified, then even if a user has root access on the remote system, they will not be able to modify files on the exported filesystem. /a -maproot=root host.example.com box.example.org In order for a client to access an exported filesystem, the client must have permission to do so. Make sure the client is listed in your /etc/exports file. In /etc/exports, each line represents the export information for one filesystem to one host. A remote host can only be specified once per filesystem, and may only have one default entry. For example, assume that /usr is a single filesystem. The following /etc/exports would be invalid: /usr/src client /usr/ports client One filesystem, /usr, has two lines specifying exports to the same host, client. The correct format for this situation is: /usr/src /usr/ports client The properties of one filesystem exported to a given host must all occur on one line. Lines without a client specified are treated as a single host. This limits how you can export filesystems, but for most people this is not an issue. The following is an example of a valid export list, where /usr and /exports are local filesystems: # Export src and ports to client01 and client02, but only # client01 has root privileges on it /usr/src /usr/ports -maproot=root client01 /usr/src /usr/ports client02 # The client machines have root and can mount anywhere # on /exports. Anyone in the world can mount /exports/obj read-only /exports -alldirs -maproot=root client01 client02 /exports/obj -ro You must restart mountd whenever you modify /etc/exports so the changes can take effect. This can be accomplished by sending the HUP signal to the mountd process: &prompt.root; kill -HUP `cat /var/run/mountd.pid` Alternatively, a reboot will make FreeBSD set everything up properly. A reboot is not necessary though. Executing the following commands as root should start everything up. On the NFS server: &prompt.root; portmap &prompt.root; nfsd -u -t -n 4 &prompt.root; mountd -r On the NFS client: &prompt.root; nfsiod -n 4 Now everything should be ready to actually mount a remote file system. In these examples the server's name will be server and the client's name will be client. If you only want to temporarily mount a remote filesystem or would rather test the configuration, just execute a command like this as root on the client: NFS mounting &prompt.root; mount server:/home /mnt This will mount the /home directory on the server at /mnt on the client. If everything is set up correctly you should be able to enter /mnt on the client and see all the files that are on the server. If you want to automatically mount a remote filesystem each time the computer boots, add the filesystem to the /etc/fstab file. Here is an example: server:/home /mnt nfs rw 0 0 The &man.fstab.5; manual page lists all the available options. Practical Uses NFS has many practical uses. Some of the more common ones are listed below: NFS uses Set several machines to share a CDROM or other media among them. This is cheaper and often a more convenient method to install software on multiple machines. On large networks, it might be more convenient to configure a central NFS server in which to store all the user home directories. These home directories can then be exported to the network so that users would always have the same home directory, regardless of which workstation they log in to. Several machines could have a common /usr/ports/distfiles directory. That way, when you need to install a port on several machines, you can quickly access the source without downloading it on each machine. Wylie Stilwell Contributed by Chern Lee Rewritten by amd amd automatic mounter daemon &man.amd.8; (the automatic mounter daemon) automatically mounts a remote filesystem whenever a file or directory within that filesystem is accessed. Filesystems that are inactive for a period of time will also be automatically unmounted by amd. Using amd provides a simple alternative to permanent mounts, as permanent mounts are usually listed in /etc/fstab. amd operates by attaching itself as an NFS server to the /host and /net directories. When a file is accessed within one of these directories, amd looks up the corresponding remote mount and automatically mounts it. /net is used to mount an exported filesystem from an IP address, while /host is used to mount an export from a remote hostname. An access to a file within /host/foobar/usr would tell amd to attempt to mount the /usr export on the host foobar. Mounting an Export with <application>amd</application> You can view the available mounts of a remote host with the showmount command. For example, to view the mounts of a host named foobar, you can use: &prompt.user; showmount -e foobar Exports list on foobar: /usr 10.10.10.0 /a 10.10.10.0 &prompt.user; cd /host/foobar/usr As seen in the example, the showmount shows /usr as an export. When changing directories to /host/foobar/usr, amd attempts to resolve the hostname foobar and automatically mount the desired export. amd can be started by the startup scripts by placing the following lines in /etc/rc.conf: amd_enable="YES" Additionally, custom flags can be passed to amd from the amd_flags option. By default, amd_flags is set to: amd_flags="-a /.amd_mnt -l syslog /host /etc/amd.map /net /etc/amd.map" The /etc/amd.map file defines the default options that exports are mounted with. The /etc/amd.conf file defines some of the more advanced features of amd. Consult the &man.amd.8; and &man.amd.conf.5; manual pages for more information. John Lind Contributed by Problems Integrating with Other Systems Certain Ethernet adapters for ISA PC systems have limitations which can lead to serious network problems, particularly with NFS. This difficulty is not specific to FreeBSD, but FreeBSD systems are affected by it. The problem nearly always occurs when (FreeBSD) PC systems are networked with high-performance workstations, such as those made by Silicon Graphics, Inc., and Sun Microsystems, Inc. The NFS mount will work fine, and some operations may succeed, but suddenly the server will seem to become unresponsive to the client, even though requests to and from other systems continue to be processed. This happens to the client system, whether the client is the FreeBSD system or the workstation. On many systems, there is no way to shut down the client gracefully once this problem has manifested itself. The only solution is often to reset the client, because the NFS situation cannot be resolved. Though the correct solution is to get a higher performance and capacity Ethernet adapter for the FreeBSD system, there is a simple workaround that will allow satisfactory operation. If the FreeBSD system is the server, include the option on the mount from the client. If the FreeBSD system is the client, then mount the NFS filesystem with the option . These options may be specified using the fourth field of the fstab entry on the client for automatic mounts, or by using the parameter of the mount command for manual mounts. It should be noted that there is a different problem, sometimes mistaken for this one, when the NFS servers and clients are on different networks. If that is the case, make certain that your routers are routing the necessary UDP information, or you will not get anywhere, no matter what else you are doing. In the following examples, fastws is the host (interface) name of a high-performance workstation, and freebox is the host (interface) name of a FreeBSD system with a lower-performance Ethernet adapter. Also, /sharedfs will be the exported NFS filesystem (see &man.exports.5;), and /project will be the mount point on the client for the exported filesystem. In all cases, note that additional options, such as or and may be desirable in your application. Examples for the FreeBSD system (freebox) as the client in /etc/fstab on freebox: fastws:/sharedfs /project nfs rw,-r=1024 0 0 As a manual mount command on freebox: &prompt.root; mount -t nfs -o -r=1024 fastws:/sharedfs /project Examples for the FreeBSD system as the server in /etc/fstab on fastws: freebox:/sharedfs /project nfs rw,-w=1024 0 0 As a manual mount command on fastws: &prompt.root; mount -t nfs -o -w=1024 freebox:/sharedfs /project Nearly any 16-bit Ethernet adapter will allow operation without the above restrictions on the read or write size. For anyone who cares, here is what happens when the failure occurs, which also explains why it is unrecoverable. NFS typically works with a block size of 8 k (though it may do fragments of smaller sizes). Since the maximum Ethernet packet is around 1500 bytes, the NFS block gets split into multiple Ethernet packets, even though it is still a single unit to the upper-level code, and must be received, assembled, and acknowledged as a unit. The high-performance workstations can pump out the packets which comprise the NFS unit one right after the other, just as close together as the standard allows. On the smaller, lower capacity cards, the later packets overrun the earlier packets of the same unit before they can be transferred to the host and the unit as a whole cannot be reconstructed or acknowledged. As a result, the workstation will time out and try again, but it will try again with the entire 8 K unit, and the process will be repeated, ad infinitum. By keeping the unit size below the Ethernet packet size limitation, we ensure that any complete Ethernet packet received can be acknowledged individually, avoiding the deadlock situation. Overruns may still occur when a high-performance workstations is slamming data out to a PC system, but with the better cards, such overruns are not guaranteed on NFS units. When an overrun occurs, the units affected will be retransmitted, and there will be a fair chance that they will be received, assembled, and acknowledged. Jean-François Dockès Updated by Diskless Operation diskless workstation diskless operation A FreeBSD machine can boot over the network and operate without a local disk, using filesystems mounted from an NFS server. No system modification is necessary, beyond standard configuration files. Such a system is easy to set up because all the necessary elements are readily available: There are at least two possible methods to load the kernel over the network: PXE: Intel's Preboot Execution Environment system is a form of smart boot ROM built into some networking cards or motherboards. See &man.pxeboot.8; for more details. The etherboot port (net/etherboot) produces ROM-able code to boot kernels over the network. The code can be either burnt into a boot PROM on a network card, or loaded from a local floppy (or hard) disk drive, or from a running MS-DOS system. Many network cards are supported. A sample script (/usr/share/examples/diskless/clone_root) eases the creation and maintenance of the workstation's root filesystem on the server. The script will probably require a little customization but it will get you started very quickly. Standard system startup files exist in /etc to detect and support a diskless system startup. Swapping, if needed, can be done either to an NFS file or to a local disk. There are many ways to set up diskless workstations. Many elements are involved, and most can be customized to suit local taste. The following will describe the setup of a complete system, emphasizing simplicity and compatibility with the standard FreeBSD startup scripts. The system described has the following characteristics: The diskless workstations use a shared read-only root filesystem, and a shared read-only /usr. The root filesystem is a copy of a standard FreeBSD root (typically the server's), with some configuration files overridden by ones specific to diskless operation or, possibly, to the workstation they belong to. The parts of the root which have to be writable are overlaid with &man.mfs.8; filesystems. Any changes will be lost when the system reboots. The kernel is loaded by etherboot , using DHCP (or BOOTP) and TFTP. As described, this system is insecure. It should live in a protected area of a network, and be untrusted by other hosts. Setup Instructions Configuring DHCP/BOOTP diskless operation booting There are two protocols that are commonly used to boot a workstation that retrieves its configuration over the network: BOOTP and DHCP. They are used at several points in the workstation bootstrap: etherboot uses DHCP (by default) or BOOTP (needs a configuration option) to find the kernel. (PXE uses DHCP). The kernel uses BOOTP to locate the NFS root. It is possible to configure a system to use only BOOTP. The &man.bootpd.8; server program is included in the base FreeBSD system. However, DHCP has a number of advantages over BOOTP (nicer configuration files, possibility of using PXE, plus many others not directly related to diskless operation), and we shall describe both a pure BOOTP, and a BOOTP+DHCP configuration, with an emphasis on the latter, which will use the ISC DHCP software package. Configuration Using ISC DHCP DHCP diskless operation The isc-dhcp server can answer both BOOTP and DHCP requests. As of release 4.4, isc-dhcp 3.0 is not part of the base system. You will first need to install the net/isc-dhcp3 port or the corresponding package. Please refer to for general information about ports and packages. Once isc-dhcp is installed, it needs a configuration file to run, (normally named /usr/local/etc/dhcpd.conf). Here follows a commented example: default-lease-time 600; max-lease-time 7200; authoritative; option domain-name "example.com"; option domain-name-servers 192.168.4.1; option routers 192.168.4.1; subnet 192.168.4.0 netmask 255.255.255.0 { use-host-decl-names on; option subnet-mask 255.255.255.0; option broadcast-address 192.168.4.255; host margaux { hardware ethernet 01:23:45:67:89:ab; fixed-address margaux.example.com; next-server 192.168.4.4; filename "/tftpboot/kernel.diskless"; option root-path "192.168.4.4:/data/misc/diskless"; } } This option tells dhcpd to send the value in the host declarations as the hostname for the diskless host. An alternate way would be to add an option host-name margaux inside the host declarations. The next-server directive designates the TFTP server (the default is to use the same host as the DHCP server). The filename directive defines the file that etherboot will load as a kernel. PXE appears to prefer a relative file name, and it loads pxeboot, not the kernel (option filename "pxeboot"). The root-path option defines the path to the root filesystem, in usual NFS notation. Configuration Using BOOTP BOOTP diskless operation Here follows an equivalent bootpd configuration. This would be found in /etc/bootptab. Please note that etherboot must be compiled with the non-default option NO_DHCP_SUPPORT in order to use BOOTP, and that PXE needs DHCP. The only obvious advantage of bootpd is that it exists in the base system. .def100:\ :hn:ht=1:sa=192.168.4.4:vm=rfc1048:\ :sm=255.255.255.0:\ :ds=192.168.4.1:\ :gw=192.168.4.1:\ :hd="/tftpboot":\ :bf="/kernel.diskless":\ :rp="192.168.4.4:/data/misc/diskless": margaux:ha=0123456789ab:tc=.def100 Preparing a Boot Program with <application>Etherboot</application> Etherboot Etherboot's Web site contains extensive documentation mainly intended for Linux systems, but nonetheless containing useful information. The following will just outline how you would use etherboot on a FreeBSD system. You must first install the net/etherboot package or port. The etherboot port can normally be found in /usr/ports/net/etherboot. If the ports tree is installed on your system, just typing make in this directory should take care of everything. Else refer to for information about ports and packages. For our setup, we shall use a boot floppy. For other methods (PROM, or dos program), please refer to the etherboot documentation. To make a boot floppy, insert a floppy in the drive on the machine where you installed etherboot, then change your current directory to the src directory in the etherboot tree and type: &prompt.root; gmake bin32/devicetype.fd0 devicetype depends on the type of the Ethernet card in the diskless workstation. Refer to the NIC file in the same directory to determine the right devicetype. Configuring the TFTP and NFS Servers TFTP diskless operation NFS diskless operation You need to enable tftpd on the TFTP server: Create a directory from which tftpd will serve the files, i.e.: /tftpboot Add this line to your /etc/inetd.conf: tftp dgram udp wait root /usr/libexec/tftpd tftpd -s /tftpboot It appears that at least some PXE versions want the TCP version of TFTP. In this case, add a second line, replacing dgram udp with stream tcp. Tell inetd to reread its configuration file: &prompt.root; kill -HUP `cat /var/run/inetd.pid` You can place the tftpboot directory anywhere on the server. Make sure that the location is set in both inetd.conf and dhcpd.conf. You also need to enable NFS and export the appropriate filesystem on the NFS server. Add this to /etc/rc.conf: nfs_server_enable="YES" Export the filesystem where the diskless root directory is located by adding the following to /etc/exports (adjust the volume mount point and replace margaux with the name of the diskless workstation): /data/misc -alldirs -ro margaux Tell mountd to reread its configuration file. If you actually needed to enable NFS in /etc/rc.conf at the first step, you probably want to reboot instead. &prompt.root; kill -HUP `cat /var/run/mountd.pid` Building a Diskless Kernel diskless operation kernel configuration Create a kernel configuration file for the diskless client with the following options (in addition to the usual ones): options BOOTP # Use BOOTP to obtain IP address/hostname options BOOTP_NFSROOT # NFS mount root filesystem using BOOTP info options BOOTP_COMPAT # Workaround for broken bootp daemons. You may also want to use BOOTP_NFSV3 and BOOTP_WIRED_TO (refer to LINT). Build the kernel (See ), and copy it to the tftp directory, under the name listed in dhcpd.conf. Preparing the root Filesystem root file system diskless operation You need to create a root filesystem for the diskless workstations, in the location listed as root-path in dhcpd.conf. The easiest way to do this is to use the /usr/share/examples/diskless/clone_root shell script. This script needs customization, at least to adjust the place where the filesystem will be created (the DEST variable). Refer to the comments at the top of the script for instructions. They explain how the base filesystem is built, and how files may be selectively overridden by versions specific to diskless operation, to a subnetwork, or to an individual workstation. They also give examples for the diskless /etc/fstab and /etc/rc.conf files. The README files in /usr/share/examples/diskless contain a lot of interesting background information, but, together with the other examples in the diskless directory, they actually document a configuration method which is distinct from the one used by clone_root and /etc/rc.diskless[12], which is a little confusing. Use them for reference only, except if you prefer the method that they describe, in which case you will need customized rc scripts. Configuring Swap If needed, a swap file located on the server can be accessed via NFS. The exact bootptab or dhcpd.conf options are not clearly documented at this time. The following configuration suggestions have been reported to work in some installations using isc-dhcp 3.0rc11. Add the following lines to dhcpd.conf: # Global section option swap-path code 128 = string; option swap-size code 129 = integer 32; host margaux { ... # Standard lines, see above option swap-path "192.168.4.4:/netswapvolume/netswap"; option swap-size 64000; } The idea is that, at least for a FreeBSD client, DHCP/BOOTP option code 128 is the path to the NFS swap file, and option code 129 is the swap size in kilobytes. Older versions of dhcpd allowed a syntax of option option-128 "..., which does not seem to work any more. /etc/bootptab would use the following syntax instead: T128="192.168.4.4:/netswapvolume/netswap":T129=64000 On the NFS swap file server, create the swap file(s) &prompt.root; mkdir /netswapvolume/netswap &prompt.root; cd /netswapvolume/netswap &prompt.root; dd if=/dev/zero bs=1024 count=64000 of=swap.192.168.4.6 &prompt.root; chmod 0600 swap.192.168.4.6 192.168.4.6 is the IP address for the diskless client. On the NFS swap file server, add the following line to /etc/exports: /netswapvolume -maproot=0:10 -alldirs margaux Then tell mountd to reread the exports file, as above. Miscellaneous Issues Running with a read-only <filename>/usr</filename> /usr diskless operation read-only If the diskless workstation is configured to run X, you will have to adjust the xdm configuration file, which puts the error log on /usr by default. Using a non-FreeBSD Server When the server for the root filesystem is not running FreeBSD, you will have to create the root filesystem on a FreeBSD machine, then copy it to its destination, using tar or cpio. In this situation, there are sometimes problems with the special files in /dev, due to differing major/minor integer sizes. A solution to this problem is to export a directory from the non-FreeBSD server, mount this directory onto a FreeBSD machine, and run MAKEDEV on the FreeBSD machine to create the correct device entries (FreeBSD 5.0 and later use &man.devfs.5; to allocate device nodes transparently for the user, running MAKEDEV on these versions is useless). ISDN ISDN A good resource for information on ISDN technology and hardware is Dan Kegel's ISDN Page. A quick simple road map to ISDN follows: If you live in Europe you might want to investigate the ISDN card section. If you are planning to use ISDN primarily to connect to the Internet with an Internet Provider on a dial-up non-dedicated basis, you might look into Terminal Adapters. This will give you the most flexibility, with the fewest problems, if you change providers. If you are connecting two LANs together, or connecting to the Internet with a dedicated ISDN connection, you might consider the stand alone router/bridge option. Cost is a significant factor in determining what solution you will choose. The following options are listed from least expensive to most expensive. Hellmuth Michaelis Contributed by ISDN Cards ISDN cards FreeBSD's ISDN implementation supports only the DSS1/Q.931 (or Euro-ISDN) standard using passive cards. Starting with FreeBSD 4.4, some active cards are supported where the firmware also supports other signaling protocols; this also includes the first supported Primary Rate (PRI) ISDN card. Isdn4bsd allows you to connect to other ISDN routers using either IP over raw HDLC or by using synchronous PPP: either by using kernel PPP with isppp, a modified sppp driver, or by using userland &man.ppp.8;. By using userland &man.ppp.8;, channel bonding of two or more ISDN B-channels is possible. A telephone answering machine application is also available as well as many utilities such as a software 300 Baud modem. Some growing number of PC ISDN cards are supported under FreeBSD and the reports show that it is successfully used all over Europe and in many other parts of the world. The passive ISDN cards supported are mostly the ones with the Infineon (formerly Siemens) ISAC/HSCX/IPAC ISDN chipsets, but also ISDN cards with chips from Cologne Chip (ISA bus only), PCI cards with Winbond W6692 chips, some cards with the Tiger300/320/ISAC chipset combinations and some vendor specific chipset based cards such as the AVM Fritz!Card PCI V.1.0 and the AVM Fritz!Card PnP. Currently the active supported ISDN cards are the AVM B1 (ISA and PCI) BRI cards and the AVM T1 PCI PRI cards. For documentation on isdn4bsd, have a look at /usr/share/examples/isdn/ directory on your FreeBSD system or at the homepage of isdn4bsd which also has pointers to hints, erratas and much more documentation such as the isdn4bsd handbook. In case you are interested in adding support for a different ISDN protocol, a currently unsupported ISDN PC card or otherwise enhancing isdn4bsd, please get in touch with &a.hm;. For questions regarding the installation, configuration and troubleshooting isdn4bsd, a &a.isdn.name; mailing list is available. ISDN Terminal Adapters Terminal adapters(TA), are to ISDN what modems are to regular phone lines. modem Most TA's use the standard hayes modem AT command set, and can be used as a drop in replacement for a modem. A TA will operate basically the same as a modem except connection and throughput speeds will be much faster than your old modem. You will need to configure PPP exactly the same as for a modem setup. Make sure you set your serial speed as high as possible. PPP The main advantage of using a TA to connect to an Internet Provider is that you can do Dynamic PPP. As IP address space becomes more and more scarce, most providers are not willing to provide you with a static IP anymore. Most stand-alone routers are not able to accommodate dynamic IP allocation. TA's completely rely on the PPP daemon that you are running for their features and stability of connection. This allows you to upgrade easily from using a modem to ISDN on a FreeBSD machine, if you already have PPP setup. However, at the same time any problems you experienced with the PPP program and are going to persist. If you want maximum stability, use the kernel PPP option, not the user-land iijPPP. The following TA's are known to work with FreeBSD. Motorola BitSurfer and Bitsurfer Pro Adtran Most other TA's will probably work as well, TA vendors try to make sure their product can accept most of the standard modem AT command set. The real problem with external TA's is that, like modems, you need a good serial card in your computer. You should read the FreeBSD Serial Hardware tutorial for a detailed understanding of serial devices, and the differences between asynchronous and synchronous serial ports. A TA running off a standard PC serial port (asynchronous) limits you to 115.2 Kbs, even though you have a 128 Kbs connection. To fully utilize the 128 Kbs that ISDN is capable of, you must move the TA to a synchronous serial card. Do not be fooled into buying an internal TA and thinking you have avoided the synchronous/asynchronous issue. Internal TA's simply have a standard PC serial port chip built into them. All this will do is save you having to buy another serial cable and find another empty electrical socket. A synchronous card with a TA is at least as fast as a stand-alone router, and with a simple 386 FreeBSD box driving it, probably more flexible. The choice of sync/TA v.s. stand-alone router is largely a religious issue. There has been some discussion of this in the mailing lists. I suggest you search the archives for the complete discussion. Stand-alone ISDN Bridges/Routers ISDN stand-alone bridges/routers ISDN bridges or routers are not at all specific to FreeBSD or any other operating system. For a more complete description of routing and bridging technology, please refer to a Networking reference book. In the context of this page, the terms router and bridge will be used interchangeably. As the cost of low end ISDN routers/bridges comes down, it will likely become a more and more popular choice. An ISDN router is a small box that plugs directly into your local Ethernet network, and manages its own connection to the other bridge/router. It has built in software to communicate via PPP and other popular protocols. A router will allow you much faster throughput than a standard TA, since it will be using a full synchronous ISDN connection. The main problem with ISDN routers and bridges is that interoperability between manufacturers can still be a problem. If you are planning to connect to an Internet provider, you should discuss your needs with them. If you are planning to connect two LAN segments together, such as your home LAN to the office LAN, this is the simplest lowest maintenance solution. Since you are buying the equipment for both sides of the connection you can be assured that the link will work. For example to connect a home computer or branch office network to a head office network the following setup could be used. Branch Office or Home Network 10 base 2 Network uses a bus based topology with 10 base 2 Ethernet (thinnet). Connect router to network cable with AUI/10BT transceiver, if necessary. ---Sun workstation | ---FreeBSD box | ---Windows 95 (Do not admit to owning it) | Stand-alone router | ISDN BRI line 10 Base 2 Ethernet If your home/branch office is only one computer you can use a twisted pair crossover cable to connect to the stand-alone router directly. Head Office or Other LAN 10 base T Network uses a star topology with 10 base T Ethernet (Twisted Pair). -------Novell Server | H | | ---Sun | | | U ---FreeBSD | | | ---Windows 95 | B | |___---Stand-alone router | ISDN BRI line ISDN Network Diagram One large advantage of most routers/bridges is that they allow you to have 2 separate independent PPP connections to 2 separate sites at the same time. This is not supported on most TA's, except for specific (usually expensive) models that have two serial ports. Do not confuse this with channel bonding, MPP, etc. This can be a very useful feature if, for example, you have an dedicated ISDN connection at your office and would like to tap into it, but do not want to get another ISDN line at work. A router at the office location can manage a dedicated B channel connection (64 Kbps) to the Internet and use the other B channel for a separate data connection. The second B channel can be used for dial-in, dial-out or dynamically bonding (MPP, etc.) with the first B channel for more bandwidth. IPX/SPX An Ethernet bridge will also allow you to transmit more than just IP traffic. You can also send IPX/SPX or whatever other protocols you use. Bill Swingle Written by Eric Ogren Enhanced by Udo Erdelhoff NIS/YP What Is It? NIS Solaris HP-UX AIX Linux NetBSD OpenBSD NIS, which stands for Network Information Services, was developed by Sun Microsystems to centralize administration of Unix (originally SunOS) systems. It has now essentially become an industry standard; all major Unix systems (Solaris, HP-UX, AIX, Linux, NetBSD, OpenBSD, FreeBSD, etc) support NIS. yellow pagesNIS NIS was formerly known as Yellow Pages, but because of trademark issues, Sun changed the name. The old term (and yp) is still often seen and used. NIS domains It is a RPC-based client/server system that allows a group of machines within an NIS domain to share a common set of configuration files. This permits a system administrator to set up NIS client systems with only minimal configuration data and add, remove or modify configuration data from a single location. Windows NT It is similar to Windows NT's domain system; although the internal implementation of the two are not at all similar, the basic functionality can be compared. Terms/Processes You Should Know There are several terms and several important user processes that you will come across when attempting to implement NIS on FreeBSD, whether you are trying to create an NIS server or act as an NIS client: portmap Term Description NIS domainname An NIS master server and all of its clients (including its slave servers) have a NIS domainname. Similar to an NT domain name, the NIS domainname does not have anything to do with DNS. portmap Must be running in order to enable RPC (Remote Procedure Call, a network protocol used by NIS). If portmap is not running, it will be impossible to run an NIS server, or to act as an NIS client. ypbind binds an NIS client to its NIS server. It will take the NIS domainname from the system, and using RPC, connect to the server. ypbind is the core of client-server communication in an NIS environment; if ypbind dies on a client machine, it will not be able to access the NIS server. ypserv Should only be running on NIS servers, is the NIS server process itself. If &man.ypserv.8; dies, then the server will no longer be able to respond to NIS requests (hopefully, there is a slave server to take over for it). There are some implementations of NIS (but not the FreeBSD one), that do not try to reconnect to another server if the server it used before dies. Often, the only thing that helps in this case is to restart the server process (or even the whole server) or the ypbind process on the client. rpc.yppasswdd Another process that should only be running on NIS master servers, is a daemon that will allow NIS clients to change their NIS passwords. If this daemon is not running, users will have to login to the NIS master server and change their passwords there. How Does It Work? There are three types of hosts in an NIS environment: master servers, slave servers, and clients. Servers act as a central repository for host configuration information. Master servers hold the authoritative copy of this information, while slave servers mirror this information for redundancy. Clients rely on the servers to provide this information to them. Information in many files can be shared in this manner. The master.passwd, group, and hosts files are commonly shared via NIS. Whenever a process on a client needs information that would normally be found in these files locally, it makes a query to the NIS server that it is bound to instead. Machine Types NIS master server A NIS master server. This server, analogous to a Windows NT primary domain controller, maintains the files used by all of the NIS clients. The passwd, group, and other various files used by the NIS clients live on the master server. It is possible for one machine to be an NIS master server for more than one NIS domain. However, this will not be covered in this introduction, which assumes a relatively small-scale NIS environment. NIS slave server NIS slave servers. Similar to NT's backup domain controllers, NIS slave servers maintain copies of the NIS master's data files. NIS slave servers provide the redundancy, which is needed in important environments. They also help to balance the load of the master server: NIS Clients always attach to the NIS server whose response they get first, and this includes slave-server-replies. NIS client NIS clients. NIS clients, like most NT workstations, authenticate against the NIS server (or the NT domain controller in the NT Workstation case) to log on. Using NIS/YP This section will deal with setting up a sample NIS environment. This section assumes that you are running FreeBSD 3.3 or later. The instructions given here will probably work for any version of FreeBSD greater than 3.0, but there are no guarantees that this is true. Planning Let us assume that you are the administrator of a small university lab. This lab, which consists of 15 FreeBSD machines, currently has no centralized point of administration; each machine has its own /etc/passwd and /etc/master.passwd. These files are kept in sync with each other only through manual intervention; currently, when you add a user to the lab, you must run adduser on all 15 machines. Clearly, this has to change, so you have decided to convert the lab to use NIS, using two of the machines as servers. Therefore, the configuration of the lab now looks something like: Machine name IP address Machine role ellington 10.0.0.2 NIS master coltrane 10.0.0.3 NIS slave basie 10.0.0.4 Faculty workstation bird 10.0.0.5 Client machine cli[1-11] 10.0.0.[6-17] Other client machines If you are setting up a NIS scheme for the first time, it is a good idea to think through how you want to go about it. No matter what the size of your network, there are a few decisions that need to be made. Choosing a NIS Domain Name NIS domainname This might not be the domainname that you are used to. It is more accurately called the NIS domainname. When a client broadcasts its requests for info, it includes the name of the NIS domain that it is part of. This is how multiple servers on one network can tell which server should answer which request. Think of the NIS domainname as the name for a group of hosts that are related in some way. Some organizations choose to use their Internet domainname for their NIS domainname. This is not recommended as it can cause confusion when trying to debug network problems. The NIS domainname should be unique within your network and it is helpful if it describes the group of machines it represents. For example, the Art department at Acme Inc. might be in the acme-art NIS domain. For this example, assume you have chosen the name test-domain. SunOS However, some operating systems (notably SunOS) use their NIS domain name as their Internet domain name. If one or more machines on your network have this restriction, you must use the Internet domain name as your NIS domain name. Physical Server Requirements There are several things to keep in mind when choosing a machine to use as a NIS server. One of the unfortunate things about NIS is the level of dependency the clients have on the server. If a client cannot contact the server for its NIS domain, very often the machine becomes unusable. The lack of user and group information causes most systems to temporarily freeze up. With this in mind you should make sure to choose a machine that will not be prone to being rebooted regularly, or one that might be used for development. The NIS server should ideally be a stand alone machine whose sole purpose in life is to be an NIS server. If you have a network that is not very heavily used, it is acceptable to put the NIS server on a machine running other services, just keep in mind that if the NIS server becomes unavailable, it will affect all of your NIS clients adversely. NIS Servers The canonical copies of all NIS information are stored on a single machine called the NIS master server. The databases used to store the information are called NIS maps. In FreeBSD, these maps are stored in /var/yp/[domainname] where [domainname] is the name of the NIS domain being served. A single NIS server can support several domains at once, therefore it is possible to have several such directories, one for each supported domain. Each domain will have its own independent set of maps. NIS master and slave servers handle all NIS requests with the ypserv daemon. ypserv is responsible for receiving incoming requests from NIS clients, translating the requested domain and map name to a path to the corresponding database file and transmitting data from the database back to the client. Setting Up a NIS Master Server NIS server configuration Setting up a master NIS server can be relatively straight forward, depending on your needs. FreeBSD comes with support for NIS out-of-the-box. All you need is to add the following lines to /etc/rc.conf, and FreeBSD will do the rest for you. nisdomainname="test-domain" This line will set the NIS domainname to test-domain upon network setup (e.g. after reboot). nis_server_enable="YES" This will tell FreeBSD to start up the NIS server processes when the networking is next brought up. nis_yppasswdd_enable="YES" This will enable the rpc.yppasswdd daemon which, as mentioned above, will allow users to change their NIS password from a client machine. Depending on your NIS setup, you may need to add further entries. See the section about NIS servers that are also NIS clients, below, for details. Now, all you have to do is to run the command /etc/netstart as superuser. It will set up everything for you, using the values you defined in /etc/rc.conf. Initializing the NIS Maps NIS maps The NIS maps are database files, that are kept in the /var/yp directory. They are generated from configuration files in the /etc directory of the NIS master, with one exception: the /etc/master.passwd file. This is for a good reason; you do not want to propagate passwords to your root and other administrative accounts to all the servers in the NIS domain. Therefore, before we initialize the NIS maps, you should: &prompt.root; cp /etc/master.passwd /var/yp/master.passwd &prompt.root; cd /var/yp &prompt.root; vi master.passwd You should remove all entries regarding system accounts (bin, tty, kmem, games, etc), as well as any accounts that you do not want to be propagated to the NIS clients (for example root and any other UID 0 (superuser) accounts). Make sure the /var/yp/master.passwd is neither group nor world readable (mode 600)! Use the chmod command, if appropriate. Tru64 Unix When you have finished, it is time to initialize the NIS maps! FreeBSD includes a script named ypinit to do this for you (see its manual page for more information). Note that this script is available on most Unix Operating Systems, but not on all. On Digital Unix/Compaq Tru64 Unix it is called ypsetup. Because we are generating maps for an NIS master, we are going to pass the option to ypinit. To generate the NIS maps, assuming you already performed the steps above, run: ellington&prompt.root; ypinit -m test-domain Server Type: MASTER Domain: test-domain Creating an YP server will require that you answer a few questions. Questions will all be asked at the beginning of the procedure. Do you want this procedure to quit on non-fatal errors? [y/n: n] n Ok, please remember to go back and redo manually whatever fails. If you don't, something might not work. At this point, we have to construct a list of this domains YP servers. rod.darktech.org is already known as master server. Please continue to add any slave servers, one per line. When you are done with the list, type a <control D>. master server : ellington next host to add: coltrane next host to add: ^D The current list of NIS servers looks like this: ellington coltrane Is this correct? [y/n: y] y [..output from map generation..] NIS Map update completed. ellington has been setup as an YP master server without any errors. ypinit should have created /var/yp/Makefile from /var/yp/Makefile.dist. When created, this file assumes that you are operating in a single server NIS environment with only FreeBSD machines. Since test-domain has a slave server as well, you must edit /var/yp/Makefile: ellington&prompt.root; vi /var/yp/Makefile You should comment out the line that says NOPUSH = "True" (if it is not commented out already). Setting up a NIS Slave Server NIS slave server Setting up an NIS slave server is even more simple than setting up the master. Log on to the slave server and edit the file /etc/rc.conf as you did before. The only difference is that we now must use the option when running ypinit. The option requires the name of the NIS master be passed to it as well, so our command line looks like: coltrane&prompt.root; ypinit -s ellington test-domain Server Type: SLAVE Domain: test-domain Master: ellington Creating an YP server will require that you answer a few questions. Questions will all be asked at the beginning of the procedure. Do you want this procedure to quit on non-fatal errors? [y/n: n] n Ok, please remember to go back and redo manually whatever fails. If you don't, something might not work. There will be no further questions. The remainder of the procedure should take a few minutes, to copy the databases from ellington. Transferring netgroup... ypxfr: Exiting: Map successfully transferred Transferring netgroup.byuser... ypxfr: Exiting: Map successfully transferred Transferring netgroup.byhost... ypxfr: Exiting: Map successfully transferred Transferring master.passwd.byuid... ypxfr: Exiting: Map successfully transferred Transferring passwd.byuid... ypxfr: Exiting: Map successfully transferred Transferring passwd.byname... ypxfr: Exiting: Map successfully transferred Transferring group.bygid... ypxfr: Exiting: Map successfully transferred Transferring group.byname... ypxfr: Exiting: Map successfully transferred Transferring services.byname... ypxfr: Exiting: Map successfully transferred Transferring rpc.bynumber... ypxfr: Exiting: Map successfully transferred Transferring rpc.byname... ypxfr: Exiting: Map successfully transferred Transferring protocols.byname... ypxfr: Exiting: Map successfully transferred Transferring master.passwd.byname... ypxfr: Exiting: Map successfully transferred Transferring networks.byname... ypxfr: Exiting: Map successfully transferred Transferring networks.byaddr... ypxfr: Exiting: Map successfully transferred Transferring netid.byname... ypxfr: Exiting: Map successfully transferred Transferring hosts.byaddr... ypxfr: Exiting: Map successfully transferred Transferring protocols.bynumber... ypxfr: Exiting: Map successfully transferred Transferring ypservers... ypxfr: Exiting: Map successfully transferred Transferring hosts.byname... ypxfr: Exiting: Map successfully transferred coltrane has been setup as an YP slave server without any errors. Don't forget to update map ypservers on ellington. You should now have a directory called /var/yp/test-domain. Copies of the NIS master server's maps should be in this directory. You will need to make sure that these stay updated. The following /etc/crontab entries on your slave servers should do the job: 20 * * * * root /usr/libexec/ypxfr passwd.byname 21 * * * * root /usr/libexec/ypxfr passwd.byuid These two lines force the slave to sync its maps with the maps on the master server. Although these entries are not mandatory, since the master server attempts to ensure any changes to its NIS maps are communicated to its slaves and because password information is vital to systems depending on the server, it is a good idea to force the updates. This is more important on busy networks where map updates might not always complete. Now, run the command /etc/netstart on the slave server as well, which again starts the NIS server. NIS Clients An NIS client establishes what is called a binding to a particular NIS server using the ypbind daemon. ypbind checks the system's default domain (as set by the domainname command), and begins broadcasting RPC requests on the local network. These requests specify the name of the domain for which ypbind is attempting to establish a binding. If a server that has been configured to serve the requested domain receives one of the broadcasts, it will respond to ypbind, which will record the server's address. If there are several servers available (a master and several slaves, for example), ypbind will use the address of the first one to respond. From that point on, the client system will direct all of its NIS requests to that server. ypbind will occasionally ping the server to make sure it is still up and running. If it fails to receive a reply to one of its pings within a reasonable amount of time, ypbind will mark the domain as unbound and begin broadcasting again in the hopes of locating another server. Setting Up an NIS Client NIS client configuration Setting up a FreeBSD machine to be a NIS client is fairly straightforward. Edit the file /etc/rc.conf and add the following lines in order to set the NIS domainname and start ypbind upon network startup: nisdomainname="test-domain" nis_client_enable="YES" To import all possible password entries from the NIS server, remove all user accounts from your /etc/master.passwd file and use vipw to add the following line to the end of the file: +::::::::: This line will afford anyone with a valid account in the NIS server's password maps an account. There are many ways to configure your NIS client by changing this line. See the netgroups section below for more information. For more detailed reading see O'Reilly's book on Managing NFS and NIS. You should keep at least one local account (i.e. not imported via NIS) in your /etc/master.passwd and this account should also be a member of the group wheel. If there is something wrong with NIS, this account can be used to log in remotely, become root, and fix things. To import all possible group entries from the NIS server, add this line to your /etc/group file: +:*:: After completing these steps, you should be able to run ypcat passwd and see the NIS server's passwd map. NIS Security In general, any remote user can issue an RPC to &man.ypserv.8; and retrieve the contents of your NIS maps, provided the remote user knows your domainname. To prevent such unauthorized transactions, &man.ypserv.8; supports a feature called securenets which can be used to restrict access to a given set of hosts. At startup, &man.ypserv.8; will attempt to load the securenets information from a file called /var/yp/securenets. This path varies depending on the path specified with the option. This file contains entries that consist of a network specification and a network mask separated by white space. Lines starting with # are considered to be comments. A sample securenets file might look like this: # allow connections from local host -- mandatory 127.0.0.1 255.255.255.255 # allow connections from any host # on the 192.168.128.0 network 192.168.128.0 255.255.255.0 # allow connections from any host # between 10.0.0.0 to 10.0.15.255 # this includes the machines in the testlab 10.0.0.0 255.255.240.0 If &man.ypserv.8; receives a request from an address that matches one of these rules, it will process the request normally. If the address fails to match a rule, the request will be ignored and a warning message will be logged. If the /var/yp/securenets file does not exist, ypserv will allow connections from any host. The ypserv program also has support for Wietse Venema's tcpwrapper package. This allows the administrator to use the tcpwrapper configuration files for access control instead of /var/yp/securenets. While both of these access control mechanisms provide some security, they, like the privileged port test, are vulnerable to IP spoofing attacks. All NIS-related traffic should be blocked at your firewall. Servers using /var/yp/securenets may fail to serve legitimate NIS clients with archaic TCP/IP implementations. Some of these implementations set all host bits to zero when doing broadcasts and/or fail to observe the subnet mask when calculating the broadcast address. While some of these problems can be fixed by changing the client configuration, other problems may force the retirement of the client systems in question or the abandonment of /var/yp/securenets. Using /var/yp/securenets on a server with such an archaic implementation of TCP/IP is a really bad idea and will lead to loss of NIS functionality for large parts of your network. tcpwrapper The use of the tcpwrapper package increases the latency of your NIS server. The additional delay may be long enough to cause timeouts in client programs, especially in busy networks or with slow NIS servers. If one or more of your client systems suffers from these symptoms, you should convert the client systems in question into NIS slave servers and force them to bind to themselves. Barring Some Users from Logging On In our lab, there is a machine basie that is supposed to be a faculty only workstation. We do not want to take this machine out of the NIS domain, yet the passwd file on the master NIS server contains accounts for both faculty and students. What can we do? There is a way to bar specific users from logging on to a machine, even if they are present in the NIS database. To do this, all you must do is add -username to the end of the /etc/master.passwd file on the client machine, where username is the username of the user you wish to bar from logging in. This should preferably be done using vipw, since vipw will sanity check your changes to /etc/master.passwd, as well as automatically rebuild the password database when you finish editing. For example, if we wanted to bar user bill from logging on to basie we would: basie&prompt.root; vipw [add -bill to the end, exit] vipw: rebuilding the database... vipw: done basie&prompt.root; cat /etc/master.passwd root:[password]:0:0::0:0:The super-user:/root:/bin/csh toor:[password]:0:0::0:0:The other super-user:/root:/bin/sh daemon:*:1:1::0:0:Owner of many system processes:/root:/sbin/nologin operator:*:2:5::0:0:System &:/:/sbin/nologin bin:*:3:7::0:0:Binaries Commands and Source,,,:/:/sbin/nologin tty:*:4:65533::0:0:Tty Sandbox:/:/sbin/nologin kmem:*:5:65533::0:0:KMem Sandbox:/:/sbin/nologin games:*:7:13::0:0:Games pseudo-user:/usr/games:/sbin/nologin news:*:8:8::0:0:News Subsystem:/:/sbin/nologin man:*:9:9::0:0:Mister Man Pages:/usr/share/man:/sbin/nologin bind:*:53:53::0:0:Bind Sandbox:/:/sbin/nologin uucp:*:66:66::0:0:UUCP pseudo-user:/var/spool/uucppublic:/usr/libexec/uucp/uucico xten:*:67:67::0:0:X-10 daemon:/usr/local/xten:/sbin/nologin pop:*:68:6::0:0:Post Office Owner:/nonexistent:/sbin/nologin nobody:*:65534:65534::0:0:Unprivileged user:/nonexistent:/sbin/nologin +::::::::: -bill basie&prompt.root; Udo Erdelhoff Contributed by Using Netgroups netgroups The method shown in the previous section works reasonably well if you need special rules for a very small number of users and/or machines. On larger networks, you will forget to bar some users from logging onto sensitive machines, or you may even have to modify each machine separately, thus losing the main benefit of NIS, centralized administration. The NIS developers' solution for this problem is called netgroups. Their purpose and semantics can be compared to the normal groups used by Unix file systems. The main differences are the lack of a numeric id and the ability to define a netgroup by including both user accounts and other netgroups. Netgroups were developed to handle large, complex networks with hundreds of users and machines. On one hand, this is a Good Thing if you are forced to deal with such a situation. On the other hand, this complexity makes it almost impossible to explain netgroups with really simple examples. The example used in the remainder of this section demonstrates this problem. Let us assume that your successful introduction of NIS in your laboratory caught your superiors' interest. Your next job is to extend your NIS domain to cover some of the other machines on campus. The two tables contain the names of the new users and new machines as well as brief descriptions of them. User Name(s) Description alpha, beta Normal employees of the IT department charlie, delta The new apprentices of the IT department echo, foxtrott, golf, ... Ordinary employees able, baker, ... The current interns Machine Name(s) Description war, death, famine, pollution Your most important servers. Only the IT employees are allowed to log onto these machines. pride, greed, envy, wrath, lust, sloth Less important servers. All members of the IT department are allowed to login onto these machines. one, two, three, four, ... Ordinary workstations. Only the real employees are allowed to use these machines. trashcan A very old machine without any critical data. Even the intern is allowed to use this box. If you tried to implement these restrictions by separately blocking each user, you would have to add one -user line to each system's passwd for each user who is not allowed to login onto that system. If you forget just one entry, you could be in trouble. It may be feasible to do this correctly during the initial setup, however you will eventually forget to add the lines for new users during day-to-day operations. After all, Murphy was an optimist. Handling this situation with netgroups offers several advantages. Each user need not be handled separately; you assign a user to one or more netgroups and allow or forbid logins for all members of the netgroup. If you add a new machine, you will only have to define login restrictions for netgroups. If a new user is added, you will only have to add the user to one or more netgroups. Those changes are independent of each other; no more for each combination of user and machine do... If your NIS setup is planned carefully, you will only have to modify exactly one central configuration file to grant or deny access to machines. The first step is the initialization of the NIS map netgroup. FreeBSD's &man.ypinit.8; does not create this map by default, but its NIS implementation will support it once it has been created. To create an empty map, simply type ellington&prompt.root; vi /var/yp/netgroup and start adding content. For our example, we need at least four netgroups: IT employees, IT apprentices, normal employees and interns. IT_EMP (,alpha,test-domain) (,beta,test-domain) IT_APP (,charlie,test-domain) (,delta,test-domain) USERS (,echo,test-domain) (,foxtrott,test-domain) \ (,golf,test-domain) INTERNS (,able,test-domain) (,baker,test-domain) IT_EMP, IT_APP etc. are the names of the netgroups. Each bracketed group adds one or more user accounts to it. The three fields inside a group are: The name of the host(s) where the following items are valid. If you do not specify a hostname, the entry is valid on all hosts. If you do specify a hostname, you will enter a realm of darkness, horror and utter confusion. The name of the account that belongs to this netgroup. The NIS domain for the account. You can import accounts from other NIS domains into your netgroup if you are one of the unlucky fellows with more than one NIS domain. Each of these fields can contain wildcards. See &man.netgroup.5; for details. netgroups Netgroup names longer than 8 characters should not be used, especially if you have machines running other operating systems within your NIS domain. The names are case sensitive; using capital letters for your netgroup names is an easy way to distinguish between user, machine and netgroup names. Some NIS clients (other than FreeBSD) cannot handle netgroups with a large number of entries. For example, some older versions of SunOS start to cause trouble if a netgroup contains more than 15 entries. You can circumvent this limit by creating several sub-netgroups with 15 users or less and a real netgroup that consists of the sub-netgroups: BIGGRP1 (,joe1,domain) (,joe2,domain) (,joe3,domain) [...] BIGGRP2 (,joe16,domain) (,joe17,domain) [...] BIGGRP3 (,joe31,domain) (,joe32,domain) BIGGROUP BIGGRP1 BIGGRP2 BIGGRP3 You can repeat this process if you need more than 225 users within a single netgroup. Activating and distributing your new NIS map is easy: ellington&prompt.root; cd /var/yp ellington&prompt.root; make This will generate the three NIS maps netgroup, netgroup.byhost and netgroup.byuser. Use &man.ypcat.1; to check if your new NIS maps are available: ellington&prompt.user; ypcat -k netgroup ellington&prompt.user; ypcat -k netgroup.byhost ellington&prompt.user; ypcat -k netgroup.byuser The output of the first command should resemble the contents of /var/yp/netgroup. The second command will not produce output if you have not specified host-specific netgroups. The third command can be used to get the list of netgroups for a user. The client setup is quite simple. To configure the server war, you only have to start &man.vipw.8; and replace the line +::::::::: with +@IT_EMP::::::::: Now, only the data for the users defined in the netgroup IT_EMP is imported into war's password database and only these users are allowed to login. Unfortunately, this limitation also applies to the ~ function of the shell and all routines converting between user names and numerical user IDs. In other words, cd ~user will not work, ls -l will show the numerical id instead of the username and find . -user joe -print will fail with No such user. To fix this, you will have to import all user entries without allowing them to login onto your servers. This can be achieved by adding another line to /etc/master.passwd. This line should contain: +:::::::::/sbin/nologin, meaning Import all entries but replace the shell with /sbin/nologin in the imported entries. You can replace any field in the passwd entry by placing a default value in your /etc/master.passwd. Make sure that the line +:::::::::/sbin/nologin is placed after +@IT_EMP:::::::::. Otherwise, all user accounts imported from NIS will have /sbin/nologin as their login shell. After this change, you will only have to change one NIS map if a new employee joins the IT department. You could use a similar approach for the less important servers by replacing the old +::::::::: in their local version of /etc/master.passwd with something like this: +@IT_EMP::::::::: +@IT_APP::::::::: +:::::::::/sbin/nologin The corresponding lines for the normal workstations could be: +@IT_EMP::::::::: +@USERS::::::::: +:::::::::/sbin/nologin And everything would be fine until there is a policy change a few weeks later: The IT department starts hiring interns. The IT interns are allowed to use the normal workstations and the less important servers; and the IT apprentices are allowed to login onto the main servers. You add a new netgroup IT_INTERN, add the new IT interns to this netgroup and start to change the config on each and every machine... As the old saying goes: Errors in centralized planning lead to global mess. NIS' ability to create netgroups from other netgroups can be used to prevent situations like these. One possibility is the creation of role-based netgroups. For example, you could create a netgroup called BIGSRV to define the login restrictions for the important servers, another netgroup called SMALLSRV for the less important servers and a third netgroup called USERBOX for the normal workstations. Each of these netgroups contains the netgroups that are allowed to login onto these machines. The new entries for your NIS map netgroup should look like this: BIGSRV IT_EMP IT_APP SMALLSRV IT_EMP IT_APP ITINTERN USERBOX IT_EMP ITINTERN USERS This method of defining login restrictions works reasonably well if you can define groups of machines with identical restrictions. Unfortunately, this is the exception and not the rule. Most of the time, you will need the ability to define login restrictions on a per-machine basis. Machine-specific netgroup definitions are the other possibility to deal with the policy change outlined above. In this scenario, the /etc/master.passwd of each box contains two lines starting with +. The first of them adds a netgroup with the accounts allowed to login onto this machine, the second one adds all other accounts with /sbin/nologin as shell. It is a good idea to use the ALL-CAPS version of the machine name as the name of the netgroup. In other words, the lines should look like this: +@BOXNAME::::::::: +:::::::::/sbin/nologin Once you have completed this task for all your machines, you will not have to modify the local versions of /etc/master.passwd ever again. All further changes can be handled by modifying the NIS map. Here is an example of a possible netgroup map for this scenario with some additional goodies. # Define groups of users first IT_EMP (,alpha,test-domain) (,beta,test-domain) IT_APP (,charlie,test-domain) (,delta,test-domain) DEPT1 (,echo,test-domain) (,foxtrott,test-domain) DEPT2 (,golf,test-domain) (,hotel,test-domain) DEPT3 (,india,test-domain) (,juliet,test-domain) ITINTERN (,kilo,test-domain) (,lima,test-domain) D_INTERNS (,able,test-domain) (,baker,test-domain) # # Now, define some groups based on roles USERS DEPT1 DEPT2 DEPT3 BIGSRV IT_EMP IT_APP SMALLSRV IT_EMP IT_APP ITINTERN USERBOX IT_EMP ITINTERN USERS # # And a groups for a special tasks # Allow echo and golf to access our anti-virus-machine SECURITY IT_EMP (,echo,test-domain) (,golf,test-domain) # # machine-based netgroups # Our main servers WAR BIGSRV FAMINE BIGSRV # User india needs access to this server POLLUTION BIGSRV (,india,test-domain) # # This one is really important and needs more access restrictions DEATH IT_EMP # # The anti-virus-machine mentioned above ONE SECURITY # # Restrict a machine to a single user TWO (,hotel,test-domain) # [...more groups to follow] If you are using some kind of database to manage your user accounts, you should be able to create the first part of the map with your database's report tools. This way, new users will automatically have access to the boxes. One last word of caution: It may not always be advisable to use machine-based netgroups. If you are deploying a couple of dozen or even hundreds of identical machines for student labs, you should use role-based netgroups instead of machine-based netgroups to keep the size of the NIS map within reasonable limits. Important Things to Remember There are still a couple of things that you will need to do differently now that you are in an NIS environment. Every time you wish to add a user to the lab, you must add it to the master NIS server only, and you must remember to rebuild the NIS maps. If you forget to do this, the new user will not be able to login anywhere except on the NIS master. For example, if we needed to add a new user jsmith to the lab, we would: &prompt.root; pw useradd jsmith &prompt.root; cd /var/yp &prompt.root; make test-domain You could also run adduser jsmith instead of pw useradd jsmith. Keep the administration accounts out of the NIS maps. You do not want to be propagating administrative accounts and passwords to machines that will have users that should not have access to those accounts. Keep the NIS master and slave secure, and minimize their downtime. If somebody either hacks or simply turns off these machines, they have effectively rendered many people without the ability to login to the lab. This is the chief weakness of any centralized administration system, and it is probably the most important weakness. If you do not protect your NIS servers, you will have a lot of angry users! NIS v1 Compatibility FreeBSD's ypserv has some support for serving NIS v1 clients. FreeBSD's NIS implementation only uses the NIS v2 protocol, however other implementations include support for the v1 protocol for backwards compatibility with older systems. The ypbind daemons supplied with these systems will try to establish a binding to an NIS v1 server even though they may never actually need it (and they may persist in broadcasting in search of one even after they receive a response from a v2 server). Note that while support for normal client calls is provided, this version of ypserv does not handle v1 map transfer requests; consequently, it cannot be used as a master or slave in conjunction with older NIS servers that only support the v1 protocol. Fortunately, there probably are not any such servers still in use today. NIS Servers that are also NIS Clients Care must be taken when running ypserv in a multi-server domain where the server machines are also NIS clients. It is generally a good idea to force the servers to bind to themselves rather than allowing them to broadcast bind requests and possibly become bound to each other. Strange failure modes can result if one server goes down and others are dependent upon it. Eventually all the clients will time out and attempt to bind to other servers, but the delay involved can be considerable and the failure mode is still present since the servers might bind to each other all over again. You can force a host to bind to a particular server by running ypbind with the flag. If you do not want to do this manually each time you reboot your NIS server, you can add the following lines to your /etc/rc.conf: nis_client_enable="YES" # run client stuff as well nis_client_flags="-S NIS domain,server" See &man.ypbind.8; for further information. libscrypt v.s. libdescrypt NIS crypto library One of the most common issues that people run into when trying to implement NIS is crypt library compatibility. If your NIS server is using the DES crypt libraries, it will only support clients that are using DES as well. To check which one your server and clients are using look at the symlinks in /usr/lib. If the machine is configured to use the DES libraries, it will look something like this: &prompt.user; ls -l /usr/lib/*crypt* lrwxrwxrwx 1 root wheel 13 Jul 15 08:55 libcrypt.a@ -> libdescrypt.a lrwxrwxrwx 1 root wheel 14 Jul 15 08:55 libcrypt.so@ -> libdescrypt.so lrwxrwxrwx 1 root wheel 16 Jul 15 08:55 libcrypt.so.2@ -> libdescrypt.so.2 lrwxrwxrwx 1 root wheel 15 Jul 15 08:55 libcrypt_p.a@ -> libdescrypt_p.a -r--r--r-- 1 root wheel 13018 Nov 8 14:27 libdescrypt.a lrwxr-xr-x 1 root wheel 16 Nov 8 14:27 libdescrypt.so@ -> libdescrypt.so.2 -r--r--r-- 1 root wheel 12965 Nov 8 14:27 libdescrypt.so.2 -r--r--r-- 1 root wheel 14750 Nov 8 14:27 libdescrypt_p.a If the machine is configured to use the standard FreeBSD MD5 crypt libraries they will look something like this: &prompt.user; ls -l /usr/lib/*crypt* lrwxrwxrwx 1 root wheel 13 Jul 15 08:55 libcrypt.a@ -> libscrypt.a lrwxrwxrwx 1 root wheel 14 Jul 15 08:55 libcrypt.so@ -> libscrypt.so lrwxrwxrwx 1 root wheel 16 Jul 15 08:55 libcrypt.so.2@ -> libscrypt.so.2 lrwxrwxrwx 1 root wheel 15 Jul 15 08:55 libcrypt_p.a@ -> libscrypt_p.a -r--r--r-- 1 root wheel 6194 Nov 8 14:27 libscrypt.a lrwxr-xr-x 1 root wheel 14 Nov 8 14:27 libscrypt.so@ -> libscrypt.so.2 -r--r--r-- 1 root wheel 7579 Nov 8 14:27 libscrypt.so.2 -r--r--r-- 1 root wheel 6684 Nov 8 14:27 libscrypt_p.a If you have trouble authenticating on an NIS client, this is a pretty good place to start looking for possible problems. If you want to deploy an NIS server for a heterogenous network, you will probably have to use DES on all systems because it is the lowest common standard. Greg Sutter Written by DHCP What Is DHCP? Dynamic Host Configuration Protocol DHCP Internet Software Consortium (ISC) DHCP, the Dynamic Host Configuration Protocol, describes the means by which a system can connect to a network and obtain the necessary information for communication upon that network. FreeBSD uses the ISC (Internet Software Consortium) DHCP implementation, so all implementation-specific information here is for use with the ISC distribution. What this Section Covers This section describes both the client-side and server-side components of the ISC DHCP system. The client-side program, dhclient, comes integrated within FreeBSD, and the server-side portion is available from the net/isc-dhcp3 port. The &man.dhclient.8;, &man.dhcp-options.5;, and &man.dhclient.conf.5; manual pages, in addition to the references below, are useful resources. How It Works UDP When dhclient, the DHCP client, is executed on the client machine, it begins broadcasting requests for configuration information. By default, these requests are on UDP port 68. The server replies on UDP 67, giving the client an IP address and other relevant network information such as netmask, router, and DNS servers. All of this information comes in the form of a DHCP lease and is only valid for a certain time (configured by the DHCP server maintainer). In this manner, stale IP addresses for clients no longer connected to the network can be automatically reclaimed. DHCP clients can obtain a great deal of information from the server. An exhaustive list may be found in &man.dhcp-options.5;. FreeBSD Integration FreeBSD fully integrates the ISC DHCP client, dhclient. DHCP client support is provided within both the installer and the base system, obviating the need for detailed knowledge of network configurations on any network that runs a DHCP server. dhclient has been included in all FreeBSD distributions since 3.2. sysinstall DHCP is supported by sysinstall. When configuring a network interface within sysinstall, the first question asked is, Do you want to try DHCP configuration of this interface? Answering affirmatively will execute dhclient, and if successful, will fill in the network configuration information automatically. There are two things you must do to have your system use DHCP upon startup: DHCP requirements Make sure that the bpf device is compiled into your kernel. To do this, add pseudo-device bpf to your kernel configuration file, and rebuild the kernel. For more information about building kernels, see . The bpf device is already part of the GENERIC kernel that is supplied with FreeBSD, so if you do not have a custom kernel, you should not need to create one in order to get DHCP working. For those who are particularly security conscious, you should be warned that bpf is also the device that allows packet sniffers to work correctly (although they still have to be run as root). bpf is required to use DHCP, but if you are very sensitive about security, you probably should not add bpf to your kernel in the expectation that at some point in the future you will be using DHCP. Edit your /etc/rc.conf to include the following: ifconfig_fxp0="DHCP" Be sure to replace fxp0 with the designation for the interface that you wish to dynamically configure, as described in . If you are using a different location for dhclient, or if you wish to pass additional flags to dhclient, also include the following (editing as necessary): dhcp_program="/sbin/dhclient" dhcp_flags="" DHCP server The DHCP server, dhcpd, is included as part of the net/isc-dhcp3 port in the ports collection. This port contains the full ISC DHCP distribution, consisting of client, server, relay agent and documentation. Files DHCP configuration files /etc/dhclient.conf dhclient requires a configuration file, /etc/dhclient.conf. Typically the file contains only comments, the defaults being reasonably sane. This configuration file is described by the &man.dhclient.conf.5; manual page. /sbin/dhclient dhclient is statically linked and resides in /sbin. The &man.dhclient.8; manual page gives more information about dhclient. /sbin/dhclient-script dhclient-script is the FreeBSD-specific DHCP client configuration script. It is described in &man.dhclient-script.8;, but should not need any user modification to function properly. /var/db/dhclient.leases The DHCP client keeps a database of valid leases in this file, which is written as a log. &man.dhclient.leases.5; gives a slightly longer description. Further Reading The DHCP protocol is fully described in RFC 2131. An informational resource has also been set up at dhcp.org. Ceri Davies Written by
ceri@FreeBSD.org
Installing And Configuring A DHCP Server What this Section Covers This section provides information on how to configure a FreeBSD system to act as a DHCP server using the ISC (Internet Software Consortium) implementation of the DHCP suite. The server portion of the suite is not provided as part of FreeBSD, and so you will need to install the net/isc-dhcp3 port to provide this service. See for more information on using the ports collection. DHCP Server Installation DHCP installation In order to configure your FreeBSD system as a DHCP server, you will need to ensure that the &man.bpf.4; device is compiled into your kernel. To do this, add pseudo-device bpf to your kernel configuration file, and rebuild the kernel. For more information about building kernels, see . The bpf device is already part of the GENERIC kernel that is supplied with FreeBSD, so you do not need to create a custom kernel in order to get DHCP working. Those who are particularly security conscious should note that bpf is also the device that allows packet sniffers to work correctly (although such programs still need privileged access). bpf is required to use DHCP, but if you are very sensitive about security, you probably should not include bpf in your kernel purely because you expect to use DHCP at some point in the future. The next thing that you will need to do is edit the sample dhcpd.conf which was installed by the net/isc-dhcp3 port. By default, this will be /usr/local/etc/dhcpd.conf.sample, and you should copy this to /usr/local/etc/dhcpd.conf before proceeding to make changes. Configuring the DHCP Server DHCP dhcpd.conf dhcpd.conf is comprised of declarations regarding subnets and hosts, and is perhaps most easily explained using an example : option domain-name "example.com"; option domain-name-servers 192.168.4.100; option subnet-mask 255.255.255.0; default-lease-time 3600; max-lease-time 86400; ddns-update-style none; subnet 192.168.4.0 netmask 255.255.255.0 { range 192.168.4.129 192.168.4.254; option routers 192.168.4.1; } host mailhost { hardware ethernet 02:03:04:05:06:07; fixed-address mailhost.example.com; } This option specifies the domain that will be provided to clients as the default search domain. See &man.resolv.conf.5; for more information on what this means. This option specifies a comma separated list of DNS servers that the client should use. The netmask that will be provided to clients. A client may request a specific length of time that a lease will be valid. Otherwise the server will assign a lease with this expiry value (in seconds). This is the maximum length of time that the server will lease for. Should a client request a longer lease, a lease will be issued, although it will only be valid for max-lease-time seconds. This option specifies whether the DHCP server should attempt to update DNS when a lease is accepted or released. In the ISC implementation, this option is required. This denotes which IP addresses should be used in the pool reserved for allocating to clients. IP addresses between, and including, the ones stated are handed out to clients. Declares the default gateway that will be provided to clients. The hardware MAC address of a host (so that the DHCP server - can recognise a host when it makes a request). + can recognize a host when it makes a request). Specifies that the host should always be given the same IP address. Note that a hostname is OK here, since the DHCP server will resolve the hostname itself before returning the lease information. Once you have finished writing your dhcpd.conf, you can proceed to start the server by issuing the following command: &prompt.root; /usr/local/etc/rc.d/isc-dhcpd.sh start Should you need to make changes to the configuration of your server in the future, it is important to note that sending a SIGHUP signal to dhcpd does not result in the configuration being reloaded, as it does with most daemons. You will need to send a SIGTERM signal to stop the process, and then restart it using the command above. Files DHCP configuration files /usr/local/sbin/dhcpd dhcpd is statically linked and resides in /usr/local/sbin. The dhcpd(8) manual page installed with the port gives more information about dhcpd. /usr/local/etc/dhcpd.conf dhcpd requires a configuration file, /usr/local/etc/dhcpd.conf before it will start providing service to clients. This file needs to contain all the information that should be provided to clients that are being serviced, along with information regarding the operation of the server. This configuration file is described by the dhcpd.conf(5) manual page installed by the port. /var/db/dhcpd.leases The DHCP server keeps a database of leases it has issued in this file, which is written as a log. The manual page dhcpd.leases(5), installed by the port gives a slightly longer description. /usr/local/sbin/dhcrelay dhcrelay is used in advanced environments where one DHCP server forwards a request from a client to another DHCP server on a separate network. The dhcrelay(8) manual page provided with the port contains more detail.
Chern Lee Contributed by DNS Overview BIND FreeBSD utilizes, by default, a version of BIND (Berkeley Internet Name Domain), which is the most common implementation of the DNS protocol. DNS is the protocol through which names are mapped to IP addresses, and vice versa. For example, a query for www.FreeBSD.org will receive a reply with the IP address of The FreeBSD Project's web server, whereas, a query for ftp.FreeBSD.org will return the IP address of the corresponding FTP machine. Likewise, the opposite can happen. A query for an IP address can resolve its hostname. It is not necessary to run a name server to perform DNS lookups on a system. DNS DNS is coordinated across the Internet through a somewhat complex system of authoritative root name servers, and other smaller-scale name servers who host and cache individual domain information. This document refers to BIND 8.x, as it is the stable version used in FreeBSD. BIND 9.x in FreeBSD can be installed through the net/bind9 port. RFC1034 and RFC1035 dictate the DNS protocol. Currently, BIND is maintained by the Internet Software Consortium (www.isc.org) Terminology To understand this document, some terms related to DNS must be understood. Term Definition forward DNS mapping of hostnames to IP addresses origin refers to the domain covered for the particular zone file named, bind, name server common names for the BIND name server package within FreeBSD resolver resolver a system process through which a machine queries a name server for zone information reverse DNS reverse DNS the opposite of forward DNS, mapping of IP addresses to hostnames root zone root zone literally, a ., refers to the root, or beginning zone. All zones fall under this, as do all files in fall under the root directory. It is the beginning of the Internet zone hierarchy. zone Each individual domain, subdomain, or area dictated by DNS zones examples Examples of zones: . is the root zone org. is a zone under the root zone example.org is a zone under the org. zone foo.example.org. is a subdomain, a zone under the example.org. zone 1.2.3.in-addr.arpa is a zone referencing all IP addresses which fall under the 3.2.1.* IP space. As one can see, the more specific part of a hostname appears to its left. For example, example.org. is more specific than org., as org. is more specific than the root zone. The layout of each part of a hostname is much like a filesystem: the /dev directory falls within the root, and so on. Reasons to Run a Name Server Name servers usually come in two forms: an authoritative name server, and a caching name server. An authoritative name server is needed when: one wants to serve DNS information to the world, replying authoritatively to queries. a domain, such as example.org, is registered and IP addresses need to be assigned to hostnames under it. an IP address block requires reverse DNS entries (IP to hostname). a backup name server, called a slave, must reply to queries when the primary is down or inaccessible. A caching name server is needed when: a local DNS server may cache and respond more quickly than querying an outside name server. a reduction in overall network traffic is desired (DNS traffic has been measured to account for 5% or more of total Internet traffic). When one queries for www.FreeBSD.org, the resolver usually queries the uplink ISP's name server, and retrieves the reply. With a local, caching DNS server, the query only has to be made once to the outside world by the caching DNS server. Every additional query will not have to look to the outside of the local network, since the information is cached locally. How It Works In FreeBSD, the BIND daemon is called named for obvious reasons. File Description named the BIND daemon ndc name daemon control program /etc/namedb directory where BIND zone information resides /etc/namedb/named.conf daemon configuration file Zone files are usually contained within the /etc/namedb directory, and contain the DNS zone information served by the name server. Starting BIND BIND starting Since BIND is installed by default, configuring it all is relatively simple. To ensure the named daemon is started at boot, put the following modifications in /etc/rc.conf: named_enable="YES" To start the daemon manually (after configuring it) &prompt.root; ndc start Configuration Files BIND configuration files make-localhost Be sure to: &prompt.root; cd /etc/namedb &prompt.root; sh make-localhost to properly create the local reverse DNS zone file in /etc/namedb/localhost.rev. <filename>/etc/namedb/named.conf</filename> // $FreeBSD$ // // Refer to the named(8) manual page for details. If you are ever going // to setup a primary server, make sure you've understood the hairy // details of how DNS is working. Even with simple mistakes, you can // break connectivity for affected parties, or cause huge amount of // useless Internet traffic. options { directory "/etc/namedb"; // In addition to the "forwarders" clause, you can force your name // server to never initiate queries of its own, but always ask its // forwarders only, by enabling the following line: // // forward only; // If you've got a DNS server around at your upstream provider, enter // its IP address here, and enable the line below. This will make you // benefit from its cache, thus reduce overall DNS traffic in the Internet. /* forwarders { 127.0.0.1; }; */ Just as the comment says, to benefit from an uplink's cache, forwarders can be enabled here. Under normal circumstances, a name server will recursively query the Internet looking at certain name servers until it finds the answer it is looking for. Having this enabled will have it query the uplink's name server (or name server provided) first, taking advantage of its cache. If the uplink name server in question is a heavily trafficked, fast name server, enabling this may be worthwhile. 127.0.0.1 will not work here. Change this IP address to a name server at your uplink. /* * If there is a firewall between you and name servers you want * to talk to, you might need to uncomment the query-source * directive below. Previous versions of BIND always asked * questions using port 53, but BIND 8.1 uses an unprivileged * port by default. */ // query-source address * port 53; /* * If running in a sandbox, you may have to specify a different * location for the dumpfile. */ // dump-file "s/named_dump.db"; }; // Note: the following will be supported in a future release. /* host { any; } { topology { 127.0.0.0/8; }; }; */ // Setting up secondaries is way easier and the rough picture for this // is explained below. // // If you enable a local name server, don't forget to enter 127.0.0.1 // into your /etc/resolv.conf so this server will be queried first. // Also, make sure to enable it in /etc/rc.conf. zone "." { type hint; file "named.root"; }; zone "0.0.127.IN-ADDR.ARPA" { type master; file "localhost.rev"; }; zone "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.IP6.INT" { type master; file "localhost.rev"; }; // NB: Do not use the IP addresses below, they are faked, and only // serve demonstration/documentation purposes! // // Example secondary config entries. It can be convenient to become // a secondary at least for the zone where your own domain is in. Ask // your network administrator for the IP address of the responsible // primary. // // Never forget to include the reverse lookup (IN-ADDR.ARPA) zone! // (This is the first bytes of the respective IP address, in reverse // order, with ".IN-ADDR.ARPA" appended.) // // Before starting to setup a primary zone, better make sure you fully // understand how DNS and BIND works, however. There are sometimes // unobvious pitfalls. Setting up a secondary is comparably simpler. // // NB: Don't blindly enable the examples below. :-) Use actual names // and addresses instead. // // NOTE!!! FreeBSD runs bind in a sandbox (see named_flags in rc.conf). // The directory containing the secondary zones must be write accessible // to bind. The following sequence is suggested: // // mkdir /etc/namedb/s // chown bind:bind /etc/namedb/s // chmod 750 /etc/namedb/s For more information on running BIND in a sandbox, see Running named in a sandbox. /* zone "example.com" { type slave; file "s/example.com.bak"; masters { 192.168.1.1; }; }; zone "0.168.192.in-addr.arpa" { type slave; file "s/0.168.192.in-addr.arpa.bak"; masters { 192.168.1.1; }; }; */ In named.conf, these are examples of slave entries for a forward and reverse zone. For each new zone served, a new zone entry must be added to named.conf For example, the simplest zone entry for example.org can look like: zone "example.org" { type master; file "example.org"; }; The zone is a master, as indicated by the statement, holding its zone information in /etc/namedb/example.org indicated by the statement. zone "example.org" { type slave; file "example.org"; }; In the slave case, the zone information is transferred from the master name server for the particular zone, and saved in the file specified. If and when the master server dies or is unreachable, the slave name server will have the transferred zone information and will be able to serve it. Zone Files An example master zone file for example.org (existing within /etc/namedb/example.org) is as follows: $TTL 3600 example.org. IN SOA ns1.example.org. admin.example.org. ( 5 ; Serial 10800 ; Refresh 3600 ; Retry 604800 ; Expire 86400 ) ; Minimum TTL ; DNS Servers @ IN NS ns1.example.org. @ IN NS ns2.example.org. ; Machine Names localhost IN A 127.0.0.1 ns1 IN A 3.2.1.2 ns2 IN A 3.2.1.3 mail IN A 3.2.1.10 @ IN A 3.2.1.30 ; Aliases www IN CNAME @ ; MX Record @ IN MX 10 mail.example.org. Note that every hostname ending in a . is an exact hostname, whereas everything without a trailing . is referenced to the origin. For example, www is translated into www + origin. In our fictitious zone file, our origin is example.org., so www would translate to www.example.org. The format of a zone file follows: recordname IN recordtype value DNS records The most commonly used DNS records: SOA start of zone authority NS an authoritative name server A A host address CNAME the canonical name for an alias MX mail exchanger PTR a domain name pointer (used in reverse DNS) example.org. IN SOA ns1.example.org. admin.example.org. ( 5 ; Serial 10800 ; Refresh after 3 hours 3600 ; Retry after 1 hour 604800 ; Expire after 1 week 86400 ) ; Minimum TTL of 1 day example.org. the domain name, also the origin for this zone file. ns1.example.org. the primary/authoritative name server for this zone admin.example.org. the responsible person for this zone, email address with @ replaced. (admin@example.org becomes admin.example.org) 5 the serial number of the file. this must be incremented each time the zone file is modified. Nowadays, many admins prefer a yyyymmddrr format for the serial number. 2001041002 would mean last modified 04/10/2001, the latter 02 being the second time the zone file has been modified this day. The serial number is important as it alerts slave name servers for a zone when it is updated. @ IN NS ns1.example.org. This is an NS entry. Every name server that is going to reply authoritatively for the zone must have one of these entries. The @ as seen here could have been example.org. The @ translates to the origin. localhost IN A 127.0.0.1 ns1 IN A 3.2.1.2 ns2 IN A 3.2.1.3 mail IN A 3.2.1.10 @ IN A 3.2.1.30 The A record indicates machine names. As seen above, ns1.example.org would resolve to 3.2.1.2. Again, the origin symbol, @, is used here, thus meaning example.org would resolve to 3.2.1.30. www IN CNAME @ The canonical name record is usually used for giving aliases to a machine. In the example, www is aliased to the machine addressed to the origin, or example.org (3.2.1.30). CNAMEs can be used to provide alias hostnames, or round robin one hostname among multiple machines. @ IN MX 10 mail.example.org. The MX record indicates which mail servers are responsible for handling incoming mail for the zone. mail.example.org is the hostname of the mail server, and 10 being the priority of that mail server. One can have several mail servers, with priorities of 3, 2, 1. A mail server attempting to deliver to example.org would first try the highest priority MX, then the second highest, etc, until the mail can be properly delivered. For in-addr.arpa zone files (reverse DNS), the same format is used, except with PTR entries instead of A or CNAME. $TTL 3600 1.2.3.in-addr.arpa. IN SOA ns1.example.org. admin.example.org. ( 5 ; Serial 10800 ; Refresh 3600 ; Retry 604800 ; Expire 3600 ) ; Minimum @ IN NS ns1.example.org. @ IN NS ns2.example.org. 2 IN PTR ns1.example.org. 3 IN PTR ns2.example.org. 10 IN PTR mail.example.org. 30 IN PTR example.org. This file gives the proper IP address to hostname mappings of our above fictitious domain. Caching Name Server BIND caching name server A caching name server is a name server that is not authoritative for any zones. It simply asks queries of its own, and remembers them for later use. To set one up, just configure the name server as usual, omitting any inclusions of zones. Ceri Davies Contributed by Running named in a Sandbox BIND running in a sandbox chroot For added security you may want to run &man.named.8; as an unprivileged user, and configure it to &man.chroot.8; into a sandbox directory. This makes everything outside of the sandbox inaccessible to the named daemon. Should named be compromised, this will help to reduce the damage that can be caused. By default, FreeBSD has a user and a group called bind, intended for this use. Various people would recommend that instead of configuring named to chroot, you should run named inside a &man.jail.8;. This section does not attempt to cover this situation. Since named will not be able to access anything outside of the sandbox (such as shared libraries, log sockets, and so on), there are a number of steps that need to be followed in order to allow named to function correctly. In the following checklist, it is assumed that the path to the sandbox is /etc/namedb and that you have made no prior modifications to the contents of this directory. Perform the following steps as root. Create all directories that named expects to see: &prompt.root; cd /etc/namedb &prompt.root; mkdir -p bin dev etc var/tmp var/run master slave &prompt.root; chown bind:bind slave var/* named only needs write access to these directories, so that is all we give it. Rearrange and create basic zone and configuration files: &prompt.root; cp /etc/localtime etc &prompt.root; mv named.conf etc && ln -sf etc/named.conf &prompt.root; mv named.root master &prompt.root; sh make-localhost && mv localhost.rev localhost-v6.rev master &prompt.root; cat > master/named.localhost $ORIGIN localhost. $TTL 6h @ IN SOA localhost. postmaster.localhost. ( 1 ; serial 3600 ; refresh 1800 ; retry 604800 ; expiration 3600 ) ; minimum IN NS localhost. IN A 127.0.0.1 ^D This allows named to log the correct time to &man.syslogd.8; Build a statically linked copy of named-xfer, and copy it into the sandbox: &prompt.root; cd /usr/src/lib/libisc &prompt.root; make cleandir && make cleandir && make depend && make all &prompt.root; cd /usr/src/lib/libbind &prompt.root; make cleandir && make cleandir && make depend && make all &prompt.root; cd /usr/src/libexec/named-xfer &prompt.root; make cleandir && make cleandir && make depend && make NOSHARED=yes all &prompt.root; cp named-xfer /etc/namedb/bin && chmod 555 /etc/namedb/bin/named-xfer After your statically linked named-xfer is installed some cleaning up is required, to avoid leaving stale copies of libraries or programs in your source tree: &prompt.root; cd /usr/src/lib/libisc &prompt.root; make cleandir &prompt.root; cd /usr/src/lib/libbind &prompt.root; make cleandir &prompt.root; cd /usr/src/libexec/named-xfer &prompt.root; make cleandir This step has been reported to fail occasionally. If this happens to you, then issue the command: &prompt.root; cd /usr/src && make cleandir && make cleandir and delete your /usr/obj tree: &prompt.root; rm -fr /usr/obj && mkdir /usr/obj This will clean out any cruft from your source tree, and retrying the steps above should then work. Make a dev/null that named can see and write to: &prompt.root; cd /etc/namedb/dev && mknod null c 2 2 &prompt.root; chmod 666 null Symlink /var/run/ndc to /etc/namedb/var/run/ndc: &prompt.root; ln -sf /etc/namedb/var/run/ndc /var/run/ndc This simply avoids having to specify the option to &man.ndc.8; every time you run it. Since the contents of /var/run are deleted on boot, if this is something that you find useful you may wish to add this command to root's crontab, making use of the option. See &man.crontab.5; for more information regarding this. Configure &man.syslogd.8; to create an extra log socket that named can write to. To do this, add -l /etc/namedb/dev/log to the syslogd_flags variable in /etc/rc.conf. Arrange to have named start and chroot itself to the sandbox by adding the following to /etc/rc.conf: named_enable="YES" named_flags="-u bind -g bind -t /etc/namedb /etc/named.conf" Note that the configuration file /etc/named.conf is denoted by a full pathname relative to the sandbox, i.e. in the line above, the file referred to is actually /etc/namedb/etc/named.conf. The next step is to edit /etc/namedb/etc/named.conf so that named knows which zones to load and where to find them on the disk. There follows a commented example (anything not specifically commented here is no different from the setup for a DNS server not running in a sandbox): options { directory "/"; named-xfer "/bin/named-xfer"; version ""; // Don't reveal BIND version query-source address * port 53; }; // ndc control socket controls { unix "/var/run/ndc" perm 0600 owner 0 group 0; }; // Zones follow: zone "localhost" IN { type master; file "master/named.localhost"; allow-transfer { localhost; }; notify no; }; zone "0.0.127.in-addr.arpa" IN { type master; file "master/localhost.rev"; allow-transfer { localhost; }; notify no; }; zone "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.int" { type master; file "master/localhost-v6.rev"; allow-transfer { localhost; }; notify no; }; zone "." IN { type hint; file "master/named.root"; }; zone "private.example.net" in { type master; file "master/private.example.net.db"; allow-transfer { 192.168.10.0/24; }; }; zone "10.168.192.in-addr.arpa" in { type slave; masters { 192.168.10.2; }; file "slave/192.168.10.db"; }; The directory statement is specified as /, since all files that named needs are within this directory (recall that this is equivalent to a normal user's /etc/namedb. Specifies the full path to the named-xfer binary (from named's frame of reference). This is necessary since named is compiled to look for named-xfer in /usr/libexec by default. Specifies the filename (relative to the directory statement above) where named can find the zonefile for this zone. Specifies the filename (relative to the directory statement above) where named should write a copy of the zonefile for this zone after successfully transferring it from the master server. This is why we needed to change the ownership of the directory slave to bind in the setup stages above. After completing the steps above, either reboot your server or restart &man.syslogd.8; and start &man.named.8;, making sure to use the new options specified in syslogd_flags and named_flags. You should now be running a sandboxed copy of named! Security Although BIND is the most common implementation of DNS, there is always the issue of security. Possible and exploitable security holes are sometimes found. It is a good idea to subscribe to CERT and freebsd-security-notifications to stay up to date with the current Internet and FreeBSD security issues. If a problem arises, keeping sources up to date and having a fresh build of named would not hurt. Further Reading BIND/named manual pages: &man.ndc.8; &man.named.8; &man.named.conf.5; Official ISC Bind Page BIND FAQ O'Reilly DNS and BIND 4th Edition RFC1034 - Domain Names - Concepts and Facilities RFC1035 - Domain Names - Implementation and Specification Tom Hukins Contributed by NTP NTP Overview Over time, a computer's clock is prone to drift. As time passes, the computer's clock becomes less accurate. NTP (Network Time Protocol) is one way to ensure your clock is right. Many Internet services rely on, or greatly benefit from, computers' clocks being accurate. For example, a Web server may receive requests to send a file if it has modified since a certain time. Services such as &man.cron.8; run commands at a given time. If the clock is inaccurate, these commands may not run when expected. NTP ntpd FreeBSD ships with the &man.ntpd.8; NTP server which can be used to query other NTP servers to set the clock on your machine or provide time services to others. Choosing Appropriate NTP Servers NTP choosing servers In order to synchronize your clock, you will need to find one or more NTP servers to use. Your network administrator or ISP may have setup an NTP server for this purpose—check their documentation to see if this is the case. There is a list of publicly accessible NTP servers which you can use to find an NTP server near to you. Make sure you are aware of the policy for any servers you choose, and ask for permission if required. Choosing several unconnected NTP servers is a good idea in case one of the servers you are using becomes unreachable or its clock is unreliable. &man.ntpd.8; uses the responses it receives from other servers intelligently—it will favor unreliable servers less than reliable ones. Configuring Your Machine NTP configuration Basic Configuration ntpdate If you only wish to synchronize your clock when the machine boots up, you can use &man.ntpdate.8;. This may be appropriate for some desktop machines which are frequently rebooted and only require infrequent synchronization, but most machines should run &man.ntpd.8;. Using &man.ntpdate.8; at boot time is also a good idea for machines that run &man.ntpd.8;. &man.ntpd.8; changes the clock gradually, whereas &man.ntpdate.8; sets the clock, no matter how great the difference between a machine's current clock setting and the correct time. To enable &man.ntpdate.8; at boot time, add ntpdate_enable="YES" to /etc/rc.conf. You will also need to specify all servers you wish to synchronize with and any flags to be passed to &man.ntpdate.8; in ntpdate_flags. NTP ntp.conf General Configuration NTP is configured by the /etc/ntp.conf file in the format described in &man.ntp.conf.5;. Here is a simple example: server ntplocal.example.com prefer server timeserver.example.org server ntp2a.example.net driftfile /var/db/ntp.drift The server option specifies which servers are to be used, with one server listed on each line. If a server is specified with the prefer argument, as with ntplocal.example.com, that server is preferred over other servers. A response from a preferred server will be discarded if it differs significantly from other servers' responses, otherwise it will be used without any consideration to other responses. The prefer argument is normally used for NTP servers that are known to be highly accurate, such as those with special time monitoring hardware. The driftfile option specifies which file is used to store the system clock's frequency offset. &man.ntpd.8; uses this to automatically compensate for the clock's natural drift, allowing it to maintain a reasonably correct setting even if it is cut off from all external time sources for a period of time. The driftfile option specifies which file is used to store information about previous responses from the NTP servers you are using. This file contains internal information for NTP. It should not be modified by any other process. Controlling Access to Your Server By default, your NTP server will be accessible to all hosts on the Internet. The restrict option in &man.ntp.conf.5; allows you to control which machines can access your server. If you want to deny all machines from accessing your NTP server, add the line restrict default ignore to /etc/ntp.conf. If you only want to allow machines within your own network to synchronize their clocks with your server, but ensure they are not allowed to configure the server or used as peers to synchronize against, add restrict 192.168.1.0 mask 255.255.255.0 notrust nomodify notrap instead, where 192.168.1.0 is an IP address on your network and 255.255.255.0 is your network's netmask. /etc/ntp.conf can contain multiple restrict options. For more details, see the Access Control Support subsection of &man.ntp.conf.5;. Running the NTP Server To ensure the NTP server is started at boot time, add the line xntpd_enable="YES" to /etc/rc.conf. If you wish to pass additional flags to &man.ntpd.8; edit the xntpd_flags parameter in /etc/rc.conf. To start the server without rebooting your machine, run ntpd being sure to specify any additional parameters from xntpd_flags in /etc/rc.conf. For example: &prompt.root; ntpd -p /var/run/ntpd.pid Using &man.ntpd.8; with a temporary Internet connection ntpd does not need a permanent connection to the Internet to function properly. However, if you have a temporary connection that is configured to dial out on demand, it is a good idea to prevent NTP traffic from triggering a dial out or keeping the connection alive. If you are using user PPP, you can use filter directives in /etc/ppp/ppp.conf. For example: set filter dial 0 deny udp src eq 123 # Prevent NTP traffic from initiating dial out set filter dial 1 permit 0 0 set filter alive 0 deny udp src eq 123 # Prevent incoming NTP traffic from keeping the connection open set filter alive 1 deny udp dst eq 123 # Prevent outgoing NTP traffic from keeping the connection open set filter alive 2 permit 0/0 0/0 For more details see the PACKET FILTERING section in &man.ppp.8; and the examples in /usr/share/examples/ppp/. Some Internet access providers block low-numbered ports, preventing NTP from functioning since replies never reach your machine. Further Information Documentation for the NTP server can be found in /usr/share/doc/ntp/ in HTML format. Chern Lee Contributed by Network Address Translation Overview natd FreeBSD's Network Address Translation daemon, commonly known as &man.natd.8; is a daemon that accepts incoming raw IP packets, changes the source to the local machine and re-injects these packets back into the outgoing IP packet stream. natd does this by changing the source IP address and port such that when data is received back, it is able to determine the original location of the data and forward it back to its original requester. Internet connection sharing IP masquerading The most common use of NAT is to perform what is commonly known as Internet Connection Sharing. Setup Due to the diminishing IP space in IPv4, and the increased number of users on high-speed consumer lines such as cable or DSL, people are increasingly in need of an Internet Connection Sharing solution. The ability to connect several computers online through one connection and IP address makes &man.natd.8; a reasonable choice. Most commonly, a user has a machine connected to a cable or DSL line with one IP address and wishes to use this one connected computer to provide Internet access to several more over a LAN. To do this, the FreeBSD machine on the Internet must act as a gateway. This gateway machine must have two NICs--one for connecting to the Internet router, the other connecting to a LAN. All the machines on the LAN are connected through a hub or switch. _______ __________ ________ | | | | | | | Hub |-----| Client B |-----| Router |----- Internet |_______| |__________| |________| | ____|_____ | | | Client A | |__________| Network Layout A setup like this is commonly used to share an Internet connection. One of the LAN machines is connected to the Internet. The rest of the machines access the Internet through that gateway machine. kernel configuration Configuration The following options must be in the kernel configuration file: options IPFIREWALL options IPDIVERT Additionally, at choice, the following may also be suitable: options IPFIREWALL_DEFAULT_TO_ACCEPT options IPFIREWALL_VERBOSE The following must be in /etc/rc.conf: gateway_enable="YES" firewall_enable="YES" firewall_type="OPEN" natd_enable="YES" natd_interface="fxp0" natd_flags="" gateway_enable="YES" Sets up the machine to act as a gateway. Running sysctl net.inet.ip.forwarding=1 would have the same effect. firewall_enable="YES" Enables the firewall rules in /etc/rc.firewall at boot. firewall_type="OPEN" This specifies a predefined firewall ruleset that allows anything in. See /etc/rc.firewall for additional types. natd_interface="fxp0" Indicates which interface to forward packets through (the interface connected to the Internet). natd_flags="" Any additional configuration options passed to &man.natd.8; on boot. Having the previous options defined in /etc/rc.conf would run natd -interface fxp0 at boot. This can also be run manually. Each machine and interface behind the LAN should be assigned IP address numbers in the private network space as defined by RFC 1918 and have a default gateway of the natd machine's internal IP address. For example, client a and b behind the LAN have IP addresses of 192.168.0.2 and 192.168.0.3, while the natd machine's LAN interface has an IP address of 192.168.0.1. Client a and b's default gateway must be set to that of the natd machine, 192.168.0.1. The natd machine's external, or Internet interface does not require any special modification for natd to work. Port Redirection The drawback with natd is that the LAN clients are not accessible from the Internet. Clients on the LAN can make outgoing connections to the world but cannot receive incoming ones. This presents a problem if trying to run Internet services on one of the LAN client machines. A simple way around this is to redirect selected Internet ports on the natd machine to a LAN client. For example, an IRC server runs on Client A, and a web server runs on Client B. For this to work properly, connections received on ports 6667 (IRC) and 80 (web) must be redirected to the respective machines. The -redirect_port must be passed to &man.natd.8; with the proper options. The syntax is as follows: -redirect_port proto targetIP:targetPORT[-targetPORT] [aliasIP:]aliasPORT[-aliasPORT] [remoteIP[:remotePORT[-remotePORT]]] In the above example, the argument should be: -redirect_port tcp 192.168.0.2:6667 6667 -redirect_port tcp 192.168.0.3:80 80 This will redirect the proper tcp ports to the LAN client machines. The -redirect_port argument can be used to indicate port ranges over individual ports. For example, tcp 192.168.0.2:2000-3000 2000-3000 would redirect all connections received on ports 2000 to 3000 to ports 2000 to 3000 on Client A. These options can be used when directly running &man.natd.8; or placed within the natd_flags="" option in /etc/rc.conf. For further configuration options, consult &man.natd.8; Address Redirection address redirection Address redirection is useful if several IP addresses are available, yet they must be on one machine. With this, &man.natd.8; can assign each LAN client its own external IP address. &man.natd.8; then rewrites outgoing packets from the LAN clients with the proper external IP address and redirects all traffic incoming on that particular IP address back to the specific LAN client. This is also known as static NAT. For example, the IP addresses 128.1.1.1, 128.1.1.2, and 128.1.1.3 belong to the natd gateway machine. 128.1.1.1 can be used as the natd gateway machine's external IP address, while 128.1.1.2 and 128.1.1.3 are forwarded back to LAN clients A and B. The -redirect_address syntax is as follows: localIP The internal IP address of the LAN client. publicIP The external IP address corresponding to the LAN client. In the example, this argument would read: Like -redirect_port, these arguments are also placed within natd_flags of /etc/rc.conf. With address redirection, there is no need for port redirection since all data received on a particular IP address is redirected. The external IP addresses on the natd machine must be active and aliased to the external interface. Look at &man.rc.conf.5; to do so. Chern Lee Contributed by inetd <quote>Super-Server</quote> Overview &man.inetd.8; is referred to as the Internet Super-Server because it manages connections for several daemons. Programs that provide network service are commonly known as daemons. inetd serves as a managing server for other daemons. When a connection is received by inetd, it determines which daemon the connection is destined for, spawns the particular daemon and delegates the socket to it. Running one instance of inetd reduces the overall system load as compared to running each daemon individually in stand-alone mode. Primarily, inetd is used to spawn other daemons, but several trivial protocols are handled directly, such as chargen, auth, and daytime. This section will cover the basics in configuring inetd through its command-line options and its configuration file, /etc/inetd.conf. Settings inetd is initialized through the /etc/rc.conf system. The inetd_enable option is set to NO by default, but is often times turned on by sysinstall with the medium security profile. Placing: inetd_enable="YES" or inetd_enable="NO" into /etc/rc.conf can enable or disable inetd starting at boot time. Additionally, different command-line options can be passed to inetd via the inetd_flags option. Command-Line Options inetd synopsis: -d Turn on debugging. -l Turn on logging of successful connections. -w Turn on TCP Wrapping for external services (on by default). -W Turn on TCP Wrapping for internal services which are built into inetd (on by default). -c maximum Specify the default maximum number of simultaneous invocations of each service; the default is unlimited. May be overridden on a per-service basis with the parameter. -C rate Specify the default maximum number of times a service can be invoked from a single IP address in one minute; the default is unlimited. May be overridden on a per-service basis with the parameter. -R rate Specify the maximum number of times a service can be invoked in one minute; the default is 256. A rate of 0 allows an unlimited number of invocations. -a Specify one specific IP address to bind to. Alternatively, a hostname can be specified, in which case the IPv4 or IPv6 address which corresponds to that hostname is used. Usually a hostname is specified when inetd is run inside a &man.jail.8;, in which case the hostname corresponds to the &man.jail.8; environment. When hostname specification is used and both IPv4 and IPv6 bindings are desired, one entry with the appropriate protocol type for each binding is required for each service in /etc/inetd.conf. For example, a TCP-based service would need two entries, one using tcp4 for the protocol and the other using tcp6. -p Specify an alternate file in which to store the process ID. These options can be passed to inetd using the inetd_flags option in /etc/rc.conf. By default, inetd_flags is set to -wW, which turns on TCP wrapping for inetd's internal and external services. For novice users, these parameters usually do not need to be modified or even entered in /etc/rc.conf. An external service is a daemon outside of inetd, which is invoked when a connection is received for it. On the other hand, an internal service is one that inetd has the facility of offering within itself. <filename>inetd.conf</filename> Configuration of inetd is controlled through the /etc/inetd.conf file. When a modification is made to /etc/inetd.conf, inetd can be forced to re-read its configuration file by sending a HangUP signal to the inetd process as shown: Sending <application>inetd</application> a HangUP Signal &prompt.root; kill -HUP `cat /var/run/inetd.pid` Each line of the configuration file specifies an individual daemon. Comments in the file are preceded by a #. The format of /etc/inetd.conf is as follows: service-name socket-type protocol {wait|nowait}[/max-child[/max-connections-per-ip-per-minute]] user[:group][/login-class] server-program server-program-arguments An example entry for the ftpd daemon using IPv4: ftp stream tcp nowait root /usr/libexec/ftpd ftpd -l service-name This is the service name of the particular daemon. It must correspond to a service listed in /etc/services. This determines which port inetd must listen to. If a new service is being created, it must be placed in /etc/services first. socket-type Either stream, dgram, raw, or seqpacket. stream must be used for connection-based, TCP daemons, while dgram is used for daemons utilizing the UDP transport protocol. protocol One of the following: Protocol Explanation tcp, tcp4 TCP IPv4 udp, udp4 UDP IPv4 tcp6 TCP IPv6 udp6 UDP IPv6 tcp46 Both TCP IPv4 and v6 udp46 Both UDP IPv4 and v6 {wait|nowait}[/max-child[/max-connections-per-ip-per-minute]] indicates whether the daemon invoked from inetd is able to handle its own socket or not. socket types must use the wait option, while stream socket daemons, which are usually multi-threaded, should use . usually hands off multiple sockets to a single daemon, while spawns a child daemon for each new socket. The maximum number of child daemons inetd may spawn can be set using the option. If a limit of ten instances of a particular daemon is needed, a /10 would be placed after . In addition to , another option limiting the maximum connections from a single place to a particular daemon can be enabled. does just this. A value of ten here would limit any particular IP address connecting to a particular service to ten attempts per minute. This is useful to prevent intentional or unintentional resource consumption and Denial of Service (DoS) attacks to a machine. In this field, or is mandatory. and are optional. A stream-type multi-threaded daemon without any or limits would simply be: nowait The same daemon with a maximum limit of ten daemons would read: nowait/10 Additionally, the same setup with a limit of twenty connections per IP address per minute and a maximum total limit of ten child daemons would read: nowait/10/20 These options are all utilized by the default settings of the fingerd daemon, as seen here: finger stream tcp nowait/3/10 nobody /usr/libexec/fingerd fingerd -s user The user is the username that the particular daemon should run as. Most commonly, daemons run as the root user. For security purposes, it is common to find some servers running as the daemon user, or the least privileged nobody user. server-program The full path of the daemon to be executed when a connection is received. If the daemon is a service provided by inetd internally, then should be used. server-program-arguments This works in conjunction with by specifying the arguments, starting with argv[0], passed to the daemon on invocation. If mydaemon -d is the command line, mydaemon -d would be the value of . Again, if the daemon is an internal service, use here. Security Depending on the security profile chosen at install, many of inetd's daemons may be enabled by default. If there is no apparent need for a particular daemon, disable it! Place a # in front of the daemon in question, and send a hangup signal to inetd. Some daemons, such as fingerd, may not be desired at all because they provide an attacker with too much information. Some daemons are not security-conscious and have long, or non-existent timeouts for connection attempts. This allows an attacker to slowly send connections to a particular daemon, thus saturating available resources. It may be a good idea to place and limitations on certain daemons. By default, TCP wrapping is turned on. Consult the &man.hosts.access.5; manual page for more information on placing TCP restrictions on various inetd invoked daemons. Miscellaneous daytime, time, echo, discard, chargen, and auth are all internally provided services of inetd. The auth service provides identity (ident, identd) network services, and is configurable to a certain degree. Consult the &man.inetd.8; manual page for more in-depth information. Parallel Line IP (PLIP) PLIP Parallel Line IP PLIP lets us run TCP/IP between parallel ports. It is useful on machines without network cards, or to install on laptops. In this section, we will discuss: Creating a parallel (laplink) cable. Connecting two computers with PLIP. Creating a Parallel Cable You can purchase a parallel cable at most computer supply stores. If you cannot do that, or you just want to know how it is done, the following table shows how to make one out of a normal parallel printer cable. Wiring a parallel cable for networking A-name A-End B-End Descr. Post/Bit DATA0 -ERROR 2 15 15 2 Data 0/0x01 1/0x08 DATA1 +SLCT 3 13 13 3 Data 0/0x02 1/0x10 DATA2 +PE 4 12 12 4 Data 0/0x04 1/0x20 DATA3 -ACK 5 10 10 5 Strobe 0/0x08 1/0x40 DATA4 BUSY 6 11 11 6 Data 0/0x10 1/0x80 GND 18-25 18-25 GND -
Setting up PLIP Get a laplink cable. Confirm that both computers have a kernel with &man.lpt.4; driver support. &prompt.root; grep lp /var/run/dmesg.boot lpt0 at 0x378-0x37f irq 7 on isa lpt0: Interrupt-driven lp0: TCP/IP capable interface Plug in the laplink cable into the parallel interface on both computers. Configure the network interface parameters for lp0 on both sites as root. For example, if you want connect the host host1 with host2: host1 <-----> host2 IP Address 10.0.0.1 10.0.0.2 Configure the interface on host1 by doing: &prompt.root; ifconfig lp0 10.0.0.1 10.0.0.2 Configure the interface on host2 by doing: &prompt.root; ifconfig lp0 10.0.0.2 10.0.0.1 You now should have a working connection. Please read the manual pages &man.lp.4; and &man.lpt.4; for more details. You should also add both hosts to /etc/hosts: 127.0.0.1 localhost.my.domain localhost 10.0.0.1 host1.my.domain host1 10.0.0.2 host2.my.domain To confirm the connection works, go to each host and ping the other. For example, on host1: &prompt.root; ifconfig lp0 lp0: flags=8851<UP,POINTOPOINT,RUNNING,SIMPLEX,MULTICAST> mtu 1500 inet 10.0.0.1 --> 10.0.0.2 netmask 0xff000000 &prompt.root; netstat -r Routing tables Internet: Destination Gateway Flags Refs Use Netif Expire host2 host1 UH 4 127592 lp0 &prompt.root; ping -c 4 host2 PING host2 (10.0.0.2): 56 data bytes 64 bytes from 10.0.0.2: icmp_seq=0 ttl=255 time=2.774 ms 64 bytes from 10.0.0.2: icmp_seq=1 ttl=255 time=2.530 ms 64 bytes from 10.0.0.2: icmp_seq=2 ttl=255 time=2.556 ms 64 bytes from 10.0.0.2: icmp_seq=3 ttl=255 time=2.714 ms --- host2 ping statistics --- 4 packets transmitted, 4 packets received, 0% packet loss round-trip min/avg/max/stddev = 2.530/2.643/2.774/0.103 ms
Aaron Kaplan Originally Written by Tom Rhodes Restructured and Added by IPv6 IPv6 (also know as IPng IP next generation) is the new version of the well known IP protocol (also know as IPv4). Like the other current *BSD systems, FreeBSD includes the KAME IPv6 reference implementation. So your FreeBSD system comes with all you will need to experiment with IPv6. This section focuses on getting IPv6 configured and running. In the early 1990s, people became aware of the rapidly diminishing address space of IPv4. Given the expansion rate of the Internet there were two major concerns: Running out of addresses. Today this is not so much of a concern anymore since private address spaces (10.0.0.0/8, 192.168.0.0/24, etc.) and Network Address Translation (NAT) are being employed. Router table entries were getting too large. This is still a concern today. IPv6 deals with these and many other issues: 128 bit address space. In other words theoretically there are 340,282,366,920,938,463,463,374,607,431,768,211,456 addresses available. This means there are approximately 6.67 * 10^27 IPv6 addresses per square meter on our planet. Routers will only store network aggregation addresses in their routing tables thus reducing the average space of a routing table to 8192 entries. There are also lots of other useful features of IPv6 such as: Address autoconfiguration (RFC2462) Anycast addresses (one-out-of many) Mandatory multicast addresses IPsec (IP security) Simplified header structure Mobile IP IPv4-to-IPv6 transition mechanisms For more information see: IPv6 overview at Sun.com IPv6.org KAME.net 6bone.net Background on IPv6 Addresses There are different types of IPv6 addresses: Unicast, Anycast and Multicast. Unicast addresses are the well known addresses. A packet sent to a unicast address arrives exactly at the interface belonging to the address. Anycast addresses are syntactically indistinguishable from unicast addresses but they address a group of interfaces. The packet destined for an anycast address will arrive at the nearest (in router metric) interface. Anycast addresses may only be used by routers. Multicast addresses identify a group of interfaces. A packet destined for a multicast address will arrive at all interfaces belonging to the multicast group. The IPv4 broadcast address (usually xxx.xxx.xxx.255) is expressed by multicast addresses in IPv6. Reserved IPv6 addresses: ipv6-address prefixlength(Bits) description Notes :: 128 Bits unspecified cf. 0.0.0.0 in IPv4 address ::1 128 Bits loopback address cf. 127.0.0.1 in IPv4 ::00:xx:xx:xx:xx 96 Bits embedded IPv4 The lower 32 bits are the address IPv4 address. Also called IPv4 compatible IPv6 address ::ff:xx:xx:xx:xx 96 Bits IPv4 mapped The lower 32 bits are the IPv6 address IPv4 address. For hosts which do not support IPv6 fe80:: - feb:: 10 Bits link-local cf. loopback address in IPv4 fec0:: - fef:: 10 Bits site-local ff:: 8 Bits multicast 001 (base 2) 3 Bits global unicast All global unicast addresses are assigned from this pool. The first 3 Bits are 001. Reading IPv6 Addresses The canonical form is represented as: x:x:x:x:x:x:x:x, each x being a 16 Bit hex value. For example FEBC:A574:382B:23C1:AA49:4592:4EFE:9982 Often an address will have long substrings of all zeros therefore each such substring can be abbreviated by ::. For example fe80::1 corresponds to the canonical form fe80:0000:0000:0000:0000:0000:0000:0001 A third form is to write the last 32 Bit part in the well known (decimal) IPv4 style with dots . as separators. For example 2002::10.0.0.1 corresponds to the (hexadecimal) canonical representation 2002:0000:0000:0000:0000:0000:0a00:0001 which in turn is equivalent to writing 2002::a00:1 By now the reader should be able to understand the following: &prompt.root; ifconfig rl0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500 inet 10.0.0.10 netmask 0xffffff00 broadcast 10.0.0.255 inet6 fe80::200:21ff:fe03:8e1%rl0 prefixlen 64 scopeid 0x1 ether 00:00:21:03:08:e1 media: Ethernet autoselect (100baseTX ) status: active fe80::200:21ff:fe03:8e1%rl0 is an auto configured link-local address. It includes the - enscrambled Ethernet MAC as part of the auto configuration. + scrambled Ethernet MAC as part of the auto configuration. For further information on the structure of IPv6 addresses see RFC2373. Getting Connected Currently there are four ways to connect to other IPv6 hosts and networks: Join the experimental 6bone Getting an IPv6 network from your upstream provider. Talk to your Internet provider for instructions. Tunnel via 6-to-4 Use the freenet6 port if you are on a dial-up connection. Here we will talk on how to connect to the 6bone since it currently seems to be the most popular way. First take a look at the 6bone site and find a 6bone connection nearest to you. Write to the responsible person and with a little bit of luck you will be given instructions on how to set up your connection. Usually this involves setting up a GRE (gif) tunnel. Here is a typical example on setting up a &man.gif.4; tunnel: &prompt.root; ifconfig gif0 create &prompt.root; ifconfig gif0 gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280 &prompt.root; ifconfig gif0 tunnel MY_IPv4_ADDR HIS_IPv4_ADDR &prompt.root; ifconfig gif0 inet6 alias MY_ASSIGNED_IPv6_TUNNEL_ENDPOINT_ADDR Replace the capitalized words by the information you received from the upstream 6bone node. This establishes the tunnel. Check if the tunnel is working by &man.ping6.8; 'ing ff02::1%gif0. You should receive two ping replies. In case you are intrigued by the address ff02:1%gif0, this is a multicast address. %gif0 states that the multicast address at network interface gif0 is to be used. Since we ping a multicast address the other endpoint of the tunnel should reply as well). By now setting up a route to your 6bone uplink should be rather straightforward: &prompt.root; route add -inet6 default -interface gif0 &prompt.root; ping6 -n MY_UPLINK &prompt.root; traceroute6 www.jp.FreeBSD.org (3ffe:505:2008:1:2a0:24ff:fe57:e561) from 3ffe:8060:100::40:2, 30 hops max, 12 byte packets 1 atnet-meta6 14.147 ms 15.499 ms 24.319 ms 2 6bone-gw2-ATNET-NT.ipv6.tilab.com 103.408 ms 95.072 ms * 3 3ffe:1831:0:ffff::4 138.645 ms 134.437 ms 144.257 ms 4 3ffe:1810:0:6:290:27ff:fe79:7677 282.975 ms 278.666 ms 292.811 ms 5 3ffe:1800:0:ff00::4 400.131 ms 396.324 ms 394.769 ms 6 3ffe:1800:0:3:290:27ff:fe14:cdee 394.712 ms 397.19 ms 394.102 ms This output will differ from machine to machine. By now you should be able to reach the IPv6 site www.kame.net and see the dancing tortoise - that is if you have a IPv6 enabled browser such as mozilla. DNS in the IPv6 World There are two new types of DNS records for IPv6: AAAA records, A6 records Using AAAA records is straightforward. Assign your hostname to the new IPv6 address you just got by adding: MYHOSTNAME AAAA MYIPv6ADDR To your primary zone DNS file. In case you do not serve your own DNS zones ask your DNS provider. Current versions of bind (version 8.3 and 9) support AAAA records.
diff --git a/en_US.ISO8859-1/books/handbook/cutting-edge/chapter.sgml b/en_US.ISO8859-1/books/handbook/cutting-edge/chapter.sgml index 74e03d9532..550d432e5a 100644 --- a/en_US.ISO8859-1/books/handbook/cutting-edge/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/cutting-edge/chapter.sgml @@ -1,1851 +1,1851 @@ Jim Mock Restructured, reorganized, and parts updated by Jordan Hubbard Original work by Poul-Henning Kamp John Polstra Nik Clayton The Cutting Edge Synopsis &os; is under constant development between releases. For people who want to be on the cutting edge, there are several easy mechanisms for keeping your system in sync with the latest developments. Be warned—the cutting edge is not for everyone! This chapter will help you decide if you want to track the development system, or stick with one of the released versions. After reading this chapter, you will know: The difference between the two development branches: &os.stable; and &os.current;. How to keep your system up to date with CVSup, CVS, or CTM. How to rebuild and reinstall the entire base system with make world. Before reading this chapter, you should: Properly setup your network connection (). Know how to install additional third-party software (). &os.current; vs. &os.stable; -CURRENT -STABLE There are two development branches to FreeBSD: &os.current; and &os.stable;. This section will explain a bit about each and describe how to keep your system up-to-date with each respective tree. &os.current; will be discussed first, then &os.stable;. Staying Current with &os; As you read this, keep in mind that &os.current; is the bleeding edge of &os; development. &os.current; users are expected to have a high degree of technical skill, and should be capable of solving difficult system problems on their own. If you are new to &os;, think twice before installing it. What Is &os.current;? snapshot &os.current; is the latest working sources for &os;. This includes work in progress, experimental changes, and transitional mechanisms that might or might not be present in the next official release of the software. While many &os; developers compile the &os.current; source code daily, there are periods of time when the sources are not buildable. These problems are resolved as expeditiously as possible, but whether or not &os.current; brings disaster or greatly desired functionality can be a matter of which exact moment you grabbed the source code in! Who Needs &os.current;? &os.current; is made available for 3 primary interest groups: Members of the &os; group who are actively working on some part of the source tree and for whom keeping current is an absolute requirement. Members of the &os; group who are active testers, willing to spend time solving problems in order to ensure that &os.current; remains as sane as possible. These are also people who wish to make topical suggestions on changes and the general direction of &os;, and submit patches to implement them. Those who merely wish to keep an eye on things, or to use the current sources for reference purposes (e.g. for reading, not running). These people also make the occasional comment or contribute code. What Is &os.current; <emphasis>Not</emphasis>? A fast-track to getting pre-release bits because you heard there is some cool new feature in there and you want to be the first on your block to have it. Being the first on the block to get the new feature means that you're the first on the block to get the new bugs. A quick way of getting bug fixes. Any given version of &os.current; is just as likely to introduce new bugs as to fix existing ones. In any way officially supported. We do our best to help people genuinely in one of the 3 legitimate &os.current; groups, but we simply do not have the time to provide tech support. This is not because we are mean and nasty people who do not like helping people out (we would not even be doing &os; if we were). We simply cannot answer hundreds messages a day and work on FreeBSD! Given the choice between improving &os; and answering lots of questions on experimental code, the developers opt for the former. Using &os.current; -CURRENT using Join the &a.current.name; and the &a.cvsall.name; lists. This is not just a good idea, it is essential. If you are not on the &a.current.name; list, you will not see the comments that people are making about the current state of the system and thus will probably end up stumbling over a lot of problems that others have already found and solved. Even more importantly, you will miss out on important bulletins which may be critical to your system's continued health. The &a.cvsall.name; list will allow you to see the commit log entry for each change as it is made along with any pertinent information on possible side-effects. To join these lists, or one of the others available go to &a.mailman.lists.link; and click on the list that you wish to subscribe to. Instructions on the rest of the procedure are available there. Grab the sources from a &os; mirror site. You can do this in one of three ways: cvsup cron -CURRENT Syncing with CVSup Use the cvsup program with this supfile. This is the most recommended method, since it allows you to grab the entire collection once and then only what has changed from then on. Many people run cvsup from cron and keep their sources up-to-date automatically. You have to customize the sample supfile above, and configure cvsup for your environment. If you want help doing this configuration, simply type: &prompt.root; pkg_add -f ftp://ftp.freebsd.org/pub/FreeBSD/ports/packages/All/cvsupit-3.1.tgz -CURRENT Downloading with ftp Use ftp. The source tree for &os.current; is exported on some of the FTP mirrors in the directory /pub/FreeBSD/FreeBSD-current/. Some of our FTP mirrors may also allow compressed/tarred grabbing of whole trees. For example you see: usr.bin/lex You can do the following to get the whole directory as a tar file: ftp> cd usr.bin ftp> get lex.tar If you wish to download the entire &os.current; source tree cvsup handles this much better than mirroring a FTP site. -CURRENT Syncing with CTM Use the CTM facility. If you have very bad connectivity (high price connections or only email access) CTM is an option. However, it is a lot of hassle and can give you broken files. This leads to it being rarely used, which again increases the chance of it not working for fairly long periods of time. We recommend using CVSup for anybody with a 9600 bps modem or faster connection. If you are grabbing the sources to run, and not just look at, then grab all of &os.current;, not just selected portions. The reason for this is that various parts of the source depend on updates elsewhere, and trying to compile just a subset is almost guaranteed to get you into trouble. -CURRENT compiling Before compiling &os.current;, read the Makefile in /usr/src carefully. You should at least run a make world the first time through as part of the upgrading process. Reading the &a.current; will keep you up-to-date on other bootstrapping procedures that sometimes become necessary as we move toward the next release. Be active! If you are running &os.current;, we want to know what you have to say about it, especially if you have suggestions for enhancements or bug fixes. Suggestions with accompanying code are received most enthusiastically! Staying Stable with &os; What Is &os.stable;? -STABLE &os.stable; is our development branch from which major releases are made. Changes go into this branch at a different pace, and with the general assumption that they have first gone into &os.current; for testing. This is still a development branch, however, and this means that at any given time, the sources for &os.stable; may or may not be suitable for any particular purpose. It is simply another engineering development track, not a resource for end-users. Who Needs &os.stable;? If you are interested in tracking or contributing to the FreeBSD development process, especially as it relates to the next point release of FreeBSD, then you should consider following &os.stable;. While it is true that security fixes also go into the &os.stable; branch, you do not need to track &os.stable; to do this. Every security advisory for FreeBSD explains how to fix the problem for the releases it affects That is not quite true. We can not continue to support old releases of FreeBSD forever, although we do support them for many years. For a complete description of the current security policy for old releases of FreeBSD, please see http://www.FreeBSD.org/security/ , and tracking an entire development branch just for security reasons is likely to bring in a lot of unwanted changes as well. Although we endeavor to ensure that the &os.stable; branch compiles and runs at all times, this cannot be guaranteed. In addition, while code is developed in &os.current; before including it in &os.stable;, more people run &os.stable; than &os.current;, so it is inevitable that bugs and corner cases will sometimes be found in &os.stable; that were not apparent in &os.current;. For these reasons, we do not recommend that you blindly track &os.stable;, and it is particularly important that you do not update any production servers to &os.stable; without first thoroughly testing the code in your development environment. If you do not have the resources to do this then we recommend that you run the most recent release of FreeBSD, and use the binary update mechanism to move from release to release. Using &os.stable; -STABLE using Join the &a.stable.name; list. This will keep you informed of build-dependencies that may appear in &os.stable; or any other issues requiring special attention. Developers will also make announcements in this mailing list when they are contemplating some controversial fix or update, giving the users a chance to respond if they have any issues to raise concerning the proposed change. The &a.cvsall.name; list will allow you to see the commit log entry for each change as it is made along with any pertinent information on possible side-effects. To join these lists, or one of the others available go to &a.mailman.lists.link; and click on the list that you wish to subscribe to. Instructions on the rest of the procedure are available there. If you are installing a new system and want it to be as stable as possible, you can simply grab the latest dated branch snapshot from and install it like any other release. If you are already running a previous release of &os; and wish to upgrade via sources then you can easily do so from &os; mirror site. This can be done in one of three ways: cvsup cron -STABLE syncing with CVSup Use the cvsup program with this supfile. This is the most recommended method, since it allows you to grab the entire collection once and then only what has changed from then on. Many people run cvsup from cron to keep their sources up-to-date automatically. You have to customize the sample supfile above, and configure cvsup for your environment. If you want help doing this configuration, simply type:
&prompt.root; pkg_add -f ftp://ftp.freebsd.org/pub/FreeBSD/ports/packages/All/cvsupit-3.1.tgz
-STABLE downloading with FTP Use ftp. The source tree for &os.stable; is exported on some of the FTP mirrors in the directory /pub/FreeBSD/FreeBSD-stable/. Some of our FTP mirrors may also allow compressed/tarred grabbing of whole trees. For example you see: usr.bin/lex You can do the following to get the whole directory for you as a tar file: ftp> cd usr.bin ftp> get lex.tar If you wish to download the entire &os.stable; source tree cvsup handles this much better than mirroring a FTP site. -STABLE syncing with CTM Use the CTM facility. If you do not have a fast and inexpensive connection to the Internet, this is the method you should consider using.
Essentially, if you need rapid on-demand access to the source and communications bandwidth is not a consideration, use cvsup or ftp. Otherwise, use CTM. -STABLE compiling Before compiling &os.stable;, read the Makefile in /usr/src carefully. You should at least run a make world the first time through as part of the upgrading process. Reading the &a.stable; will keep you up-to-date on other bootstrapping procedures that sometimes become necessary as we move toward the next release.
Synchronizing Your Source There are various ways of using an Internet (or email) connection to stay up-to-date with any given area of the &os; project sources, or all areas, depending on what interests you. The primary services we offer are Anonymous CVS, CVSup, and CTM. While it is possible to update only parts of your source tree, the only supported update procedure is to update the entire tree and recompile both userland (i.e., all the programs that run in user space, such as those in /bin and /sbin) and kernel sources. Updating only part of your source tree, only the kernel, or only userland will often result in problems. These problems may range from compile errors to kernel panics or data corruption. anonymous CVS Anonymous CVS and CVSup use the pull model of updating sources. In the case of CVSup the user (or a cron script) invokes the cvsup program, and it interacts with a cvsupd server somewhere to bring your files up-to-date. The updates you receive are up-to-the-minute and you get them when, and only when, you want them. You can easily restrict your updates to the specific files or directories that are of interest to you. Updates are generated on the fly by the server, according to what you have and what you want to have. Anonymous CVS is quite a bit more simplistic than CVSup in that it is just an extension to CVS which allows it to pull changes directly from a remote CVS repository. CVSup can do this far more efficiently, but Anonymous CVS is easier to use. CTM CTM, on the other hand, does not interactively compare the sources you have with those on the master archive or otherwise pull them across. Instead, a script which identifies changes in files since its previous run is executed several times a day on the master CTM machine, any detected changes being compressed, stamped with a sequence-number and encoded for transmission over email (in printable ASCII only). Once received, these CTM deltas can then be handed to the &man.ctm.rmail.1; utility which will automatically decode, verify and apply the changes to the user's copy of the sources. This process is far more efficient than CVSup, and places less strain on our server resources since it is a push rather than a pull model. There are other trade-offs, of course. If you inadvertently wipe out portions of your archive, CVSup will detect and rebuild the damaged portions for you. CTM will not do this, and if you wipe some portion of your source tree out (and do not have it backed up) then you will have to start from scratch (from the most recent CVS base delta) and rebuild it all with CTM or, with Anonymous CVS, simply delete the bad bits and resync. Using <command>make world</command> make world Once you have synchronized your local source tree against a particular version of &os; (&os.stable;, &os.current;, and so on) you can then use the source tree to rebuild the system. Take a Backup It cannot be stressed enough how important it is to take a backup of your system before you do this. While rebuilding the world is (as long as you follow these instructions) an easy task to do, there will inevitably be times when you make mistakes, or when mistakes made by others in the source tree render your system unbootable. Make sure you have taken a backup. And have a fixit floppy to hand. You will probably never have to use it, but it is better to be safe than sorry! Subscribe to the Right Mailing List mailing list The &os.stable; and &os.current; branches are, by their nature, in development. People that contribute to &os; are human, and mistakes occasionally happen. Sometimes these mistakes can be quite harmless, just causing your system to print a new diagnostic warning. Or the change may be catastrophic, and render your system unbootable or destroy your file systems (or worse). If problems like these occur, a heads up is posted to the appropriate mailing list, explaining the nature of the problem and which systems it affects. And an all clear announcement is posted when the problem has been solved. If you try to track &os.stable; or &os.current; and do not read the &a.stable; or the &a.current; respectively, then you are asking for trouble. Read <filename>/usr/src/UPDATING</filename> Before you do anything else, read /usr/src/UPDATING (or the equivalent file wherever you have a copy of the source code). This file should contain important information about problems you might encounter, or specify the order in which you might have to run certain commands. If UPDATING contradicts something you read here, UPDATING takes precedence. Reading UPDATING is not an acceptable substitute for subscribing to the correct mailing list, as described previously. The two requirements are complementary, not exclusive. Check <filename>/etc/make.conf</filename> make.conf Examine the files /etc/defaults/make.conf and /etc/make.conf. The first contains some default defines – most of which are commented out. To make use of them when you rebuild your system from source, add them to /etc/make.conf. Keep in mind that anything you add to /etc/make.conf is also used every time you run make, so it is a good idea to set them to something sensible for your system. A typical user will probably want to copy the CFLAGS and NOPROFILE lines found in /etc/defaults/make.conf to /etc/make.conf and uncomment them. Examine the other definitions (COPTFLAGS, NOPORTDOCS and so on) and decide if they are relevant to you. Update the files in <filename>/etc</filename> The /etc directory contains a large part of your system's configuration information, as well as scripts that are run at system startup. Some of these scripts change from version to version of FreeBSD. Some of the configuration files are also used in the day to day running of the system. In particular, /etc/group. There have been occasions when the installation part of make world has expected certain usernames or groups to exist. When performing an upgrade it is likely that these users or groups did not exist. This caused problems when upgrading. A recent example of this is when the smmsp user was added. Users had the installation process fail for them when &man.mtree.8; was trying to create /var/spool/clientmqueue. The solution is to examine /usr/src/etc/group and compare its list of groups with your own. If there are any groups in the new file that are not in your file then copy them over. Similarly, you should rename any groups in /etc/group which have the same GID but a different name to those in /usr/src/etc/group. Since 4.6-RELEASE you can run &man.mergemaster.8; in pre-buildworld mode by providing the option. This will compare only those files that are essential for the success of buildworld or installworld. If your old version of mergemaster does not support , use the new version in the source tree when running for the first time: &prompt.root; cd /usr/src/usr.sbin/mergemaster &prompt.root; ./mergemaster.sh -p If you are feeling particularly paranoid, you can check your system to see which files are owned by the group you are renaming or deleting: &prompt.root; find / -group GID -print will show all files owned by group GID (which can be either a group name or a numeric group ID). Drop to Single User Mode single-user mode You may want to compile the system in single user mode. Apart from the obvious benefit of making things go slightly faster, reinstalling the system will touch a lot of important system files, all the standard system binaries, libraries, include files and so on. Changing these on a running system (particularly if you have active users on the system at the time) is asking for trouble. multi-user mode Another method is to compile the system in multi-user mode, and then drop into single user mode for the installation. If you would like to do it this way, simply hold off on the following steps until the build has completed. You can postpone dropping to single user mode until you have to installkernel or installworld. As the superuser, you can execute: &prompt.root; shutdown now from a running system, which will drop it to single user mode. Alternatively, reboot the system, and at the boot prompt, enter the flag. The system will then boot single user. At the shell prompt you should then run: &prompt.root; fsck -p &prompt.root; mount -u / &prompt.root; mount -a -t ufs &prompt.root; swapon -a This checks the file systems, remounts / read/write, mounts all the other UFS file systems referenced in /etc/fstab and then turns swapping on. If your CMOS clock is set to local time and not to GMT (this is true if the output of the &man.date.1; command does not show the correct time and zone), you may also need to run the following command: &prompt.root; adjkerntz -i - This will make sure that your local timezone settings + This will make sure that your local time-zone settings get set up correctly — without this, you may later run into some problems. Remove <filename>/usr/obj</filename> As parts of the system are rebuilt they are placed in directories which (by default) go under /usr/obj. The directories shadow those under /usr/src. You can speed up the make world process, and possibly save yourself some dependency headaches by removing this directory as well. Some files below /usr/obj may have the immutable flag set (see &man.chflags.1; for more information) which must be removed first. &prompt.root; cd /usr/obj &prompt.root; chflags -R noschg * &prompt.root; rm -rf * Recompile the Source Saving the Output It is a good idea to save the output you get from running &man.make.1; to another file. If something goes wrong you will have a copy of the error message. While this might not help you in diagnosing what has gone wrong, it can help others if you post your problem to one of the &os; mailing lists. The easiest way to do this is to use the &man.script.1; command, with a parameter that specifies the name of the file to save all output to. You would do this immediately before rebuilding the world, and then type exit when the process has finished. &prompt.root; script /var/tmp/mw.out Script started, output file is /var/tmp/mw.out &prompt.root; make TARGET … compile, compile, compile … &prompt.root; exit Script done, … If you do this, do not save the output in /tmp. This directory may be cleared next time you reboot. A better place to store it is in /var/tmp (as in the previous example) or in root's home directory. Compile the Base System You must be in the /usr/src directory: &prompt.root; cd /usr/src (unless, of course, your source code is elsewhere, in which case change to that directory instead). make To rebuild the world you use the &man.make.1; command. This command reads instructions from the Makefile, which describes how the programs that comprise &os; should be rebuilt, the order in which they should be built, and so on. The general format of the command line you will type is as follows: &prompt.root; make -x -DVARIABLE target In this example, is an option that you would pass to &man.make.1;. See the &man.make.1; manual page for an example of the options you can pass. passes a variable to the Makefile. The behavior of the Makefile is controlled by these variables. These are the same variables as are set in /etc/make.conf, and this provides another way of setting them. &prompt.root; make -DNOPROFILE target is another way of specifying that profiled libraries should not be built, and corresponds with the NOPROFILE= true # Avoid compiling profiled libraries line in /etc/make.conf. target tells &man.make.1; what you want to do. Each Makefile defines a number of different targets, and your choice of target determines what happens. Some targets are listed in the Makefile, but are not meant for you to run. Instead, they are used by the build process to break out the steps necessary to rebuild the system into a number of sub-steps. Most of the time you will not need to pass any parameters to &man.make.1;, and so your command like will look like this: &prompt.root; make target Beginning with version 2.2.5 of &os; (actually, it was first created on the &os.current; branch, and then retrofitted to &os.stable; midway between 2.2.2 and 2.2.5) the world target has been split in two: buildworld and installworld. As the names imply, buildworld builds a complete new tree under /usr/obj, and installworld installs this tree on the current machine. This is very useful for 2 reasons. First, it allows you to do the build safe in the knowledge that no components of your running system will be affected. The build is self hosted. Because of this, you can safely run buildworld on a machine running in multi-user mode with no fear of ill-effects. It is still recommended that you run the installworld part in single user mode, though. Secondly, it allows you to use NFS mounts to upgrade multiple machines on your network. If you have three machines, A, B and C that you want to upgrade, run make buildworld and make installworld on A. B and C should then NFS mount /usr/src and /usr/obj from A, and you can then run make installworld to install the results of the build on B and C. Although the world target still exists, you are strongly encouraged not to use it. Run &prompt.root; make buildworld It is now possible to specify a option to make which will cause it to spawn several simultaneous processes. This is most useful on multi-CPU machines. However, since much of the compiling process is IO bound rather than CPU bound it is also useful on single CPU machines. On a typical single-CPU machine you would run: &prompt.root; make -j4 buildworld &man.make.1; will then have up to 4 processes running at any one time. Empirical evidence posted to the mailing lists shows this generally gives the best performance benefit. If you have a multi-CPU machine and you are using an SMP configured kernel try values between 6 and 10 and see how they speed things up. Be aware that this is still somewhat experimental, and commits to the source tree may occasionally break this feature. If the world fails to compile using this parameter try again without it before you report any problems. Timings make world timings Many factors influence the build time, but currently a 500 MHz Pentium III with 128 MB of RAM takes about 2 hours to build the &os.stable; tree, with no tricks or shortcuts used during the process. A &os.current; tree will take somewhat longer. Compile and Install a New Kernel kernel compiling To take full advantage of your new system you should recompile the kernel. This is practically a necessity, as certain memory structures may have changed, and programs like &man.ps.1; and &man.top.1; will fail to work until the kernel and source code versions are the same. The simplest, safest way to do this is to build and install a kernel based on GENERIC. While GENERIC may not have all the necessary devices for your system, it should contain everything necessary to boot your system back to single user mode. This is a good test that the new system works properly. After booting from GENERIC and verifying that your system works you can then build a new kernel based on your normal kernel configuration file. If you are upgrading to &os; 4.0 or above then the old kernel build procedure (as described in ) is deprecated. Instead, you should run these commands after you have built the world with buildworld. If you want to build a custom kernel, and already have a configuration file, just use KERNCONF=MYKERNEL like this: &prompt.root; cd /usr/src &prompt.root; make buildkernel KERNCONF=MYKERNEL &prompt.root; make installkernel KERNCONF=MYKERNEL In FreeBSD 4.2 and older you must replace KERNCONF= with KERNEL=. 4.2-STABLE that was fetched before Feb 2nd, 2001 does not recognize KERNCONF=. Note that if you have raised kern.securelevel above 1 and you have set either the noschg or similar flags to your kernel binary, you might find it necessary to drop into single user mode to use installkernel. Otherwise you should be able to run both these commands from multi user mode without problems. See &man.init.8; for details about kern.securelevel and &man.chflags.1; for details about the various file flags. If you are upgrading to a version of &os; below 4.0 you should use the old kernel build procedure. However, it is recommended that you use the new version of &man.config.8;, using a command line like this. &prompt.root; /usr/obj/usr/src/usr.sbin/config/config KERNELNAME Reboot into Single User Mode single-user mode You should reboot into single user mode to test the new kernel works. Do this by following the instructions in . Install the New System Binaries If you were building a version of &os; recent enough to have used make buildworld then you should now use installworld to install the new system binaries. Run &prompt.root; cd /usr/src &prompt.root; make installworld If you specified variables on the make buildworld command line, you must specify the same variables in the make installworld command line. This does not necessarily hold true for other options; for example, must never be used with installworld. For example, if you ran: &prompt.root; make -DNOPROFILE buildworld you must install the results with: &prompt.root; make -DNOPROFILE installworld otherwise it would try to install profiled libraries that had not been built during the make buildworld phase. Update Files Not Updated by <command>make world</command> Remaking the world will not update certain directories (in particular, /etc, /var and /usr) with new or changed configuration files. The simplest way to update these files is to use &man.mergemaster.8;, though it is possible to do it manually if you would prefer to do that. Regardless of which way you choose, be sure to make a backup of /etc in case anything goes wrong. Tom Rhodes Contributed by <command>mergemaster</command> mergemaster The &man.mergemaster.8; utility is a Bourne script that will aid you in determining the differences between your configuration files in /etc, and the configuration files in the source tree /usr/src/etc. This is the recommended solution for keeping the system configuration files up to date with those located in the source tree. mergemaster was integrated into the FreeBSD base system between 3.3-RELEASE and 3.4-RELEASE, which means it is present in all -STABLE and -CURRENT systems since 3.3. To begin simply type mergemaster at your prompt, and watch it start going. mergemaster will then build a temporary root environment, from / down, and populate it with various system configuration files. Those files are then compared to the ones currently installed in your system. At this point, files that differ will be shown in &man.diff.1; format, with the sign representing added or modified lines, and representing lines that will be either removed completely, or replaced with a new line. See the &man.diff.1; manual page for more information about the &man.diff.1; syntax and how file differences are shown. &man.mergemaster.8; will then show you each file that displays variances, and at this point you will have the option of either deleting the new file (referred to as the temporary file), installing the temporary file in its unmodified state, merging the temporary file with the currently installed file, or viewing the &man.diff.1; results again. Choosing to delete the temporary file will tell &man.mergemaster.8; that we wish to keep our current file unchanged, and to delete the new version. This option is not recommended, unless you see no reason to change the current file. You can get help at any time by typing ? at the &man.mergemaster.8; prompt. If the user chooses to skip a file, it will be presented again after all other files have been dealt with. Choosing to install the unmodified temporary file will replace the current file with the new one. For most unmodified files, this is the best option. Choosing to merge the file will present you with a text editor, and the contents of both files. You can now merge them by reviewing both files side by side on the screen, and choosing parts from both to create a finished product. When the files are compared side by side, the l key will select the left contents and the r key will select contents from your right. The final output will be a file consisting of both parts, which can then be installed. This option is customarily used for files where settings have been modified by the user. Choosing to view the &man.diff.1; results again will show you the file differences just like &man.mergemaster.8; did before prompting you for an option. After &man.mergemaster.8; is done with the system files you will be prompted for other options. &man.mergemaster.8; may ask if you want to rebuild the password file and/or run &man.MAKEDEV.8; if you run a FreeBSD version prior to 5.0, and will finish up with an option to remove left-over temporary files. Manual Update If you wish to do the update manually, however, you cannot just copy over the files from /usr/src/etc to /etc and have it work. Some of these files must be installed first. This is because the /usr/src/etc directory is not a copy of what your /etc directory should look like. In addition, there are files that should be in /etc that are not in /usr/src/etc. If you are using &man.mergemaster.8; (as recommended), you can skip forward to the next section. The simplest way to do this by hand is to install the files into a new directory, and then work through them looking for differences. Backup Your Existing <filename>/etc</filename> Although, in theory, nothing is going to touch this directory automatically, it is always better to be sure. So copy your existing /etc directory somewhere safe. Something like: &prompt.root; cp -Rp /etc /etc.old does a recursive copy, preserves times, ownerships on files and suchlike. You need to build a dummy set of directories to install the new /etc and other files into. /var/tmp/root is a reasonable choice, and there are a number of subdirectories required under this as well. &prompt.root; mkdir /var/tmp/root &prompt.root; cd /usr/src/etc &prompt.root; make DESTDIR=/var/tmp/root distrib-dirs distribution This will build the necessary directory structure and install the files. A lot of the subdirectories that have been created under /var/tmp/root are empty and should be deleted. The simplest way to do this is to: &prompt.root; cd /var/tmp/root &prompt.root; find -d . -type d | xargs rmdir 2>/dev/null This will remove all empty directories. (Standard error is redirected to /dev/null to prevent the warnings about the directories that are not empty.) /var/tmp/root now contains all the files that should be placed in appropriate locations below /. You now have to go through each of these files, determining how they differ with your existing files. Note that some of the files that will have been installed in /var/tmp/root have a leading .. At the time of writing the only files like this are shell startup files in /var/tmp/root/ and /var/tmp/root/root/, although there may be others (depending on when you are reading this). Make sure you use ls -a to catch them. The simplest way to do this is to use &man.diff.1; to compare the two files: &prompt.root; diff /etc/shells /var/tmp/root/etc/shells This will show you the differences between your /etc/shells file and the new /var/tmp/root/etc/shells file. Use these to decide whether to merge in changes that you have made or whether to copy over your old file. Name the New Root Directory (<filename>/var/tmp/root</filename>) with a Time Stamp, So You Can Easily Compare Differences Between Versions Frequently rebuilding the world means that you have to update /etc frequently as well, which can be a bit of a chore. You can speed this process up by keeping a copy of the last set of changed files that you merged into /etc. The following procedure gives one idea of how to do this. Make the world as normal. When you want to update /etc and the other directories, give the target directory a name based on the current date. If you were doing this on the 14th of February 1998 you could do the following: &prompt.root; mkdir /var/tmp/root-19980214 &prompt.root; cd /usr/src/etc &prompt.root; make DESTDIR=/var/tmp/root-19980214 \ distrib-dirs distribution Merge in the changes from this directory as outlined above. Do not remove the /var/tmp/root-19980214 directory when you have finished. When you have downloaded the latest version of the source and remade it, follow step 1. This will give you a new directory, which might be called /var/tmp/root-19980221 (if you wait a week between doing updates). You can now see the differences that have been made in the intervening week using &man.diff.1; to create a recursive diff between the two directories: &prompt.root; cd /var/tmp &prompt.root; diff -r root-19980214 root-19980221 Typically, this will be a much smaller set of differences than those between /var/tmp/root-19980221/etc and /etc. Because the set of differences is smaller, it is easier to migrate those changes across into your /etc directory. You can now remove the older of the two /var/tmp/root-* directories: &prompt.root; rm -rf /var/tmp/root-19980214 Repeat this process every time you need to merge in changes to /etc. You can use &man.date.1; to automate the generation of the directory names: &prompt.root; mkdir /var/tmp/root-`date "+%Y%m%d"` Update <filename>/dev</filename> DEVFS If you are running FreeBSD 5.0 or later you can safely skip this section. These versions use &man.devfs.5; to allocate device nodes transparently for the user. In most cases, the &man.mergemaster.8; tool will realize when it is necessary to update the device nodes, and offer to complete it automatically. These instructions tell how to update the device nodes manually. For safety's sake, this is a multi-step process. Copy /var/tmp/root/dev/MAKEDEV to /dev: &prompt.root; cp /var/tmp/root/dev/MAKEDEV /dev MAKEDEV If you used &man.mergemaster.8; to update /etc, then your MAKEDEV script should have been updated already, though it cannot hurt to check (with &man.diff.1;) and copy it manually if necessary. Now, take a snapshot of your current /dev. This snapshot needs to contain the permissions, ownerships, major and minor numbers of each filename, but it should not contain the time stamps. The easiest way to do this is to use &man.awk.1; to strip out some of the information: &prompt.root; cd /dev &prompt.root; ls -l | awk '{print $1, $2, $3, $4, $5, $6, $NF}' > /var/tmp/dev.out Remake all the device nodes: &prompt.root; sh MAKEDEV all Write another snapshot of the directory, this time to /var/tmp/dev2.out. Now look through these two files for any device node that you missed creating. There should not be any, but it is better to be safe than sorry. &prompt.root; diff /var/tmp/dev.out /var/tmp/dev2.out You are most likely to notice disk slice discrepancies which will involve commands such as: &prompt.root; sh MAKEDEV sd0s1 to recreate the slice entries. Your precise circumstances may vary. Update <filename>/stand</filename> This step is included only for completeness. It can safely be omitted. For the sake of completeness, you may want to update the files in /stand as well. These files consist of hard links to the /stand/sysinstall binary. This binary should be statically linked, so that it can work when no other file systems (and in particular /usr) have been mounted. &prompt.root; cd /usr/src/release/sysinstall &prompt.root; make all install Rebooting You are now done. After you have verified that everything appears to be in the right place you can reboot the system. A simple &man.fastboot.8; should do it: &prompt.root; fastboot Finished You should now have successfully upgraded your &os; system. Congratulations. If things went slightly wrong, it is easy to rebuild a particular piece of the system. For example, if you accidentally deleted /etc/magic as part of the upgrade or merge of /etc, the &man.file.1; command will stop working. In this case, the fix would be to run: &prompt.root; cd /usr/src/usr.bin/file &prompt.root; make all install Questions Do I need to re-make the world for every change? There is no easy answer to this one, as it depends on the nature of the change. For example, if you just ran CVSup, and it has shown the following files as being updated: src/games/cribbage/instr.c src/games/sail/pl_main.c src/release/sysinstall/config.c src/release/sysinstall/media.c src/share/mk/bsd.port.mk it probably is not worth rebuilding the entire world. You could just go to the appropriate sub-directories and make all install, and that's about it. But if something major changed, for example src/lib/libc/stdlib then you should either re-make the world, or at least those parts of it that are statically linked (as well as anything else you might have added that is statically linked). At the end of the day, it is your call. You might be happy re-making the world every fortnight say, and let changes accumulate over that fortnight. Or you might want to re-make just those things that have changed, and be confident you can spot all the dependencies. And, of course, this all depends on how often you want to upgrade, and whether you are tracking &os.stable; or &os.current;. My compile failed with lots of signal 11 (or other signal number) errors. What has happened? signal 11 This is normally indicative of hardware problems. (Re)making the world is an effective way to stress test your hardware, and will frequently throw up memory problems. These normally manifest themselves as the compiler mysteriously dying on receipt of strange signals. A sure indicator of this is if you can restart the make and it dies at a different point in the process. In this instance there is little you can do except start swapping around the components in your machine to determine which one is failing. Can I remove /usr/obj when I have finished? The short answer is yes. /usr/obj contains all the object files that were produced during the compilation phase. Normally, one of the first steps in the make world process is to remove this directory and start afresh. In this case, keeping /usr/obj around after you have finished makes little sense, and will free up a large chunk of disk space (currently about 340 MB). However, if you know what you are doing you can have make world skip this step. This will make subsequent builds run much faster, since most of sources will not need to be recompiled. The flip side of this is that subtle dependency problems can creep in, causing your build to fail in odd ways. This frequently generates noise on the &os; mailing lists, when one person complains that their build has failed, not realizing that it is because they have tried to cut corners. Can interrupted builds be resumed? This depends on how far through the process you got before you found a problem. In general (and this is not a hard and fast rule) the make world process builds new copies of essential tools (such as &man.gcc.1;, and &man.make.1;) and the system libraries. These tools and libraries are then installed. The new tools and libraries are then used to rebuild themselves, and are installed again. The entire system (now including regular user programs, such as &man.ls.1; or &man.grep.1;) is then rebuilt with the new system files. If you are at the last stage, and you know it (because you have looked through the output that you were storing) then you can (fairly safely) do: … fix the problem … &prompt.root; cd /usr/src &prompt.root; make -DNOCLEAN all This will not undo the work of the previous make world. If you see the message: -------------------------------------------------------------- Building everything.. -------------------------------------------------------------- in the make world output then it is probably fairly safe to do so. If you do not see that message, or you are not sure, then it is always better to be safe than sorry, and restart the build from scratch. How can I speed up making the world? Run in single user mode. Put the /usr/src and /usr/obj directories on separate file systems held on separate disks. If possible, put these disks on separate disk controllers. Better still, put these file systems across multiple disks using the &man.ccd.4; (concatenated disk driver) device. Turn off profiling (set NOPROFILE=true in /etc/make.conf). You almost certainly do not need it. Also in /etc/make.conf, set CFLAGS to something like . The optimization is much slower, and the optimization difference between and is normally negligible. lets the compiler use pipes rather than temporary files for communication, which saves disk access (at the expense of memory). Pass the option to &man.make.1; to run multiple processes in parallel. This usually helps regardless of whether you have a single or a multi processor machine. The file system holding /usr/src can be mounted (or remounted) with the option. This prevents the file system from recording the file access time. You probably do not need this information anyway. &prompt.root; mount -u -o noatime /usr/src The example assumes /usr/src is on its own file system. If it is not (if it is a part of /usr for example) then you will need to use that file system mount point, and not /usr/src. The file system holding /usr/obj can be mounted (or remounted) with the option. This causes disk writes to happen asynchronously. In other words, the write completes immediately, and the data is written to the disk a few seconds later. This allows writes to be clustered together, and can be a dramatic performance boost. Keep in mind that this option makes your file system more fragile. With this option there is an increased chance that, should power fail, the file system will be in an unrecoverable state when the machine restarts. If /usr/obj is the only thing on this file system then it is not a problem. If you have other, valuable data on the same file system then ensure your backups are fresh before you enable this option. &prompt.root; mount -u -o async /usr/obj As above, if /usr/obj is not on its own file system, replace it in the example with the name of the appropriate mount point. What do I do if something goes wrong? Make absolutely sure your environment has no extraneous cruft from earlier builds. This is simple enough. &prompt.root; chflags -R noschg /usr/obj/usr &prompt.root; rm -rf /usr/obj/usr &prompt.root; cd /usr/src &prompt.root; make cleandir &prompt.root; make cleandir Yes, make cleandir really should be run twice. Then restart the whole process, starting with make buildworld. If you still have problems, send the error and the output of uname -a to &a.questions;. Be prepared to answer other questions about your setup! Mike Meyer Contributed by Tracking for multiple machines NFS installing multiple machines If you have multiple machines that you want to track the same source tree, then having all of them download sources and rebuild everything seems like a waste of resources: disk space, network bandwidth, and CPU cycles. It is, and the solution is to have one machine do most of the work, while the rest of the machines mount that work via NFS. This section outlines a method of doing so. Preliminaries First, identify a set of machines that is going to run the same set of binaries, which we will call a build set. Each machine can have a custom kernel, but they will be running the same userland binaries. From that set, choose a machine to be the build machine. It is going to be the machine that the world and kernel are built on. Ideally, it should be a fast machine that has sufficient spare CPU to run make world. You will also want to choose a machine to be the test machine, which will test software updates before they are put into production. This must be a machine that you can afford to have down for an extended period of time. It can be the build machine, but need not be. All the machines in this build set need to mount /usr/obj and /usr/src from the same machine, and at the same point. Ideally, those are on two different drives on the build machine, but they can be NFS mounted on that machine as well. If you have multiple build sets, /usr/src should be on one build machine, and NFS mounted on the rest. Finally make sure that /etc/make.conf on all the machines in the build set agrees with the build machine. That means that the build machine must build all the parts of the base system that any machine in the build set is going to install. Also, each build machine should have its kernel name set with KERNCONF in /etc/make.conf, and the build machine should list them all in KERNCONF, listing its own kernel first. The build machine must have the kernel configuration files for each machine in /usr/src/sys/arch/conf if it is going to build their kernels. The base system Now that all that is done, you are ready to build everything. Build the kernel and world as described in on the build machine, but do not install anything. After the build has finished, go to the test machine, and install the kernel you just built. If this machine mounts /usr/src and /usr/obj via NFS, when you reboot to single user you will need to enable the network and mount them. The easiest way to do this is to boot to multi-user, then run shutdown now to go to single user mode. Once there, you can install the new kernel and world and run mergemaster just as you normally would. When done, reboot to return to normal multi-user operations for this machine. After you are certain that everything on the test machine is working properly, use the same procedure to install the new software on each of the other machines in the build set. Ports The same ideas can be used for the ports tree. The first critical step is mounting /usr/ports from the same machine to all the machines in the build set. You can then set up /etc/make.conf properly to share distfiles. You should set DISTDIR to a common shared directory that is writable by whichever user root is mapped to by your NFS mounts. Each machine should set WRKDIRPREFIX to a local build directory. Finally, if you are going to be building and distributing packages, you should set PACKAGES to a directory similar to DISTDIR.
diff --git a/en_US.ISO8859-1/books/handbook/disks/chapter.sgml b/en_US.ISO8859-1/books/handbook/disks/chapter.sgml index 4598894c37..0dc8837e17 100644 --- a/en_US.ISO8859-1/books/handbook/disks/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/disks/chapter.sgml @@ -1,3195 +1,3195 @@ Storage Synopsis This chapter covers the use of disks in FreeBSD. This includes memory-backed disks, network-attached disks, and standard SCSI/IDE storage devices. After reading this chapter, you will know: The terminology FreeBSD uses to describe the organization of data on a physical disk (partitions and slices). How to mount and unmount file systems. How to add additional hard disks to your system. How to setup virtual file systems, such as memory disks. How to use quotas to limit disk space usage. How to encrypt disks to secure them against attackers. How to create and burn CDs and DVDs on FreeBSD. The various storage media options for backups. How to use backup programs available under FreeBSD. How to backup to floppy disks. What snapshots are and how to use them efficiently. Device Names The following is a list of physical storage devices supported in FreeBSD, and the device names associated with them. Physical Disk Naming Conventions Drive type Drive device name IDE hard drives ad IDE CDROM drives acd SCSI hard drives and USB Mass storage devices da SCSI CDROM drives cd Assorted non-standard CDROM drives mcd for Mitsumi CD-ROM, scd for Sony CD-ROM, matcd for Matsushita/Panasonic CD-ROM The &man.matcd.4; driver has been removed in FreeBSD 4.X branch since October 5th, 2002 and does not exist in FreeBSD 5.0 and later. Floppy drives fd SCSI tape drives sa IDE tape drives ast Flash drives fla for DiskOnChip Flash device RAID drives aacd for Adaptec AdvancedRAID, mlxd and mlyd for Mylex, amrd for AMI MegaRAID, idad for Compaq Smart RAID, twed for 3Ware RAID.
David O'Brien Originally contributed by Adding Disks disks adding Lets say we want to add a new SCSI disk to a machine that currently only has a single drive. First turn off the computer and install the drive in the computer following the instructions of the computer, controller, and drive manufacturer. Due to the wide variations of procedures to do this, the details are beyond the scope of this document. Login as user root. After you have installed the drive, inspect /var/run/dmesg.boot to ensure the new disk was found. Continuing with our example, the newly added drive will be da1 and we want to mount it on /1 (if you are adding an IDE drive, the device name will be wd1 in pre-4.0 systems, or ad1 in most 4.X systems). partitions slices fdisk Because FreeBSD runs on IBM-PC compatible computers, it must take into account the PC BIOS partitions. These are different from the traditional BSD partitions. A PC disk has up to four BIOS partition entries. If the disk is going to be truly dedicated to FreeBSD, you can use the dedicated mode. Otherwise, FreeBSD will have to live within one of the PC BIOS partitions. FreeBSD calls the PC BIOS partitions slices so as not to confuse them with traditional BSD partitions. You may also use slices on a disk that is dedicated to FreeBSD, but used in a computer that also has another operating system installed. This is to not confuse the fdisk utility of the other operating system. In the slice case the drive will be added as /dev/da1s1e. This is read as: SCSI disk, unit number 1 (second SCSI disk), slice 1 (PC BIOS partition 1), and e BSD partition. In the dedicated case, the drive will be added simply as /dev/da1e. Using &man.sysinstall.8; sysinstall adding disks su Navigating <application>Sysinstall</application> You may use /stand/sysinstall to partition and label a new disk using its easy to use menus. Either login as user root or use the su command. Run /stand/sysinstall and enter the Configure menu. Within the FreeBSD Configuration Menu, scroll down and select the Fdisk option. <application>fdisk</application> Partition Editor Once inside fdisk, we can type A to use the entire disk for FreeBSD. When asked if you want to remain cooperative with any future possible operating systems, answer YES. Write the changes to the disk using W. Now exit the FDISK editor by typing q. Next you will be asked about the Master Boot Record. Since you are adding a disk to an already running system, choose None. Disk Label Editor BSD partitions Next, you need to exit sysinstall and start it again. Follow the directions above, although this time choose the Label option. This will enter the Disk Label Editor. This is where you will create the traditional BSD partitions. A disk can have up to eight partitions, labeled a-h. A few of the partition labels have special uses. The a partition is used for the root partition (/). Thus only your system disk (e.g, the disk you boot from) should have an a partition. The b partition is used for swap partitions, and you may have many disks with swap partitions. The c partition addresses the entire disk in dedicated mode, or the entire FreeBSD slice in slice mode. The other partitions are for general use. sysinstall's Label editor favors the e partition for non-root, non-swap partitions. Within the Label editor, create a single file system by typing C. When prompted if this will be a FS (file system) or swap, choose FS and type in a mount point (e.g, /mnt). When adding a disk in post-install mode, sysinstall will not create entries in /etc/fstab for you, so the mount point you specify is not important. You are now ready to write the new label to the disk and create a file system on it. Do this by typing W. Ignore any errors from sysinstall that it could not mount the new partition. Exit the Label Editor and sysinstall completely. Finish The last step is to edit /etc/fstab to add an entry for your new disk. Using Command Line Utilities Using Slices This setup will allow your disk to work correctly with other operating systems that might be installed on your computer and will not confuse other operating systems' fdisk utilities. It is recommended to use this method for new disk installs. Only use dedicated mode if you have a good reason to do so! &prompt.root; dd if=/dev/zero of=/dev/da1 bs=1k count=1 &prompt.root; fdisk -BI da1 #Initialize your new disk &prompt.root; disklabel -B -w -r da1s1 auto #Label it. &prompt.root; disklabel -e da1s1 # Edit the disklabel just created and add any partitions. &prompt.root; mkdir -p /1 &prompt.root; newfs /dev/da1s1e # Repeat this for every partition you created. &prompt.root; mount /dev/da1s1e /1 # Mount the partition(s) &prompt.root; vi /etc/fstab # Add the appropriate entry/entries to your /etc/fstab. If you have an IDE disk, substitute ad for da. On pre-4.X systems use wd. Dedicated OS/2 If you will not be sharing the new drive with another operating system, you may use the dedicated mode. Remember this mode can confuse Microsoft operating systems; however, no damage will be done by them. IBM's OS/2 however, will appropriate any partition it finds which it does not understand. &prompt.root; dd if=/dev/zero of=/dev/da1 bs=1k count=1 &prompt.root; disklabel -Brw da1 auto &prompt.root; disklabel -e da1 # create the `e' partition &prompt.root; newfs -d0 /dev/da1e &prompt.root; mkdir -p /1 &prompt.root; vi /etc/fstab # add an entry for /dev/da1e &prompt.root; mount /1 An alternate method is: &prompt.root; dd if=/dev/zero of=/dev/da1 count=2 &prompt.root; disklabel /dev/da1 | disklabel -BrR da1 /dev/stdin &prompt.root; newfs /dev/da1e &prompt.root; mkdir -p /1 &prompt.root; vi /etc/fstab # add an entry for /dev/da1e &prompt.root; mount /1 RAID Software RAID Christopher Shumway Original work by Jim Brown Revised by RAIDSoftware RAIDCCD Concatenated Disk Driver (CCD) Configuration When choosing a mass storage solution the most important factors to consider are speed, reliability, and cost. It is rare to have all three in balance; normally a fast, reliable mass storage device is expensive, and to cut back on cost either speed or reliability must be sacrificed. In designing the system described below, cost was chosen as the most important factor, followed by speed, then reliability. Data transfer speed for this system is ultimately constrained by the network. And while reliability is very important, the CCD drive described below serves online data that is already fully backed up on CD-R's and can easily be replaced. Defining your own requirements is the first step in choosing a mass storage solution. If your requirements prefer speed or reliability over cost, your solution will differ from the system described in this section. Installing the Hardware In addition to the IDE system disk, three Western Digital 30GB, 5400 RPM IDE disks form the core of the CCD disk described below providing approximately 90GB of online storage. Ideally, each IDE disk would have its own IDE controller and cable, but to minimize cost, additional IDE controllers were not used. Instead the disks were configured with jumpers so that each IDE controller has one master, and one slave. Upon reboot, the system BIOS was configured to automatically detect the disks attached. More importantly, FreeBSD detected them on reboot: ad0: 19574MB <WDC WD205BA> [39770/16/63] at ata0-master UDMA33 ad1: 29333MB <WDC WD307AA> [59598/16/63] at ata0-slave UDMA33 ad2: 29333MB <WDC WD307AA> [59598/16/63] at ata1-master UDMA33 ad3: 29333MB <WDC WD307AA> [59598/16/63] at ata1-slave UDMA33 If FreeBSD does not detect all the disks, ensure that you have jumpered them correctly. Most IDE drives also have a Cable Select jumper. This is not the jumper for the master/slave relationship. Consult the drive documentation for help in identifying the correct jumper. Next, consider how to attach them as part of the file system. You should research both &man.vinum.8; () and &man.ccd.4;. In this particular configuration, &man.ccd.4; was chosen. Setting up the CCD The driver &man.ccd.4; allows you to take several identical disks and concatenate them into one logical file system. In order to use &man.ccd.4;, you need a kernel with &man.ccd.4; support built in. Add this line to your kernel configuration file, rebuild, and reinstall the kernel: pseudo-device ccd 4 On 5.X systems, you have to use instead the following line: device ccd In FreeBSD 5.X, it is not necessary to specify a number of &man.ccd.4; devices, as the &man.ccd.4; device driver is now self-cloning — new device instances will automatically be created on demand. The &man.ccd.4; support can also be loaded as a kernel loadable module in FreeBSD 3.0 or later. To set up &man.ccd.4;, you must first use &man.disklabel.8; to label the disks: disklabel -r -w ad1 auto disklabel -r -w ad2 auto disklabel -r -w ad3 auto This creates a disklabel for ad1c, ad2c and ad3c that spans the entire disk. The next step is to change the disk label type. You can use &man.disklabel.8; to edit the disks: disklabel -e ad1 disklabel -e ad2 disklabel -e ad3 This opens up the current disk label on each disk with the editor specified by the EDITOR environment variable, typically &man.vi.1;. An unmodified disk label will look something like this: 8 partitions: # size offset fstype [fsize bsize bps/cpg] c: 60074784 0 unused 0 0 0 # (Cyl. 0 - 59597) Add a new e partition for &man.ccd.4; to use. This can usually be copied from the c partition, but the must be 4.2BSD. The disk label should now look something like this: 8 partitions: # size offset fstype [fsize bsize bps/cpg] c: 60074784 0 unused 0 0 0 # (Cyl. 0 - 59597) e: 60074784 0 4.2BSD 0 0 0 # (Cyl. 0 - 59597) Building the File System The device node for ccd0c may not exist yet, so to create it, perform the following commands: cd /dev sh MAKEDEV ccd0 In FreeBSD 5.0, &man.devfs.5; will automatically manage device nodes in /dev, so use of MAKEDEV is not necessary. Now that you have all of the disks labeled, you must build the &man.ccd.4;. To do that, use &man.ccdconfig.8;, with options similar to the following: ccdconfig ccd0 32 0 /dev/ad1e /dev/ad2e /dev/ad3e The use and meaning of each option is shown below: The first argument is the device to configure, in this case, /dev/ccd0c. The /dev/ portion is optional. The interleave for the file system. The interleave defines the size of a stripe in disk blocks, each normally 512 bytes. So, an interleave of 32 would be 16,384 bytes. Flags for &man.ccdconfig.8;. If you want to enable drive mirroring, you can specify a flag here. This configuration does not provide mirroring for &man.ccd.4;, so it is set at 0 (zero). The final arguments to &man.ccdconfig.8; are the devices to place into the array. Use the complete pathname for each device. After running &man.ccdconfig.8; the &man.ccd.4; is configured. A file system can be installed. Refer to &man.newfs.8; for options, or simply run: newfs /dev/ccd0c Making it all Automatic Generally, you will want to mount the &man.ccd.4; upon each reboot. To do this, you must configure it first. Write out your current configuration to /etc/ccd.conf using the following command: ccdconfig -g > /etc/ccd.conf During reboot, the script /etc/rc runs ccdconfig -C if /etc/ccd.conf exists. This automatically configures the &man.ccd.4; so it can be mounted. If you are booting into single user mode, before you can &man.mount.8; the &man.ccd.4;, you need to issue the following command to configure the array: ccdconfig -C To automatically mount the &man.ccd.4;, place an entry for the &man.ccd.4; in /etc/fstab so it will be mounted at boot time: /dev/ccd0c /media ufs rw 2 2 The Vinum Volume Manager RAIDSoftware RAID Vinum The Vinum Volume Manager is a block device driver which implements virtual disk drives. It isolates disk hardware from the block device interface and maps data in ways which result in an increase in flexibility, performance and reliability compared to the traditional slice view of disk storage. &man.vinum.8; implements the RAID-0, RAID-1 and RAID-5 models, both individually and in combination. See for more information about &man.vinum.8;. Hardware RAID RAID Hardware FreeBSD also supports a variety of hardware RAID controllers. These devices control a RAID subsystem without the need for FreeBSD specific software to manage the array. Using an on-card BIOS, the card controls most of the disk operations itself. The following is a brief setup description using a Promise IDE RAID controller. When this card is installed and the system is started up, it displays a prompt requesting information. Follow the instructions to enter the card's setup screen. From here, you have the ability to combine all the attached drives. After doing so, the disk(s) will look like a single drive to FreeBSD. Other RAID levels can be set up accordingly. Rebuilding ATA RAID1 Arrays FreeBSD allows you to hot-replace a failed disk in an array. This requires that you catch it before you reboot. You will probably see something like the following in /var/log/messages or in the &man.dmesg.8; output: ad6 on monster1 suffered a hard error. ad6: READ command timeout tag=0 serv=0 - resetting ad6: trying fallback to PIO mode ata3: resetting devices .. done ad6: hard error reading fsbn 1116119 of 0-7 (ad6 bn 1116119; cn 1107 tn 4 sn 11) status=59 error=40 ar0: WARNING - mirror lost Using &man.atacontrol.8;, check for further information: &prompt.root; atacontrol list ATA channel 0: Master: no device present Slave: acd0 <HL-DT-ST CD-ROM GCR-8520B/1.00> ATA/ATAPI rev 0 ATA channel 1: Master: no device present Slave: no device present ATA channel 2: Master: ad4 <MAXTOR 6L080J4/A93.0500> ATA/ATAPI rev 5 Slave: no device present ATA channel 3: Master: ad6 <MAXTOR 6L080J4/A93.0500> ATA/ATAPI rev 5 Slave: no device present &prompt.root; atacontrol status ar0 ar0: ATA RAID1 subdisks: ad4 ad6 status: DEGRADED You will first need to detach the disk from the array so that you can safely remove it: &prompt.root; atacontrol detach 3 Replace the disk. Reattach the disk as a spare: &prompt.root; atacontrol attach 3 Master: ad6 <MAXTOR 6L080J4/A93.0500> ATA/ATAPI rev 5 Slave: no device present Rebuild the array: &prompt.root; atacontrol rebuild ar0 The rebuild command hangs until complete. However, it is possible to open another terminal (using Alt Fn) and check on the progress by issuing the following command: &prompt.root; dmesg | tail -10 [output removed] ad6: removed from configuration ad6: deleted from ar0 disk1 ad6: inserted into ar0 disk1 as spare &prompt.root; atacontrol status ar0 ar0: ATA RAID1 subdisks: ad4 ad6 status: REBUILDING 0% completed Wait until this operation completes. Mike Meyer Contributed by Creating and Using Optical Media (CDs & DVDs) CDROMs creating Introduction CDs have a number of features that differentiate them from conventional disks. Initially, they were not writable by the user. They are designed so that they can be read continuously without delays to move the head between tracks. They are also much easier to transport between systems than similarly sized media were at the time. CDs do have tracks, but this refers to a section of data to be read continuously and not a physical property of the disk. To produce a CD on FreeBSD, you prepare the data files that are going to make up the tracks on the CD, then write the tracks to the CD. ISO 9660 file systems ISO 9660 The ISO 9660 file system was designed to deal with these differences. It unfortunately codifies file system limits that were common then. Fortunately, it provides an extension mechanism that allows properly written CDs to exceed those limits while still working with systems that do not support those extensions. sysutils/mkisofs The sysutils/mkisofs program is used to produce a data file containing an ISO 9660 file system. It has options that support various extensions, and is described below. You can install it with the sysutils/mkisofs port. CD burner ATAPI Which tool to use to burn the CD depends on whether your CD burner is ATAPI or something else. ATAPI CD burners use the burncd program that is part of the base system. SCSI and USB CD burners should use cdrecord from the sysutils/cdrtools port. burncd has a limited number of supported drives. To find out if a drive is supported, see the CD-R/RW supported drives list. CD burner ATAPI/CAM driver If you run &os; 5.X, &os; 4.8-RELEASE version or higher, it will be possible to use cdrecord and other tools for SCSI drives on an ATAPI hardware with the ATAPI/CAM module. mkisofs sysutils/mkisofs produces an ISO 9660 file system that is an image of a directory tree in the Unix file system name space. The simplest usage is: &prompt.root; mkisofs -o imagefile.iso /path/to/tree file systems ISO 9660 This command will create an imagefile.iso containing an ISO 9660 file system that is a copy of the tree at /path/to/tree. In the process, it will map the file names to names that fit the limitations of the standard ISO 9660 file system, and will exclude files that have names uncharacteristic of ISO file systems. file systems HFS file systems Joliet A number of options are available to overcome those restrictions. In particular, enables the Rock Ridge extensions common to Unix systems, enables Joliet extensions used by Microsoft systems, and can be used to create HFS file systems used by MacOS. For CDs that are going to be used only on FreeBSD systems, can be used to disable all filename restrictions. When used with , it produces a file system image that is identical to the FreeBSD tree you started from, though it may violate the ISO 9660 standard in a number of ways. CDROMs creating bootable The last option of general use is . This is used to specify the location of the boot image for use in producing an El Torito bootable CD. This option takes an argument which is the path to a boot image from the top of the tree being written to the CD. So, given that /tmp/myboot holds a bootable FreeBSD system with the boot image in /tmp/myboot/boot/cdboot, you could produce the image of an ISO 9660 file system in /tmp/bootable.iso like so: &prompt.root; mkisofs -U -R -b boot/cdboot -o /tmp/bootable.iso /tmp/myboot Having done that, if you have vn (FreeBSD 4.X), or md (FreeBSD 5.X) configured in your kernel, you can mount the file system with: &prompt.root; vnconfig -e vn0c /tmp/bootable.iso &prompt.root; mount -t cd9660 /dev/vn0c /mnt for FreeBSD 4.X, and for FreeBSD 5.X: &prompt.root; mdconfig -a -t vnode -f /tmp/bootable.iso -u 0 &prompt.root; mount -t cd9660 /dev/md0 /mnt At which point you can verify that /mnt and /tmp/myboot are identical. There are many other options you can use with sysutils/mkisofs to fine-tune its behavior. In particular: modifications to an ISO 9660 layout and the creation of Joliet and HFS discs. See the &man.mkisofs.8; manual page for details. burncd CDROMs burning If you have an ATAPI CD burner, you can use the burncd command to burn an ISO image onto a CD. burncd is part of the base system, installed as /usr/sbin/burncd. Usage is very simple, as it has few options: &prompt.root; burncd -f cddevice data imagefile.iso fixate Will burn a copy of imagefile.iso on cddevice. The default device is /dev/acd0c. See &man.burncd.8; for options to set the write speed, eject the CD after burning, and write audio data. cdrecord If you do not have an ATAPI CD burner, you will have to use cdrecord to burn your CDs. cdrecord is not part of the base system; you must install it from either the port at sysutils/cdrtools or the appropriate package. Changes to the base system can cause binary versions of this program to fail, possibly resulting in a coaster. You should therefore either upgrade the port when you upgrade your system, or if you are tracking -STABLE, upgrade the port when a new version becomes available. While cdrecord has many options, basic usage is even simpler than burncd. Burning an ISO 9660 image is done with: &prompt.root; cdrecord dev=device imagefile.iso The tricky part of using cdrecord is finding the to use. To find the proper setting, use the flag of cdrecord, which might produce results like this: CDROMs burning &prompt.root; cdrecord -scanbus Cdrecord 1.9 (i386-unknown-freebsd4.2) Copyright (C) 1995-2000 Jörg Schilling Using libscg version 'schily-0.1' scsibus0: 0,0,0 0) 'SEAGATE ' 'ST39236LW ' '0004' Disk 0,1,0 1) 'SEAGATE ' 'ST39173W ' '5958' Disk 0,2,0 2) * 0,3,0 3) 'iomega ' 'jaz 1GB ' 'J.86' Removable Disk 0,4,0 4) 'NEC ' 'CD-ROM DRIVE:466' '1.26' Removable CD-ROM 0,5,0 5) * 0,6,0 6) * 0,7,0 7) * scsibus1: 1,0,0 100) * 1,1,0 101) * 1,2,0 102) * 1,3,0 103) * 1,4,0 104) * 1,5,0 105) 'YAMAHA ' 'CRW4260 ' '1.0q' Removable CD-ROM 1,6,0 106) 'ARTEC ' 'AM12S ' '1.06' Scanner 1,7,0 107) * This lists the appropriate value for the devices on the list. Locate your CD burner, and use the three numbers separated by commas as the value for . In this case, the CRW device is 1,5,0, so the appropriate input would be . There are easier ways to specify this value; see &man.cdrecord.1; for details. That is also the place to look for information on writing audio tracks, controlling the speed, and other things. Duplicating Audio CDs You can duplicate an audio CD by extracting the audio data from the CD to a series of files, and then writing these files to a blank CD. The process is slightly different for ATAPI and SCSI drives. SCSI drives Use cdda2wav to extract the audio. &prompt.user; cdda2wav -v255 -D2,0 -B -Owav Use cdrecord to write the .wav files. &prompt.user; cdrecord -v dev=2,0 -dao -useinfo *.wav Make sure that 2.0 is set appropriately, as described in . ATAPI drives The ATAPI CD driver makes each track available as /dev/acddtnn, where d is the drive number, and nn is the track number written with two decimal digits, prefixed with zero as needed. So the first track on the first disk is /dev/acd0t01, the second is /dev/acd0t02, the third is /dev/acd0t03, and so on. Make sure the appropriate files exist in /dev. &prompt.root; cd /dev &prompt.root; sh MAKEDEV acd0t99 In FreeBSD 5.0, &man.devfs.5; will automatically create and manage entries in /dev for you, so it is not necessary to use MAKEDEV. Extract each track using &man.dd.1;. You must also use a specific block size when extracting the files. &prompt.root; dd if=/dev/acd0t01 of=track1.cdr bs=2352 &prompt.root; dd if=/dev/acd0t02 of=track2.cdr bs=2352 ... Burn the extracted files to disk using burncd. You must specify that these are audio files, and that burncd should fixate the disk when finished. &prompt.root; burncd -f /dev/acd0c audio track1.cdr track2.cdr ... fixate Duplicating Data CDs You can copy a data CD to a image file that is functionally equivalent to the image file created with sysutils/mkisofs, and you can use it to duplicate any data CD. The example given here assumes that your CDROM device is acd0. Substitute your correct CDROM device. A c must be appended to the end of the device name to indicate the entire partition or, in the case of CDROMs, the entire disc. &prompt.root; dd if=/dev/acd0c of=file.iso bs=2048 Now that you have an image, you can burn it to CD as described above. Using Data CDs Now that you have created a standard data CDROM, you probably want to mount it and read the data on it. By default, &man.mount.8; assumes that a file system is of type ufs. If you try something like: &prompt.root; mount /dev/cd0c /mnt you will get a complaint about Incorrect super block, and no mount. The CDROM is not a UFS file system, so attempts to mount it as such will fail. You just need to tell &man.mount.8; that the file system is of type ISO9660, and everything will work. You do this by specifying the option &man.mount.8;. For example, if you want to mount the CDROM device, /dev/cd0c, under /mnt, you would execute: &prompt.root; mount -t cd9660 /dev/cd0c /mnt Note that your device name (/dev/cd0c in this example) could be different, depending on the interface your CDROM uses. Also, the option just executes &man.mount.cd9660.8;. The above example could be shortened to: &prompt.root; mount_cd9660 /dev/cd0c /mnt You can generally use data CDROMs from any vendor in this way. Disks with certain ISO 9660 extensions might behave oddly, however. For example, Joliet disks store all filenames in two-byte Unicode characters. The FreeBSD kernel does not speak Unicode (yet!), so non-English characters show up as question marks. (If you are running FreeBSD 4.3 or later, the CD9660 driver includes hooks to load an appropriate Unicode conversion table on the fly. Modules for some of the common encodings are available via the sysutils/cd9660_unicode port.) Occasionally, you might get Device not configured when trying to mount a CDROM. This usually means that the CDROM drive thinks that there is no disk in the tray, or that the drive is not visible on the bus. It can take a couple of seconds for a CDROM drive to realize that it has been fed, so be patient. Sometimes, a SCSI CDROM may be missed because it didn't have enough time to answer the bus reset. If you have a SCSI CDROM please add the following option to your kernel configuration and rebuild your kernel. options SCSI_DELAY=15000 This tells your SCSI bus to pause 15 seconds during boot, to give your CDROM drive every possible chance to answer the bus reset. Burning Raw Data CDs You can choose to burn a file directly to CD, without creating an ISO 9660 file system. Some people do this for backup purposes. This runs more quickly than burning a standard CD: &prompt.root; burncd -f /dev/acd1c -s 12 data archive.tar.gz fixate In order to retrieve the data burned to such a CD, you must read data from the raw device node: &prompt.root; tar xzvf /dev/acd1c You cannot mount this disk as you would a normal CDROM. Such a CDROM cannot be read under any operating system except FreeBSD. If you want to be able to mount the CD, or share data with another operating system, you must use sysutils/mkisofs as described above. CD burner ATAPI/CAM driver Using the ATAPI/CAM Driver This driver allows ATAPI devices (CD-ROM, CD-RW, DVD drives etc...) to be accessed through the SCSI subsystem, and so allows the use of applications like sysutils/cdrdao or &man.cdrecord.1;. To use this driver, you will need to add the following lines to your kernel configuration file: device atapicam device scbus device cd device pass You also need the following lines in your kernel configuration file: device ata device atapicd Both of which should already be present. Then rebuild, install your new kernel, and reboot your machine. During the boot process, your burner should show up, like so: acd0: CD-RW <MATSHITA CD-RW/DVD-ROM UJDA740> at ata1-master PIO4 cd0 at ata1 bus 0 target 0 lun 0 cd0: <MATSHITA CDRW/DVD UJDA740 1.00> Removable CD-ROM SCSI-0 device cd0: 16.000MB/s transfers cd0: Attempt to query device size failed: NOT READY, Medium not present - tray closed The drive could now be accessed via the /dev/cd0 device name, for example to mount a CD-ROM on /mnt, just type the following: &prompt.root; mount -t cd9660 /dev/cd0c /mnt As root, you can run the following command to get the SCSI address of the burner: &prompt.root; camcontrol devlist <MATSHITA CDRW/DVD UJDA740 1.00> at scbus1 target 0 lun 0 (pass0,cd0) So 1,0,0 will be the SCSI address to use with &man.cdrecord.1; and other SCSI application. For more information about ATAPI/CAM and SCSI system, refer to the &man.atapicam.4; and &man.cam.4; manual pages. Julio Merino Original work by Martin Karlsson Rewritten by Creating and Using Floppy Disks Storing data on floppy disks is sometimes useful, for example when one does not have any other removable storage media or when one needs to transfer small amounts of data to another computer. This section will explain how to use floppy disks in FreeBSD. It will primarily cover formatting and usage of 3.5inch DOS floppies, but the concepts are similar for other floppy disk formats. Formatting floppies The device Floppy disks are accessed through entries in /dev, just like other devices. To access the raw floppy disk in 4.X and earlier releases, one uses /dev/fdN, where N stands for the drive number, usually 0, or /dev/fdNX, where X stands for a letter. In 5.0 or newer releases, simply use /dev/fdN. The disk size in 4.X and earlier releases There are also /dev/fdN.size devices, where size is a floppy disk size in kilobytes. These entries are used at low-level format time to determine the disk size. 1440kB is the size that will be used in the following examples Sometimes the entries under /dev will have to be (re)created. To do that, issue: &prompt.root; cd /dev && ./MAKEDEV "fd*" The disk size in 5.0 and newer releases In 5.0, &man.devfs.5; will automatically manage device nodes in /dev, so use of MAKEDEV is not necessary. The desired disk size is passed to &man.fdformat.1; through the -f flag. Supported sizes are listed in &man.fdcontrol.8;, but be advised that 1440kB is what works best. Formatting A floppy disk needs to be low-level formated before it can be used. This is usually done by the vendor, but formatting is a good way to check media integrity. Although it is possible to force larger (or smaller) disk sizes, 1440kB is what most floppy disks are designed for. To low-level format the floppy disk you need to use &man.fdformat.1;. This utility expects the device name as an argument. Make note of any error messages, as these can help determine if the disk is good or bad. Formatting in 4.X and earlier releases Use the /dev/fdN.size devices to format the floppy. Insert a new 3.5inch floppy disk in your drive and issue: &prompt.root; /usr/sbin/fdformat /dev/fd0.1440 Formatting in 5.0 and newer releases Use the /dev/fdN devices to format the floppy. Insert a new 3.5inch floppy disk in your drive and issue: &prompt.root; /usr/sbin/fdformat -f 1440 /dev/fd0 The disklabel After low-level formatting the disk, you will need to place a disklabel on it. This disklabel will be destroyed later, but it is needed by the system to determine the size of the disk and its geometry later. The new disklabel will take over the whole disk, and will contain all the proper information about the geometry of the floppy. The geometry values for the disklabel are listed in /etc/disktab. You can run now &man.disklabel.8; like so: &prompt.root; /sbin/disklabel -B -r -w /dev/fd0 fd1440 The file system Now the floppy is ready to be high-level formated. This will place a new file system on it, which will let FreeBSD read and write to the disk. After creating the new file system, the disklabel is destroyed, so if you want to reformat the disk, you will have to recreate the disklabel. The floppy's file system can be either UFS or FAT. FAT is generally a better choice for floppies. To put a new file system on the floppy, issue: &prompt.root; /sbin/newfs_msdos /dev/fd0 The disk is now ready for use. Using the floppy To use the floppy, mount it with &man.mount.msdos.8; (in 4.X and earlier releases) or &man.mount.msdosfs.8; (in 5.0 or newer releases). One can also use mtools from the ports collection. Creating and Using Data Tapes tape media The major tape media are the 4mm, 8mm, QIC, mini-cartridge and DLT. 4mm (DDS: Digital Data Storage) tape media DDS (4mm) tapes tape media QIC tapes 4mm tapes are replacing QIC as the workstation backup media of choice. This trend accelerated greatly when Conner purchased Archive, a leading manufacturer of QIC drives, and then stopped production of QIC drives. 4mm drives are small and quiet but do not have the reputation for reliability that is enjoyed by 8mm drives. The cartridges are less expensive and smaller (3 x 2 x 0.5 inches, 76 x 51 x 12 mm) than 8mm cartridges. 4mm, like 8mm, has comparatively short head life for the same reason, both use helical scan. Data throughput on these drives starts ~150 kB/s, peaking at ~500 kB/s. Data capacity starts at 1.3 GB and ends at 2.0 GB. Hardware compression, available with most of these drives, approximately doubles the capacity. Multi-drive tape library units can have 6 drives in a single cabinet with automatic tape changing. Library capacities reach 240 GB. The DDS-3 standard now supports tape capacities up to 12 GB (or 24 GB compressed). 4mm drives, like 8mm drives, use helical-scan. All the benefits and drawbacks of helical-scan apply to both 4mm and 8mm drives. Tapes should be retired from use after 2,000 passes or 100 full backups. 8mm (Exabyte) tape media Exabyte (8mm) tapes 8mm tapes are the most common SCSI tape drives; they are the best choice of exchanging tapes. Nearly every site has an Exabyte 2 GB 8mm tape drive. 8mm drives are reliable, convenient and quiet. Cartridges are inexpensive and small (4.8 x 3.3 x 0.6 inches; 122 x 84 x 15 mm). One downside of 8mm tape is relatively short head and tape life due to the high rate of relative motion of the tape across the heads. Data throughput ranges from ~250 kB/s to ~500 kB/s. Data sizes start at 300 MB and go up to 7 GB. Hardware compression, available with most of these drives, approximately doubles the capacity. These drives are available as single units or multi-drive tape libraries with 6 drives and 120 tapes in a single cabinet. Tapes are changed automatically by the unit. Library capacities reach 840+ GB. The Exabyte Mammoth model supports 12 GB on one tape (24 GB with compression) and costs approximately twice as much as conventional tape drives. Data is recorded onto the tape using helical-scan, the heads are positioned at an angle to the media (approximately 6 degrees). The tape wraps around 270 degrees of the spool that holds the heads. The spool spins while the tape slides over the spool. The result is a high density of data and closely packed tracks that angle across the tape from one edge to the other. QIC tape media QIC-150 QIC-150 tapes and drives are, perhaps, the most common tape drive and media around. QIC tape drives are the least expensive serious backup drives. The downside is the cost of media. QIC tapes are expensive compared to 8mm or 4mm tapes, up to 5 times the price per GB data storage. But, if your needs can be satisfied with a half-dozen tapes, QIC may be the correct choice. QIC is the most common tape drive. Every site has a QIC drive of some density or another. Therein lies the rub, QIC has a large number of densities on physically similar (sometimes identical) tapes. QIC drives are not quiet. These drives audibly seek before they begin to record data and are clearly audible whenever reading, writing or seeking. QIC tapes measure (6 x 4 x 0.7 inches; 15.2 x 10.2 x 1.7 mm). Mini-cartridges, which also use 1/4" wide tape are discussed separately. Tape libraries and changers are not available. Data throughput ranges from ~150 kB/s to ~500 kB/s. Data capacity ranges from 40 MB to 15 GB. Hardware compression is available on many of the newer QIC drives. QIC drives are less frequently installed; they are being supplanted by DAT drives. Data is recorded onto the tape in tracks. The tracks run along the long axis of the tape media from one end to the other. The number of tracks, and therefore the width of a track, varies with the tape's capacity. Most if not all newer drives provide backward-compatibility at least for reading (but often also for writing). QIC has a good reputation regarding the safety of the data (the mechanics are simpler and more robust than for helical scan drives). Tapes should be retired from use after 5,000 backups. XXX* Mini-Cartridge DLT tape media DLT DLT has the fastest data transfer rate of all the drive types listed here. The 1/2" (12.5mm) tape is contained in a single spool cartridge (4 x 4 x 1 inches; 100 x 100 x 25 mm). The cartridge has a swinging gate along one entire side of the cartridge. The drive mechanism opens this gate to extract the tape leader. The tape leader has an oval hole in it which the drive uses to hook the tape. The take-up spool is located inside the tape drive. All the other tape cartridges listed here (9 track tapes are the only exception) have both the supply and take-up spools located inside the tape cartridge itself. Data throughput is approximately 1.5 MB/s, three times the throughput of 4mm, 8mm, or QIC tape drives. Data capacities range from 10 GB to 20 GB for a single drive. Drives are available in both multi-tape changers and multi-tape, multi-drive tape libraries containing from 5 to 900 tapes over 1 to 20 drives, providing from 50 GB to 9 TB of storage. With compression, DLT Type IV format supports up to 70 GB capacity. Data is recorded onto the tape in tracks parallel to the direction of travel (just like QIC tapes). Two tracks are written at once. Read/write head lifetimes are relatively long; once the tape stops moving, there is no relative motion between the heads and the tape. AIT tape media AIT AIT is a new format from Sony, and can hold up to 50 GB (with compression) per tape. The tapes contain memory chips which retain an index of the tape's contents. This index can be rapidly read by the tape drive to determine the position of files on the tape, instead of the several minutes that would be required for other tapes. Software such as SAMS:Alexandria can operate forty or more AIT tape libraries, communicating directly with the tape's memory chip to display the contents on screen, determine what files were backed up to which tape, locate the correct tape, load it, and restore the data from the tape. Libraries like this cost in the region of $20,000, pricing them a little out of the hobbyist market. Using a New Tape for the First Time The first time that you try to read or write a new, completely blank tape, the operation will fail. The console messages should be similar to: sa0(ncr1:4:0): NOT READY asc:4,1 sa0(ncr1:4:0): Logical unit is in process of becoming ready The tape does not contain an Identifier Block (block number 0). All QIC tape drives since the adoption of QIC-525 standard write an Identifier Block to the tape. There are two solutions: mt fsf 1 causes the tape drive to write an Identifier Block to the tape. Use the front panel button to eject the tape. Re-insert the tape and dump data to the tape. dump will report DUMP: End of tape detected and the console will show: HARDWARE FAILURE info:280 asc:80,96. rewind the tape using: mt rewind. Subsequent tape operations are successful. Backups to Floppies Can I Use floppies for Backing Up My Data? backup floppies floppy disks Floppy disks are not really a suitable media for making backups as: The media is unreliable, especially over long periods of time. Backing up and restoring is very slow. They have a very limited capacity (the days of backing up an entire hard disk onto a dozen or so floppies has long since passed). However, if you have no other method of backing up your data then floppy disks are better than no backup at all. If you do have to use floppy disks then ensure that you use good quality ones. Floppies that have been lying around the office for a couple of years are a bad choice. Ideally use new ones from a reputable manufacturer. So How Do I Backup My Data to Floppies? The best way to backup to floppy disk is to use &man.tar.1; with the (multi volume) option, which allows backups to span multiple floppies. To backup all the files in the current directory and sub-directory use this (as root): &prompt.root; tar Mcvf /dev/fd0 * When the first floppy is full &man.tar.1; will prompt you to insert the next volume (because &man.tar.1; is media independent it refers to volumes; in this context it means floppy disk). Prepare volume #2 for /dev/fd0 and hit return: This is repeated (with the volume number incrementing) until all the specified files have been archived. Can I Compress My Backups? tar gzip compression Unfortunately, &man.tar.1; will not allow the option to be used for multi-volume archives. You could, of course, &man.gzip.1; all the files, &man.tar.1; them to the floppies, then &man.gunzip.1; the files again! How Do I Restore My Backups? To restore the entire archive use: &prompt.root; tar Mxvf /dev/fd0 There are two ways that you can use to restore only specific files. First, you can start with the first floppy and use: &prompt.root; tar Mxvf /dev/fd0 filename The utility &man.tar.1; will prompt you to insert subsequent floppies until it finds the required file. Alternatively, if you know which floppy the file is on then you can simply insert that floppy and use the same command as above. Note that if the first file on the floppy is a continuation from the previous one then &man.tar.1; will warn you that it cannot restore it, even if you have not asked it to! Backup Basics backup software and basics The three major backup programs are &man.dump.8;, &man.tar.1;, and &man.cpio.1;. Dump and Restore backup software dump / restore dump restore The traditional Unix backup programs are dump and restore. They operate on the drive as a collection of disk blocks, below the abstractions of files, links and directories that are created by the file systems. dump backs up an entire file system on a device. It is unable to backup only part of a file system or a directory tree that spans more than one file system. dump does not write files and directories to tape, but rather writes the raw data blocks that comprise files and directories. If you use dump on your root directory, you would not back up /home, /usr or many other directories since these are typically mount points for other file systems or symbolic links into those file systems. dump has quirks that remain from its early days in Version 6 of AT&T Unix (circa 1975). The default parameters are suitable for 9-track tapes (6250 bpi), not the high-density media available today (up to 62,182 ftpi). These defaults must be overridden on the command line to utilize the capacity of current tape drives. .rhosts It is also possible to backup data across the network to a tape drive attached to another computer with rdump and rrestore. Both programs rely upon rcmd and ruserok to access the remote tape drive. Therefore, the user performing the backup must be listed in the .rhosts file on the remote computer. The arguments to rdump and rrestore must be suitable to use on the remote computer. When rdumping from a FreeBSD computer to an Exabyte tape drive connected to a Sun called komodo, use: &prompt.root; /sbin/rdump 0dsbfu 54000 13000 126 komodo:/dev/nsa8 /dev/da0a 2>&1 Beware: there are security implications to allowing .rhosts authentication. Evaluate your situation carefully. It is also possible to use dump and restore in a more secure fashion over ssh. Using <command>dump</command> over <application>ssh</application> &prompt.root; /sbin/dump -0uan -f - /usr | gzip -2 | ssh1 -c blowfish \ targetuser@targetmachine.example.com dd of=/mybigfiles/dump-usr-l0.gz <command>tar</command> backup software tar &man.tar.1; also dates back to Version 6 of AT&T Unix (circa 1975). tar operates in cooperation with the file system; tar writes files and directories to tape. tar does not support the full range of options that are available from &man.cpio.1;, but tar does not require the unusual command pipeline that cpio uses. tar Most versions of tar do not support backups across the network. The GNU version of tar, which FreeBSD utilizes, supports remote devices using the same syntax as rdump. To tar to an Exabyte tape drive connected to a Sun called komodo, use: &prompt.root; /usr/bin/tar cf komodo:/dev/nsa8 . 2>&1 For versions without remote device support, you can use a pipeline and rsh to send the data to a remote tape drive. &prompt.root; tar cf - . | rsh hostname dd of=tape-device obs=20b If you are worried about the security of backing up over a network you should use the ssh command instead of rsh. <command>cpio</command> backup software cpio &man.cpio.1; is the original Unix file interchange tape program for magnetic media. cpio has options (among many others) to perform byte-swapping, write a number of different archive formats, and pipe the data to other programs. This last feature makes cpio an excellent choice for installation media. cpio does not know how to walk the directory tree and a list of files must be provided through stdin. cpio cpio does not support backups across the network. You can use a pipeline and rsh to send the data to a remote tape drive. &prompt.root; for f in directory_list; do find $f >> backup.list done &prompt.root; cpio -v -o --format=newc < backup.list | ssh user@host "cat > backup_device" Where directory_list is the list of directories you want to back up, user@host is the user/hostname combination that will be performing the backups, and backup_device is where the backups should be written to (e.g., /dev/nsa0). <command>pax</command> backup software pax pax POSIX IEEE &man.pax.1; is IEEE/POSIX's answer to tar and cpio. Over the years the various versions of tar and cpio have gotten slightly incompatible. So rather than fight it out to fully standardize them, POSIX created a new archive utility. pax attempts to read and write many of the various cpio and tar formats, plus new formats of its own. Its command set more resembles cpio than tar. <application>Amanda</application> backup software Amanda Amanda Amanda (Advanced Maryland Network Disk Archiver) is a client/server backup system, rather than a single program. An Amanda server will backup to a single tape drive any number of computers that have Amanda clients and a network connection to the Amanda server. A common problem at sites with a number of large disks is that the length of time required to backup to data directly to tape exceeds the amount of time available for the task. Amanda solves this problem. Amanda can use a holding disk to backup several file systems at the same time. Amanda creates archive sets: a group of tapes used over a period of time to create full backups of all the file systems listed in Amanda's configuration file. The archive set also contains nightly incremental (or differential) backups of all the file systems. Restoring a damaged file system requires the most recent full backup and the incremental backups. The configuration file provides fine control of backups and the network traffic that Amanda generates. Amanda will use any of the above backup programs to write the data to tape. Amanda is available as either a port or a package, it is not installed by default. Do Nothing Do nothing is not a computer program, but it is the most widely used backup strategy. There are no initial costs. There is no backup schedule to follow. Just say no. If something happens to your data, grin and bear it! If your time and your data is worth little to nothing, then Do nothing is the most suitable backup program for your computer. But beware, Unix is a useful tool, you may find that within six months you have a collection of files that are valuable to you. Do nothing is the correct backup method for /usr/obj and other directory trees that can be exactly recreated by your computer. An example is the files that comprise the HTML or PostScript version of this Handbook. These document formats have been created from SGML input files. Creating backups of the HTML or PostScript files is not necessary. The SGML files are backed up regularly. Which Backup Program Is Best? LISA &man.dump.8; Period. Elizabeth D. Zwicky torture tested all the backup programs discussed here. The clear choice for preserving all your data and all the peculiarities of Unix file systems is dump. Elizabeth created file systems containing a large variety of unusual conditions (and some not so unusual ones) and tested each program by doing a backup and restore of those file systems. The peculiarities included: files with holes, files with holes and a block of nulls, files with funny characters in their names, unreadable and unwritable files, devices, files that change size during the backup, files that are created/deleted during the backup and more. She presented the results at LISA V in Oct. 1991. See torture-testing Backup and Archive Programs. Emergency Restore Procedure Before the Disaster There are only four steps that you need to perform in preparation for any disaster that may occur. disklabel First, print the disklabel from each of your disks (e.g. disklabel da0 | lpr), your file system table (/etc/fstab) and all boot messages, two copies of each. fix-it floppies Second, determine that the boot and fix-it floppies (boot.flp and fixit.flp) have all your devices. The easiest way to check is to reboot your machine with the boot floppy in the floppy drive and check the boot messages. If all your devices are listed and functional, skip on to step three. Otherwise, you have to create two custom bootable floppies which have a kernel that can mount all of your disks and access your tape drive. These floppies must contain: fdisk, disklabel, newfs, mount, and whichever backup program you use. These programs must be statically linked. If you use dump, the floppy must contain restore. Third, create backup tapes regularly. Any changes that you make after your last backup may be irretrievably lost. Write-protect the backup tapes. Fourth, test the floppies (either boot.flp and fixit.flp or the two custom bootable floppies you made in step two.) and backup tapes. Make notes of the procedure. Store these notes with the bootable floppy, the printouts and the backup tapes. You will be so distraught when restoring that the notes may prevent you from destroying your backup tapes (How? In place of tar xvf /dev/sa0, you might accidentally type tar cvf /dev/sa0 and over-write your backup tape). For an added measure of security, make bootable floppies and two backup tapes each time. Store one of each at a remote location. A remote location is NOT the basement of the same office building. A number of firms in the World Trade Center learned this lesson the hard way. A remote location should be physically separated from your computers and disk drives by a significant distance. A Script for Creating a Bootable Floppy /mnt/sbin/init gzip -c -best /sbin/fsck > /mnt/sbin/fsck gzip -c -best /sbin/mount > /mnt/sbin/mount gzip -c -best /sbin/halt > /mnt/sbin/halt gzip -c -best /sbin/restore > /mnt/sbin/restore gzip -c -best /bin/sh > /mnt/bin/sh gzip -c -best /bin/sync > /mnt/bin/sync cp /root/.profile /mnt/root cp -f /dev/MAKEDEV /mnt/dev chmod 755 /mnt/dev/MAKEDEV chmod 500 /mnt/sbin/init chmod 555 /mnt/sbin/fsck /mnt/sbin/mount /mnt/sbin/halt chmod 555 /mnt/bin/sh /mnt/bin/sync chmod 6555 /mnt/sbin/restore # # create the devices nodes # cd /mnt/dev ./MAKEDEV std ./MAKEDEV da0 ./MAKEDEV da1 ./MAKEDEV da2 ./MAKEDEV sa0 ./MAKEDEV pty0 cd / # # create minimum file system table # cat > /mnt/etc/fstab < /mnt/etc/passwd < /mnt/etc/master.passwd < After the Disaster The key question is: did your hardware survive? You have been doing regular backups so there is no need to worry about the software. If the hardware has been damaged. First, replace those parts that have been damaged. If your hardware is okay, check your floppies. If you are using a custom boot floppy, boot single-user (type -s at the boot: prompt). Skip the following paragraph. If you are using the boot.flp and fixit.flp floppies, keep reading. Insert the boot.flp floppy in the first floppy drive and boot the computer. The original install menu will be displayed on the screen. Select the Fixit--Repair mode with CDROM or floppy. option. Insert the fixit.flp when prompted. restore and the other programs that you need are located in /mnt2/stand. Recover each file system separately. mount root partition disklabel newfs Try to mount (e.g. mount /dev/da0a /mnt) the root partition of your first disk. If the disklabel was damaged, use disklabel to re-partition and label the disk to match the label that you printed and saved. Use newfs to re-create the file systems. Re-mount the root partition of the floppy read-write (mount -u -o rw /mnt). Use your backup program and backup tapes to recover the data for this file system (e.g. restore vrf /dev/sa0). Unmount the file system (e.g. umount /mnt). Repeat for each file system that was damaged. Once your system is running, backup your data onto new tapes. Whatever caused the crash or data loss may strike again. Another hour spent now may save you from further distress later. * I did not prepare for the Disaster, What Now? ]]> Marc Fonvieille Reorganized and enhanced by Network, Memory, and File-Backed File Systems virtual disks disks virtual Aside from the disks you physically insert into your computer: floppies, CDs, hard drives, and so forth; other forms of disks are understood by FreeBSD - the virtual disks. NFS Coda disks memory These include network file systems such as the Network File System and Coda, memory-based file systems and file-backed file systems. According to the FreeBSD version you run, you will have to use different tools for creation and use of file-backed and memory-based file systems. The FreeBSD 4.X users will have to use &man.MAKEDEV.8; to create the required devices. FreeBSD 5.0 and later use &man.devfs.5; to allocate device nodes transparently for the user. File-Backed File System under FreeBSD 4.X disks file-backed (4.X) The utility &man.vnconfig.8; configures and enables vnode pseudo-disk devices. A vnode is a representation of a file, and is the focus of file activity. This means that &man.vnconfig.8; uses files to create and operate a file system. One possible use is the mounting of floppy or CD images kept in files. To use &man.vnconfig.8;, you need &man.vn.4; support in your kernel configuration file: pseudo-device vn To mount an existing file system image: Using vnconfig to mount an Existing File System Image under FreeBSD 4.X &prompt.root; vnconfig vn0 diskimage &prompt.root; mount /dev/vn0c /mnt To create a new file system image with &man.vnconfig.8;: Creating a New File-Backed Disk with <command>vnconfig</command> &prompt.root; dd if=/dev/zero of=newimage bs=1k count=5k 5120+0 records in 5120+0 records out &prompt.root; vnconfig -s labels -c vn0 newimage &prompt.root; disklabel -r -w vn0 auto &prompt.root; newfs vn0c Warning: 2048 sector(s) in last cylinder unallocated /dev/vn0c: 10240 sectors in 3 cylinders of 1 tracks, 4096 sectors 5.0MB in 1 cyl groups (16 c/g, 32.00MB/g, 1280 i/g) super-block backups (for fsck -b #) at: 32 &prompt.root; mount /dev/vn0c /mnt &prompt.root; df /mnt Filesystem 1K-blocks Used Avail Capacity Mounted on /dev/vn0c 4927 1 4532 0% /mnt File-Backed File System under FreeBSD 5.X disks file-backed (5.X) The utility &man.mdconfig.8; is used to configure and enable memory disks, &man.md.4;, under FreeBSD 5.X. To use &man.mdconfig.8;, you have to load &man.md.4; module or to add the support in your kernel configuration file: device md The &man.mdconfig.8; command supports three kinds of memory backed virtual disks: memory disks allocated with - &man.malloc.9;, memory disks using a file or swapspace as - backingstore. One possible use is the mounting of floppy + &man.malloc.9;, memory disks using a file or swap space as + backing. One possible use is the mounting of floppy or CD images kept in files. To mount an existing file system image: Using <command>mdconfig</command> to mount an Existing File System Image under FreeBSD 5.X &prompt.root; mdconfig -a -t vnode -f diskimage -u 0 &prompt.root; mount /dev/md0c /mnt To create a new file system image with &man.mdconfig.8;: Creating a New File-Backed Disk with <command>mdconfig</command> &prompt.root; dd if=/dev/zero of=newimage bs=1k count=5k 5120+0 records in 5120+0 records out &prompt.root; mdconfig -a -t vnode -f newimage -u 0 &prompt.root; disklabel -r -w md0 auto &prompt.root; newfs md0c /dev/md0c: 5.0MB (10240 sectors) block size 16384, fragment size 2048 using 4 cylinder groups of 1.27MB, 81 blks, 256 inodes. super-block backups (for fsck -b #) at: 32, 2624, 5216, 7808 &prompt.root; mount /dev/md0c /mnt &prompt.root; df /mnt Filesystem 1K-blocks Used Avail Capacity Mounted on /dev/md0c 4846 2 4458 0% /mnt If you do not specify the unit number with the option, &man.mdconfig.8; will use the &man.md.4; automatic allocation to select an unused device. The name of the allocated unit will be output on stdout like md4. For more details about &man.mdconfig.8;, please refer to the manual page. The utility &man.mdconfig.8; is very useful, however it asks many command lines to create a file-backed file system. FreeBSD 5.0 also comes with a tool called &man.mdmfs.8;, this program configures a &man.md.4; disk using &man.mdconfig.8;, puts a UFS file system on it using &man.newfs.8;, and mounts it using &man.mount.8;. For example, if you want to create and mount the same file system image as above, simply type the following: &prompt.root; dd if=/dev/zero of=newimage bs=1k count=5k 5120+0 records in 5120+0 records in 5120+0 records out &prompt.root; mdmfs -F newimage -s 5m md0 /mnt &prompt.root; df /mnt Filesystem 1K-blocks Used Avail Capacity Mounted on /dev/md0 4846 2 4458 0% /mnt If you use the option without unit number, &man.mdmfs.8; will use &man.md.4; auto-unit feature to automatically select an unused device. For more details about &man.mdmfs.8;, please refer to the manual page. Memory-Based File System under FreeBSD 4.X disks memory file system (4.X) The &man.md.4; driver is a simple, efficient means to create memory file systems under FreeBSD 4.X. &man.malloc.9; is used to allocate the memory. Simply take a file system you have prepared with, for example, &man.vnconfig.8;, and: md Memory Disk under FreeBSD 4.X &prompt.root; dd if=newimage of=/dev/md0 5120+0 records in 5120+0 records out &prompt.root; mount /dev/md0c /mnt &prompt.root; df /mnt Filesystem 1K-blocks Used Avail Capacity Mounted on /dev/md0c 4927 1 4532 0% /mnt For more details, please refer to &man.md.4; manual page. Memory-Based File System under FreeBSD 5.X disks memory file system (5.X) The same tools are used for memory-based and file-backed file systems: &man.mdconfig.8; or &man.mdmfs.8;. The storage for memory-based file system is allocated with &man.malloc.9;. Creating a New Memory-Based Disk with <command>mdconfig</command> &prompt.root; mdconfig -a -t malloc -s 5m -u 1 &prompt.root; newfs -U md1 /dev/md1: 5.0MB (10240 sectors) block size 16384, fragment size 2048 using 4 cylinder groups of 1.27MB, 81 blks, 256 inodes. with soft updates super-block backups (for fsck -b #) at: 32, 2624, 5216, 7808 &prompt.root; mount /dev/md1 /mnt &prompt.root; df /mnt Filesystem 1K-blocks Used Avail Capacity Mounted on /dev/md1 4846 2 4458 0% /mnt Creating a New Memory-Based Disk with <command>mdmfs</command> &prompt.root; mdmfs -M -s 5m md2 /mnt &prompt.root; df /mnt Filesystem 1K-blocks Used Avail Capacity Mounted on /dev/md2 4846 2 4458 0% /mnt Instead of using a &man.malloc.9; backed file system, it is possible to use swap, for that just replace with in the command line of &man.mdconfig.8;. The &man.mdmfs.8; utility by default (without ) creates a swap-based disk. For more details, please refer to &man.mdconfig.8; and &man.mdmfs.8; manual pages. Detaching a Memory Disk from the System disks detaching a memory disk When a memory-based or file-based file system is not used, you should release all resources to the system. The first thing to do is to unmount the file system, then use &man.mdconfig.8; to detach the disk from the system and release the resources. For example to detach and free all resources used by /dev/md4: &prompt.root; mdconfig -d -u 4 It is possible to list information about configured &man.md.4; devices in using the command mdconfig -l. For FreeBSD 4.X, &man.vnconfig.8; is used to detach the device. For example to detach and free all resources used by /dev/vn4: &prompt.root; vnconfig -u vn4 Tom Rhodes Contributed by File System Snapshots file systems snapshots FreeBSD 5.0 offers a new feature in conjunction with Soft Updates: File system snapshots. Snapshots allow a user to create images of specified file systems, and treat them as a file. Snapshot files must be created in the file system that the action is performed on, and a user may create no more than 20 snapshots per file system. Active snapshots are recorded in the superblock so they are persistent across unmount and remount operations along with system reboots. When a snapshot is no longer required, it can be removed with the standard &man.rm.1; command. Snapshots may be removed in any order, however all the used space may not be acquired because another snapshot will possibly claim some of the released blocks. During initial creation, the flag (see the &man.chflags.1; manual page) is set to ensure that even root cannot write to the snapshot. The &man.unlink.1; command makes an exception for snapshot files since it allows them to be removed with the flag set, so it is not necessary to clear the flag before removing a snapshot file. Snapshots are created with the &man.mount.8; command. To place a snapshot of /var in the file /var/snapshot/snap use the following command: &prompt.root; mount -u -o snapshot /var/snapshot/snap /var Once a snapshot has been created, they have several uses: Some administrators will use a snapshot file for backup purposes, because the snapshot can be transfered to CDs or tape. File integrity, &man.fsck.8; may be ran on the snapshot. Assuming that the file system was clean when it was mounted, you should always get a clean (and unchanging) result. This is essentially what the background &man.fsck.8; process does. Run the &man.dump.8; utility on the snapshot. A dump will be returned that is consistent with the file system and the timestamp of the snapshot. &man.dump.8; can also take a snapshot, create a dump image and then remove the snapshot in one command using the flag. &man.mount.8; the snapshot as a frozen image of the file system. To &man.mount.8; the snapshot /var/snapshot/snap run: &prompt.root; mdconfig -a -t vnode -f /var/snapshot/snap -u 4 &prompt.root; mount -r /dev/md4 /mnt You can now walk the hierarchy of your frozen /var file system mounted at /mnt. Everything will be in the same state it was during the snapshot creation time. The only exception is that any earlier snapshots will appear as zero length files. When the use of a snapshot has delimited, it can be unmounted with: &prompt.root; umount /mnt &prompt.root; mdconfig -d -u 4 For more information about and file system snapshots, including technical papers, you can visit Marshall Kirk McKusick's website at http://www.mckusick.com. File System Quotas accounting disk space disk quotas Quotas are an optional feature of the operating system that allow you to limit the amount of disk space and/or the number of files a user or members of a group may allocate on a per-file system basis. This is used most often on timesharing systems where it is desirable to limit the amount of resources any one user or group of users may allocate. This will prevent one user or group of users from consuming all of the available disk space. Configuring Your System to Enable Disk Quotas Before attempting to use disk quotas, it is necessary to make sure that quotas are configured in your kernel. This is done by adding the following line to your kernel configuration file: options QUOTA The stock GENERIC kernel does not have this enabled by default, so you will have to configure, build and install a custom kernel in order to use disk quotas. Please refer to for more information on kernel configuration. Next you will need to enable disk quotas in /etc/rc.conf. This is done by adding the line: enable_quotas="YES" disk quotas checking For finer control over your quota startup, there is an additional configuration variable available. Normally on bootup, the quota integrity of each file system is checked by the &man.quotacheck.8; program. The &man.quotacheck.8; facility insures that the data in the quota database properly reflects the data on the file system. This is a very time consuming process that will significantly affect the time your system takes to boot. If you would like to skip this step, a variable in /etc/rc.conf is made available for the purpose: check_quotas="NO" If you are running FreeBSD prior to 3.2-RELEASE, the configuration is simpler, and consists of only one variable. Set the following in your /etc/rc.conf: check_quotas="YES" Finally you will need to edit /etc/fstab to enable disk quotas on a per-file system basis. This is where you can either enable user or group quotas or both for all of your file systems. To enable per-user quotas on a file system, add the option to the options field in the /etc/fstab entry for the file system you want to enable quotas on. For example: /dev/da1s2g /home ufs rw,userquota 1 2 Similarly, to enable group quotas, use the option instead of . To enable both user and group quotas, change the entry as follows: /dev/da1s2g /home ufs rw,userquota,groupquota 1 2 By default, the quota files are stored in the root directory of the file system with the names quota.user and quota.group for user and group quotas respectively. See &man.fstab.5; for more information. Even though the &man.fstab.5; manual page says that you can specify an alternate location for the quota files, this is not recommended because the various quota utilities do not seem to handle this properly. At this point you should reboot your system with your new kernel. /etc/rc will automatically run the appropriate commands to create the initial quota files for all of the quotas you enabled in /etc/fstab, so there is no need to manually create any zero length quota files. In the normal course of operations you should not be required to run the &man.quotacheck.8;, &man.quotaon.8;, or &man.quotaoff.8; commands manually. However, you may want to read their manual pages just to be familiar with their operation. Setting Quota Limits disk quotas limits Once you have configured your system to enable quotas, verify that they really are enabled. An easy way to do this is to run: &prompt.root; quota -v You should see a one line summary of disk usage and current quota limits for each file system that quotas are enabled on. You are now ready to start assigning quota limits with the &man.edquota.8; command. You have several options on how to enforce limits on the amount of disk space a user or group may allocate, and how many files they may create. You may limit allocations based on disk space (block quotas) or number of files (inode quotas) or a combination of both. Each of these limits are further broken down into two categories: hard and soft limits. hard limit A hard limit may not be exceeded. Once a user reaches his hard limit he may not make any further allocations on the file system in question. For example, if the user has a hard limit of 500 blocks on a file system and is currently using 490 blocks, the user can only allocate an additional 10 blocks. Attempting to allocate an additional 11 blocks will fail. soft limit Soft limits, on the other hand, can be exceeded for a limited amount of time. This period of time is known as the grace period, which is one week by default. If a user stays over his or her soft limit longer than the grace period, the soft limit will turn into a hard limit and no further allocations will be allowed. When the user drops back below the soft limit, the grace period will be reset. The following is an example of what you might see when you run the &man.edquota.8; command. When the &man.edquota.8; command is invoked, you are placed into the editor specified by the EDITOR environment variable, or in the vi editor if the EDITOR variable is not set, to allow you to edit the quota limits. &prompt.root; edquota -u test Quotas for user test: /usr: blocks in use: 65, limits (soft = 50, hard = 75) inodes in use: 7, limits (soft = 50, hard = 60) /usr/var: blocks in use: 0, limits (soft = 50, hard = 75) inodes in use: 0, limits (soft = 50, hard = 60) You will normally see two lines for each file system that has quotas enabled. One line for the block limits, and one line for inode limits. Simply change the value you want updated to modify the quota limit. For example, to raise this user's block limit from a soft limit of 50 and a hard limit of 75 to a soft limit of 500 and a hard limit of 600, change: /usr: blocks in use: 65, limits (soft = 50, hard = 75) to: /usr: blocks in use: 65, limits (soft = 500, hard = 600) The new quota limits will be in place when you exit the editor. Sometimes it is desirable to set quota limits on a range of UIDs. This can be done by use of the option on the &man.edquota.8; command. First, assign the desired quota limit to a user, and then run edquota -p protouser startuid-enduid. For example, if user test has the desired quota limits, the following command can be used to duplicate those quota limits for UIDs 10,000 through 19,999: &prompt.root; edquota -p test 10000-19999 For more information see &man.edquota.8; manual page. Checking Quota Limits and Disk Usage disk quotas checking You can use either the &man.quota.1; or the &man.repquota.8; commands to check quota limits and disk usage. The &man.quota.1; command can be used to check individual user or group quotas and disk usage. A user may only examine his own quota, and the quota of a group he is a member of. Only the super-user may view all user and group quotas. The &man.repquota.8; command can be used to get a summary of all quotas and disk usage for file systems with quotas enabled. The following is some sample output from the quota -v command for a user that has quota limits on two file systems. Disk quotas for user test (uid 1002): Filesystem blocks quota limit grace files quota limit grace /usr 65* 50 75 5days 7 50 60 /usr/var 0 50 75 0 50 60 grace period On the /usr file system in the above example, this user is currently 15 blocks over the soft limit of 50 blocks and has 5 days of the grace period left. Note the asterisk * which indicates that the user is currently over his quota limit. Normally file systems that the user is not using any disk space on will not show up in the output from the &man.quota.1; command, even if he has a quota limit assigned for that file system. The option will display those file systems, such as the /usr/var file system in the above example. Quotas over NFS NFS Quotas are enforced by the quota subsystem on the NFS server. The &man.rpc.rquotad.8; daemon makes quota information available to the &man.quota.1; command on NFS clients, allowing users on those machines to see their quota statistics. Enable rpc.rquotad in /etc/inetd.conf like so: rquotad/1 dgram rpc/udp wait root /usr/libexec/rpc.rquotad rpc.rquotad Now restart inetd: &prompt.root; kill -HUP `cat /var/run/inetd.pid` Lucky Green Contributed by
shamrock@cypherpunks.to
Encrypting Disk Partitions disks encrypting FreeBSD offers excellent online protections against unauthorized data access. File permissions and Mandatory Access Control (MAC) (see ) help prevent unauthorized third-parties from accessing data while the operating system is active and the computer is powered up. However, the permissions enforced by the operating system are irrelevant if an attacker has physical access to a computer and can simply move the computer's hard drive to another system to copy and analyze the sensitive data. Regardless of how an attacker may have come into possession of a hard drive or powered-down computer, GEOM Based Disk Encryption (gbde) can protect the data on the computer's file systems against even highly-motivated attackers with significant resources. Unlike cumbersome encryption methods that encrypt only individual files, gbde transparently encrypts entire file systems. No cleartext ever touches the hard drive's platter. Enabling gbde in the Kernel Become root Configuring gbde requires super-user privileges. &prompt.user; su - Password: Verify the operating system version &man.gbde.4; requires FreeBSD 5.0 or higher. &prompt.root; uname -r 5.0-RELEASE Add &man.gbde.4; support to the kernel configuration file Using your favorite text editor, add the following line to your kernel configuration file: options GEOM_BDE Configure, recompile, and install the FreeBSD kernel. This process is described in . Reboot into the new kernel. Preparing the Encrypted Hard Drive The following example assumes that you are adding a new hard drive to your system that will hold a single encrypted partition. This partition will be mounted as /private. gbde can also be used to encrypt /home and /var/mail, but this requires more complex instructions which exceed the scope of this introduction. Add the new hard drive Install the new drive to the system as explained in . For the purposes of this example, a new hard drive partition has been added as /dev/ad4s1c. The /dev/ad0s1* devices represent existing standard FreeBSD partitions on the example system. &prompt.root; ls /dev/ad* /dev/ad0 /dev/ad0s1b /dev/ad0s1e /dev/ad4s1 /dev/ad0s1 /dev/ad0s1c /dev/ad0s1f /dev/ad4s1c /dev/ad0s1a /dev/ad0s1d /dev/ad4 Create a directory to hold GBDE lock files &prompt.root; mkdir /etc/gbde The gbde lock file contains information that gbde requires to access encrypted partitions. Without access to the lock file, gbde will not be able to decrypt the data contained in the encrypted partition without significant manual intervention which is not supported by the software. Each encrypted partition uses a separate lock file. Initialize the gbde partition A gbde partition must be initialized before it can be used. This initialization needs to be performed only once: &prompt.root; gbde init /dev/ad4s1c -i -L /etc/gbde/ad4s1c &man.gbde.8; will open your editor, permitting you to set various configuration options in a template. For use with UFS1 or UFS2, set the sector_size to 2048: $FreeBSD: src/sbin/gbde/template.txt,v 1.1 2002/10/20 11:16:13 phk Exp $ # # Sector size is the smallest unit of data which can be read or written. # Making it too small decreases performance and decreases available space. # Making it too large may prevent filesystems from working. 512 is the # minimum and always safe. For UFS, use the fragment size # sector_size = 2048 [...] &man.gbde.8; will ask you twice to type the passphrase that should be used to secure the data. The passphrase must be the same both times. gbde's ability to protect your data depends entirely on the quality of the passphrase that you choose. For tips on how to select a secure passphrase that is easy to remember, see the Diceware Passphrase website. The gbde init command creates a lock file for your gbde partition that in this example is stored as /etc/gbde/ad4s1c. gbde lock files must be backed up together with the contents of any encrypted partitions. While deleting a lock file alone cannot prevent a determined attacker from decrypting a gbde partition, without the lock file, the legitimate owner will be unable to access the data on the encrypted partition without a significant amount of work that is totally unsupported by &man.gbde.8; and its designer. Attach the encrypted partition to the kernel &prompt.root; gbde attach /dev/ad4s1c -l /etc/gbde/ad4s1c You will be asked to provide the passphrase that you selected during the initialization of the encrypted partition. The new encrypted device will show up in /dev as /dev/device_name.bde: &prompt.root; ls /dev/ad* /dev/ad0 /dev/ad0s1b /dev/ad0s1e /dev/ad4s1 /dev/ad0s1 /dev/ad0s1c /dev/ad0s1f /dev/ad4s1c /dev/ad0s1a /dev/ad0s1d /dev/ad4 /dev/ad4s1c.bde Create a file system on the encrypted device Once the encrypted device has been attached to the kernel, you can create a file system on the device. To create a file system on the encrypted device, use &man.newfs.8;. Since it is much faster to initialize a new UFS2 file system than it is to initialize the old UFS1 file system, using &man.newfs.8; with the option is recommended. The option is the default with &os; 5.1-RELEASE and later. &prompt.root; newfs -U -O2 /dev/ad4s1c.bde The &man.newfs.8; command must be performed on an attached gbde partition which is identified by a *.bde extension to the device name. Mount the encrypted partition Create a mount point for the encrypted file system. &prompt.root; mkdir /private Mount the encrypted file system. &prompt.root; mount /dev/ad4s1c.bde /private Verify that the encrypted file system is available The encrypted file system should now be visible to &man.df.1; and be available for use. &prompt.user; df -H Filesystem Size Used Avail Capacity Mounted on /dev/ad0s1a 1037M 72M 883M 8% / /devfs 1.0K 1.0K 0B 100% /dev /dev/ad0s1f 8.1G 55K 7.5G 0% /home /dev/ad0s1e 1037M 1.1M 953M 0% /tmp /dev/ad0s1d 6.1G 1.9G 3.7G 35% /usr /dev/ad4s1c.bde 150G 4.1K 138G 0% /private Mounting Existing Encrypted File Systems After each boot, any encrypted file systems must be re-attached to the kernel, checked for errors, and mounted, before the file systems can be used. The required commands must be executed as user root. Attach the gbde partition to the kernel &prompt.root; gbde attach /dev/ad4s1c -l /etc/gbde/ad4s1c You will be asked to provide the passphrase that you selected during initialization of the encrypted gbde partition. Check the file system for errors Since encrypted file systems cannot yet be listed in /etc/fstab for automatic mounting, the file systems must be checked for errors by running &man.fsck.8; manually before mounting. &prompt.root; fsck -p -t ffs /dev/ad4s1c.bde Mount the encrypted file system &prompt.root; mount /dev/ad4s1c.bde /private The encrypted file system is now available for use. Automatically Mounting Encrypted Partitions It is possible to create a script to automatically attach, check, and mount an encrypted partition, but for security reasons the script should not contain the &man.gbde.8; password. Instead, it is recommended that such scripts be run manually while providing the password via the console or &man.ssh.1;. Cryptographic Protections Employed by gbde &man.gbde.8; encrypts the sector payload using 128-bit AES in CBC mode. Each sector on the disk is encrypted with a different AES key. For more information on gbde's cryptographic design, including how the sector keys are derived from the user-supplied passphrase, see &man.gbde.4;. Compatibility Issues &man.sysinstall.8; is incompatible with gbde-encrypted devices. All *.bde devices must be detached from the kernel before starting &man.sysinstall.8; or it will crash during its initial probing for devices. To detach the encrypted device used in our example, use the following command: &prompt.root; gbde detach /dev/ad4s1c
diff --git a/en_US.ISO8859-1/books/handbook/linuxemu/chapter.sgml b/en_US.ISO8859-1/books/handbook/linuxemu/chapter.sgml index dab393493f..3b5099a70d 100644 --- a/en_US.ISO8859-1/books/handbook/linuxemu/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/linuxemu/chapter.sgml @@ -1,3097 +1,3097 @@ Jim Mock Restructured and parts updated by Brian N. Handy Originally contributed by Rich Murphey Linux Binary Compatibility Synopsis Linux binary compatibility binary compatibility Linux FreeBSD provides binary compatibility with several other Unix-like operating systems, including Linux. At this point, you may be asking yourself why exactly, does FreeBSD need to be able to run Linux binaries? The answer to that question is quite simple. Many companies and developers develop only for Linux, since it is the latest hot thing in the computing world. That leaves the rest of us FreeBSD users bugging these same companies and developers to put out native FreeBSD versions of their applications. The problem is, that most of these companies do not really realize how many people would use their product if there were FreeBSD versions too, and most continue to only develop for Linux. So what is a FreeBSD user to do? This is where the Linux binary compatibility of FreeBSD comes into play. In a nutshell, the compatibility allows FreeBSD users to run about 90% of all Linux applications without modification. This includes applications such as Star Office, the Linux version of Netscape, Adobe Acrobat, RealPlayer 5 and 7, VMWare, Oracle, WordPerfect, Doom, Quake, and more. It is also reported that in some situations, Linux binaries perform better on FreeBSD than they do under Linux. Linux /proc file system There are, however, some Linux-specific operating system features that are not supported under FreeBSD. Linux binaries will not work on FreeBSD if they overly use the Linux /proc file system (which is different from FreeBSD's /proc file system), or i386-specific calls, such as enabling virtual 8086 mode. After reading this chapter, you will know: How to enable Linux binary compatibility on your system. How to install additional Linux shared libraries. How to install Linux applications on your FreeBSD system. The implementation details of Linux compatibility in FreeBSD. Before reading this chapter, you should: Know how to install additional third-party software (). Installation KLD (kernel loadable object) Linux binary compatibility is not turned on by default. The easiest way to enable this functionality is to load the linux KLD object (Kernel LoaDable object). You can load this module by simply typing linux at the command prompt. If you would like Linux compatibility to always be enabled, then you should add the following line to /etc/rc.conf: linux_enable="YES" The &man.kldstat.8; command can be used to verify that the KLD is loaded: &prompt.user; kldstat Id Refs Address Size Name 1 2 0xc0100000 16bdb8 kernel 7 1 0xc24db000 d000 linux.ko kernel options LINUX If for some reason you do not want to or cannot load the KLD, then you may statically link Linux binary compatibility into the kernel by adding options LINUX to your kernel configuration file. Then install your new kernel as described in . Installing Linux Runtime Libraries Linux installing Linux libraries This can be done one of two ways, either by using the linux_base port, or by installing them manually. Installing Using the linux_base Port ports collection This is by far the easiest method to use when installing the runtime libraries. It is just like installing any other port from the ports collection. Simply do the following: &prompt.root; cd /usr/ports/emulators/linux_base &prompt.root; make install distclean You should now have working Linux binary compatibility. Some programs may complain about incorrect minor versions of the system libraries. In general, however, this does not seem to be a problem. Installing Libraries Manually If you do not have the ports collection installed, you can install the libraries by hand instead. You will need the Linux shared libraries that the program depends on and the runtime linker. Also, you will need to create a shadow root directory, /compat/linux, for Linux libraries on your FreeBSD system. Any shared libraries opened by Linux programs run under FreeBSD will look in this tree first. So, if a Linux program loads, for example, /lib/libc.so, FreeBSD will first try to open /compat/linux/lib/libc.so, and if that does not exist, it will then try /lib/libc.so. Shared libraries should be installed in the shadow tree /compat/linux/lib rather than the paths that the Linux ld.so reports. Generally, you will need to look for the shared libraries that Linux binaries depend on only the first few times that you install a Linux program on your FreeBSD system. After a while, you will have a sufficient set of Linux shared libraries on your system to be able to run newly imported Linux binaries without any extra work. How to Install Additional Shared Libraries shared libraries What if you install the linux_base port and your application still complains about missing shared libraries? How do you know which shared libraries Linux binaries need, and where to get them? Basically, there are 2 possibilities (when following these instructions you will need to be root on your FreeBSD system). If you have access to a Linux system, see what shared libraries the application needs, and copy them to your FreeBSD system. Look at the following example: Let us assume you used FTP to get the Linux binary of Doom, and put it on a Linux system you have access to. You then can check which shared libraries it needs by running ldd linuxdoom, like so: &prompt.user; ldd linuxdoom libXt.so.3 (DLL Jump 3.1) => /usr/X11/lib/libXt.so.3.1.0 libX11.so.3 (DLL Jump 3.1) => /usr/X11/lib/libX11.so.3.1.0 libc.so.4 (DLL Jump 4.5pl26) => /lib/libc.so.4.6.29 symbolic links You would need to get all the files from the last column, and put them under /compat/linux, with the names in the first column as symbolic links pointing to them. This means you eventually have these files on your FreeBSD system: /compat/linux/usr/X11/lib/libXt.so.3.1.0 /compat/linux/usr/X11/lib/libXt.so.3 -> libXt.so.3.1.0 /compat/linux/usr/X11/lib/libX11.so.3.1.0 /compat/linux/usr/X11/lib/libX11.so.3 -> libX11.so.3.1.0 /compat/linux/lib/libc.so.4.6.29 /compat/linux/lib/libc.so.4 -> libc.so.4.6.29
Note that if you already have a Linux shared library with a matching major revision number to the first column of the ldd output, you will not need to copy the file named in the last column to your system, the one you already have should work. It is advisable to copy the shared library anyway if it is a newer version, though. You can remove the old one, as long as you make the symbolic link point to the new one. So, if you have these libraries on your system: /compat/linux/lib/libc.so.4.6.27 /compat/linux/lib/libc.so.4 -> libc.so.4.6.27 and you find a new binary that claims to require a later version according to the output of ldd: libc.so.4 (DLL Jump 4.5pl26) -> libc.so.4.6.29 If it is only one or two versions out of date in the in the trailing digit then do not worry about copying /lib/libc.so.4.6.29 too, because the program should work fine with the slightly older version. However, if you like, you can decide to replace the libc.so anyway, and that should leave you with: /compat/linux/lib/libc.so.4.6.29 /compat/linux/lib/libc.so.4 -> libc.so.4.6.29
The symbolic link mechanism is only needed for Linux binaries. The FreeBSD runtime linker takes care of looking for matching major revision numbers itself and you do not need to worry about it.
Installing Linux ELF Binaries Linux ELF binaries ELF binaries sometimes require an extra step of branding. If you attempt to run an unbranded ELF binary, you will get an error message like the following: &prompt.user; ./my-linux-elf-binary ELF binary type not known Abort To help the FreeBSD kernel distinguish between a FreeBSD ELF binary from a Linux binary, use the &man.brandelf.1; utility. &prompt.user; brandelf -t Linux my-linux-elf-binary GNU toolchain The GNU toolchain now places the appropriate branding information into ELF binaries automatically, so this step should become increasingly more rare in the future. Configuring the Hostname Resolver If DNS does not work or you get this message: resolv+: "bind" is an invalid keyword resolv+: "hosts" is an invalid keyword You will need to configure a /compat/linux/etc/host.conf file containing: order hosts, bind multi on The order here specifies that /etc/hosts is searched first and DNS is searched second. When /compat/linux/etc/host.conf is not installed, Linux applications find FreeBSD's /etc/host.conf and complain about the incompatible FreeBSD syntax. You should remove bind if you have not configured a name server using the /etc/resolv.conf file.
Murray Stokely Updated for Mathematica 4.X by Bojan Bistrovic Merged with work by Installing Mathematica applications Mathematica This document describes the process of installing the Linux version of Mathematica 4.X onto a FreeBSD system. The Linux version of Mathematica runs perfectly under FreeBSD however the binaries shipped by Wolfram need to be branded so that FreeBSD knows to use the Linux ABI to execute them. The Linux version of Mathematica or Mathematica for Students can be ordered directly from Wolfram at . Branding the Linux Binaries The Linux binaries are located in the Unix directory of the Mathematica CDROM distributed by Wolfram. You need to copy this directory tree to your local hard drive so that you can brand the Linux binaries with &man.brandelf.1; before running the installer: &prompt.root; mount /cdrom &prompt.root; cp -rp /cdrom/Unix/ /localdir/ &prompt.root; brandelf -t Linux /localdir/Files/SystemFiles/Kernel/Binaries/Linux/* &prompt.root; brandelf -t Linux /localdir/Files/SystemFiles/FrontEnd/Binaries/Linux/* &prompt.root; brandelf -t Linux /localdir/Files/SystemFiles/Installation/Binaries/Linux/* &prompt.root; brandelf -t Linux /localdir/Files/SystemFiles/Graphics/Binaries/Linux/* &prompt.root; brandelf -t Linux /localdir/Files/SystemFiles/Converters/Binaries/Linux/* &prompt.root; brandelf -t Linux /localdir/Files/SystemFiles/LicenseManager/Binaries/Linux/mathlm &prompt.root; cd /localdir/Installers/Linux/ &prompt.root; ./MathInstaller Alternatively, you can simply set the default ELF brand to Linux for all unbranded binaries with the command: &prompt.root; sysctl kern.fallback_elf_brand=3 This will make FreeBSD assume that unbranded ELF binaries use the Linux ABI and so you should be able to run the installer straight from the CDROM. Obtaining Your Mathematica Password Before you can run Mathematica you will have to obtain a password from Wolfram that corresponds to your machine ID. Ethernet MAC address Once you have installed the Linux compatibility runtime libraries and unpacked Mathematica you can obtain the machine ID by running the program mathinfo in the Install directory. This machine ID is based solely on the MAC address of your first Ethernet card. &prompt.root; cd /localdir/Files/SystemFiles/Installation/Binaries/Linux &prompt.root; mathinfo disco.example.com 7115-70839-20412 When you register with Wolfram, either by email, phone or fax, you will give them the machine ID and they will respond with a corresponding password consisting of groups of numbers. You can then enter this information when you attempt to run Mathematica for the first time exactly as you would for any other Mathematica platform. Running the Mathematica Frontend over a Network Mathematica uses some special fonts to display characters not present in any of the standard font sets (integrals, sums, Greek letters, etc.). The X protocol requires these fonts to be install locally. This means you will have to copy these fonts from the CDROM or from a host with Mathematica installed to your local machine. These fonts are normally stored in /cdrom/Unix/Files/SystemFiles/Fonts on the CDROM, or /usr/local/mathematica/SystemFiles/Fonts on your hard drive. The actual fonts are in the subdirectories Type1 and X. There are several ways to use them, as described below. The first way is to copy them into one of the existing font directories in /usr/X11R6/lib/X11/fonts. This will require editing the fonts.dir file, adding the font names to it, and changing the number of fonts on the first line. Alternatively, you should also just be able to run mkfontdir in the directory you have copied them to. The second way to do this is to copy the directories to /usr/X11R6/lib/X11/fonts: &prompt.root; cd /usr/X11R6/lib/X11/fonts &prompt.root; mkdir X &prompt.root; mkdir MathType1 &prompt.root; cd /cdrom/Unix/Files/SystemFiles/Fonts &prompt.root; cp X/* /usr/X11R6/lib/X11/fonts/X &prompt.root; cp Type1/* /usr/X11R6/lib/X11/fonts/MathType1 &prompt.root; cd /usr/X11R6/lib/X11/fonts/X &prompt.root; mkfontdir &prompt.root; cd ../MathType1 &prompt.root; mkfontdir Now add the new font directories to your font path: &prompt.root; xset fp+ /usr/X11R6/lib/X11/fonts/X &prompt.root; xset fp+ /usr/X11R6/lib/X11/fonts/MathType1 &prompt.root; xset fp rehash If you are using the XFree86 server, you can have these font directories loaded automatically by adding them to your XF86Config file. fonts If you do not already have a directory called /usr/X11R6/lib/X11/fonts/Type1, you can change the name of the MathType1 directory in the example above to Type1. Aaron Kaplan Contributed by Robert Getschmann Thanks to Installing Maple applications Maple Maple is a commercial mathematics program similar to Mathematica. You must purchase this software from and then register there for a license file. To install this software on FreeBSD, please follow these simple steps. Execute the INSTALL shell script from the product distribution. Choose the RedHat option when prompted by the installation program. A typical installation directory might be /usr/local/maple. If you have not done so, order a license for Maple from Maple Waterloo Software (http://register.maplesoft.com) and copy it to /usr/local/maple/license/license.dat. Install the FLEXlm license manager by running the INSTALL_LIC install shell script that comes with Maple. Specify the primary hostname for your machine for the license server. Patch the usr/local/maple/bin/maple.system.type file with the following: ----- snip ------------------ *** maple.system.type.orig Sun Jul 8 16:35:33 2001 --- maple.system.type Sun Jul 8 16:35:51 2001 *************** *** 72,77 **** --- 72,78 ---- # the IBM RS/6000 AIX case MAPLE_BIN="bin.IBM_RISC_UNIX" ;; + "FreeBSD"|\ "Linux") # the Linux/x86 case # We have two Linux implementations, one for Red Hat and ----- snip end of patch ----- Please note that after the "FreeBSD"|\ no other whitespace should be present. This patch instructs Maple to recognize FreeBSD as a type of Linux system. The bin/maple shell script calls the bin/maple.system.type shell script which in turn calls uname -a to find out the operating system name. Depending on the OS name it will find out which binaries to use. Start the license server. The following script, installed as /usr/local/etc/rc.d/lmgrd.sh is a convenient way to start up lmgrd: ----- snip ------------ #! /bin/sh PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/X11R6/bin PATH=${PATH}:/usr/local/maple/bin:/usr/local/maple/FLEXlm/UNIX/LINUX export PATH LICENSE_FILE=/usr/local/maple/license/license.dat LOG=/var/log/lmgrd.log case "$1" in start) lmgrd -c ${LICENSE_FILE} 2>> ${LOG} 1>&2 echo -n " lmgrd" ;; stop) lmgrd -c ${LICENSE_FILE} -x lmdown 2>> ${LOG} 1>&2 ;; *) echo "Usage: `basename $0` {start|stop}" 1>&2 exit 64 ;; esac exit 0 ----- snip ------------ Test-start maple: &prompt.user; cd /usr/local/maple/bin &prompt.user; ./xmaple You should be up and running. Make sure to write Maplesoft to let them know you would like a native FreeBSD version! Common Pitfalls The FLEXlm license manager can be a difficult tool to work with. Additional documentation on the subject can be found at . lmgrd is known to be very picky about the license file and to core dump if there are any problems. A correct license file should look like this: # ======================================================= # License File for UNIX Installations ("Pointer File") # ======================================================= SERVER chillig ANY #USE_SERVER VENDOR maplelmg FEATURE Maple maplelmg 2000.0831 permanent 1 XXXXXXXXXXXX \ PLATFORMS=i86_r ISSUER="Waterloo Maple Inc." \ ISSUED=11-may-2000 NOTICE=" Technische Universitat Wien" \ SN=XXXXXXXXX Serial number and key 'X''ed out. chillig is a hostname. Editing the license file works as long as you do not touch the FEATURE line (which is protected by the license key). Marcel Moolenaar Contributed by Installing Oracle applications Oracle Preface This document describes the process of installing Oracle 8.0.5 and Oracle 8.0.5.1 Enterprise Edition for Linux onto a FreeBSD machine. Installing the Linux Environment Make sure you have both linux_base and linux_devtools from the ports collection installed. These ports are added to the collection after the release of FreeBSD 3.2. If you are using FreeBSD 3.2 or an older version for that matter, update your ports collection. You may want to consider updating your FreeBSD version too. If you run into difficulties with linux_base-6.1 or linux_devtools-6.1 you may have to use version 5.2 of these packages. If you want to run the intelligent agent, you will also need to install the Red Hat Tcl package: tcl-8.0.3-20.i386.rpm. The general command for installing packages with the official RPM port is: &prompt.root; rpm -i --ignoreos --root /compat/linux --dbpath /var/lib/rpm package Installation of the package should not generate any errors. Creating the Oracle Environment Before you can install Oracle, you need to set up a proper environment. This document only describes what to do specially to run Oracle for Linux on FreeBSD, not what has been described in the Oracle installation guide. Kernel Tuning kernel tuning As described in the Oracle installation guide, you need to set the maximum size of shared memory. Do not use SHMMAX under FreeBSD. SHMMAX is merely calculated out of SHMMAXPGS and PGSIZE. Therefore define SHMMAXPGS. All other options can be used as described in the guide. For example: options SHMMAXPGS=10000 options SHMMNI=100 options SHMSEG=10 options SEMMNS=200 options SEMMNI=70 options SEMMSL=61 Set these options to suit your intended use of Oracle. Also, make sure you have the following options in your kernel config-file: options SYSVSHM #SysV shared memory options SYSVSEM #SysV semaphores options SYSVMSG #SysV interprocess communication Oracle Account Create an Oracle account just as you would create any other account. The Oracle account is special only that you need to give it a Linux shell. Add /compat/linux/bin/bash to /etc/shells and set the shell for the Oracle account to /compat/linux/bin/bash. Environment Besides the normal Oracle variables, such as ORACLE_HOME and ORACLE_SID you must set the following environment variables: Variable Value LD_LIBRARY_PATH $ORACLE_HOME/lib CLASSPATH $ORACLE_HOME/jdbc/lib/classes111.zip PATH /compat/linux/bin /compat/linux/sbin /compat/linux/usr/bin /compat/linux/usr/sbin /bin /sbin /usr/bin /usr/sbin /usr/local/bin $ORACLE_HOME/bin It is advised to set all the environment variables in .profile. A complete example is: ORACLE_BASE=/oracle; export ORACLE_BASE ORACLE_HOME=/oracle; export ORACLE_HOME LD_LIBRARY_PATH=$ORACLE_HOME/lib export LD_LIBRARY_PATH ORACLE_SID=ORCL; export ORACLE_SID ORACLE_TERM=386x; export ORACLE_TERM CLASSPATH=$ORACLE_HOME/jdbc/lib/classes111.zip export CLASSPATH PATH=/compat/linux/bin:/compat/linux/sbin:/compat/linux/usr/bin PATH=$PATH:/compat/linux/usr/sbin:/bin:/sbin:/usr/bin:/usr/sbin PATH=$PATH:/usr/local/bin:$ORACLE_HOME/bin export PATH Installing Oracle Due to a slight inconsistency in the Linux emulator, you need to create a directory named .oracle in /var/tmp before you start the installer. Either make it world writable or let it be owner by the oracle user. You should be able to install Oracle without any problems. If you have problems, check your Oracle distribution and/or configuration first! After you have installed Oracle, apply the patches described in the next two subsections. A frequent problem is that the TCP protocol adapter is not installed right. As a consequence, you cannot start any TCP listeners. The following actions help solve this problem: &prompt.root; cd $ORACLE_HOME/network/lib &prompt.root; make -f ins_network.mk ntcontab.o &prompt.root; cd $ORACLE_HOME/lib &prompt.root; ar r libnetwork.a ntcontab.o &prompt.root; cd $ORACLE_HOME/network/lib &prompt.root; make -f ins_network.mk install Do not forget to run root.sh again! Patching root.sh When installing Oracle, some actions, which need to be performed as root, are recorded in a shell script called root.sh. root.sh is written in the orainst directory. Apply the following patch to root.sh, to have it use to proper location of chown or alternatively run the script under a Linux native shell. *** orainst/root.sh.orig Tue Oct 6 21:57:33 1998 --- orainst/root.sh Mon Dec 28 15:58:53 1998 *************** *** 31,37 **** # This is the default value for CHOWN # It will redefined later in this script for those ports # which have it conditionally defined in ss_install.h ! CHOWN=/bin/chown # # Define variables to be used in this script --- 31,37 ---- # This is the default value for CHOWN # It will redefined later in this script for those ports # which have it conditionally defined in ss_install.h ! CHOWN=/usr/sbin/chown # # Define variables to be used in this script When you do not install Oracle from CD, you can patch the source for root.sh. It is called rthd.sh and is located in the orainst directory in the source tree. Patching genclntsh The script genclntsh is used to create a single shared client library. It is used when building the demos. Apply the following patch to comment out the definition of PATH: *** bin/genclntsh.orig Wed Sep 30 07:37:19 1998 --- bin/genclntsh Tue Dec 22 15:36:49 1998 *************** *** 32,38 **** # # Explicit path to ensure that we're using the correct commands #PATH=/usr/bin:/usr/ccs/bin export PATH ! PATH=/usr/local/bin:/bin:/usr/bin:/usr/X11R6/bin export PATH # # each product MUST provide a $PRODUCT/admin/shrept.lst --- 32,38 ---- # # Explicit path to ensure that we're using the correct commands #PATH=/usr/bin:/usr/ccs/bin export PATH ! #PATH=/usr/local/bin:/bin:/usr/bin:/usr/X11R6/bin export PATH # # each product MUST provide a $PRODUCT/admin/shrept.lst Running Oracle When you have followed the instructions, you should be able to run Oracle as if it was run on Linux itself. Holger Kipp Contributed by Valentino Vaschetto Original version converted to SGML by Installing SAP R/3 applications SAP R/3 Installations of SAP Systems using FreeBSD will not be supported by the SAP support team — they only offer support for certified platforms. Preface This document describes a possible way of installing a SAP R/3-System with Oracle Database for Linux onto a FreeBSD machine, including the installation of FreeBSD and Oracle. Two different configurations will be described: SAP R/3 4.6B (IDES) with Oracle 8.0.5 on FreeBSD 4.3-STABLE SAP R/3 4.6C with Oracle 8.1.7 on FreeBSD 4.5-STABLE Even though this document tries to describe all important steps in a greater detail, it is not intended as a replacement for the Oracle and SAP R/3 installation guides. Please see the documentation that comes with the SAP R/3 Linux edition for SAP- and Oracle-specific questions, as well as resources from Oracle and SAP OSS. Software The following CD-ROMs have been used for SAP-installations: SAP R/3 4.6B, Oracle 8.0.5 Name Number Description KERNEL 51009113 SAP Kernel Oracle / Installation / AIX, Linux, Solaris RDBMS 51007558 Oracle / RDBMS 8.0.5.X / Linux EXPORT1 51010208 IDES / DB-Export / Disc 1 of 6 EXPORT2 51010209 IDES / DB-Export / Disc 2 of 6 EXPORT3 51010210 IDES / DB-Export / Disc 3 of 6 EXPORT4 51010211 IDES / DB-Export / Disc 4 of 6 EXPORT5 51010212 IDES / DB-Export / Disc 5 of 6 EXPORT6 51010213 IDES / DB-Export / Disc 6 of 6 Additionally, I used the Oracle 8 Server (Pre-production version 8.0.5 for Linux, Kernel Version 2.0.33) CD which is not really necessary, and of course FreeBSD 4.3-STABLE (it was only a few days past 4.3 RELEASE). SAP R/3 4.6C SR2, Oracle 8.1.7 Name Number Description KERNEL 51014004 SAP Kernel Oracle / SAP Kernel Version 4.6D / DEC, Linux RDBMS 51012930 Oracle 8.1.7/ RDBMS / Linux EXPORT1 51013953 Release 4.6C SR2 / Export / Disc 1 of 4 EXPORT1 51013953 Release 4.6C SR2 / Export / Disc 2 of 4 EXPORT1 51013953 Release 4.6C SR2 / Export / Disc 3 of 4 EXPORT1 51013953 Release 4.6C SR2 / Export / Disc 4 of 4 LANG1 51013954 Release 4.6C SR2 / Language / DE, EN, FR / Disc 1 of 3 Depending on the languages you would like to install, additional language CDs might be necessary. Here we're just using DE and EN, so the first Language-CD is the only one needed. As a little note, the numbers for all four export CDs are identical. All three language CDs also have the same number (this is different from the 4.6B IDES release CD numbering). At the time of writing this installation is running on FreeBSD 4.5-STABLE (20.03.2002). SAP-Notes The following notes should be read before installing SAP R/3 or proved to be useful during installation: SAP R/3 4.6B, Oracle 8.0.5 Number Title 0171356 SAP Software on Linux: Essential Comments 0201147 INST: 4.6C R/3 Inst. on UNIX - Oracle 0373203 Update / Migration Oracle 8.0.5 --> 8.0.6/8.1.6 LINUX 0072984 Release of Digital UNIX 4.0B for Oracle 0130581 R3SETUP step DIPGNTAB terminates 0144978 Your system has not been installed correctly 0162266 Questions and tips for R3SETUP on Windows NT / W2K SAP R/3 4.6C, Oracle 8.1.7 Number Title 0015023 Initializing table TCPDB (RSXP0004) (EBCDIC) 0045619 R/3 with several languages or typefaces 0171356 SAP Software on Linux: Essential Comments 0195603 RedHat 6.1 Enterprise version: Known problems 0212876 The new archiving tool SAPCAR 0300900 Linux: Released DELL Hardware 0377187 RedHat 6.2: important remarks 0387074 INST: R/3 4.6C SR2 Installation on UNIX 0387077 INST: R/3 4.6C SR2 Inst. on UNIX - Oracle 0387078 SAP Software on UNIX: OS Dependencies 4.6C SR2 Hardware-Requirements The following equipment is sufficient for the installation of a SAP R/3 System. For production use, a more exact sizing is of course needed: Component 4.6B 4.6C Processor 2 x 800MHz Pentium III 2 x 800MHz Pentium III Memory 1GB ECC 2GB ECC Hard Disk Space 50-60GB (IDES) 50-60GB (IDES) For use in production, Xeon-Processors with large cache, high-speed disk access (SCSI, RAID hardware controller), USV and ECC-RAM is recommended. The large amount of hard disk space is due to the preconfigured IDES System, which creates 27 GB of database files during installation. This space is also sufficient for initial production systems and application data. SAP R/3 4.6B, Oracle 8.0.5 The following off-the-shelf hardware was used: a dual processor board with 2 800 MHz Pentium III processors, Adaptec 29160 Ultra160 SCSI adapter (for accessing a 40/80 GB DLT tape drive and CDROM), Mylex AcceleRAID (2 channels, firmware 6.00-1-00 with 32 MB RAM). To the Mylex Raid-controller are attached two 17 GB hard disks (mirrored) and four 36 GB hard disks (RAID level 5). SAP R/3 4.6C, Oracle 8.1.7 For this installation a DELL PowerEdge 2500 was used: a dual processor board with two 1000 MHz Pentium III processors (256 kB Cache), 2 GB PC133 ECC SDRAM, PERC/3 DC PCI Raid Controller with 128 MB, and an EIDE DVD-ROM drive. To the RAID-controller are attached two 18 GB hard disks (mirrored) and four 36 GB hard disks (RAID level 5). Installation of FreeBSD First you have to install FreeBSD. There are several ways to do this (FreeBSD 4.3 was installed via FTP, FreeBSD 4.5 directly from release-CD). Disk Layout To keep it simple, the same disk layout both for the SAP R/3 46B- and SAP R/3 46C SR2-installation was used. Only the device names changed, as the installations were on different hardware (/dev/da and /dev/amr respectively, so if using an AMI MegaRAID, one will see /dev/amr0s1a instead of /dev/da0s1a): File system Size (1k-blocks) Size (GB) Mounted on /dev/da0s1a 1.016.303 1 / /dev/da0s1b 6 swap /dev/da0s1e 2.032.623 2 /var /dev/da0s1f 8.205.339 8 /usr /dev/da1s1e 45.734.361 45 /compat/linux/oracle /dev/da1s1f 2.032.623 2 /compat/linux/sapmnt /dev/da1s1g 2.032.623 2 /compat/linux/usr/sap Configure and initialize the two logical drives with the Mylex- or PERC/3 RAID software beforehand. The software can be started during the bios boot phase. Please note that this disk layout differs slightly from the SAP recommendations, as SAP suggests mounting the oracle-subdirectories (and some others) separately - I decided to just create them as real subdirectories for simplicity. <command>make world</command> and a New Kernel Download the latest stable-sources. Rebuild world and your custom kernel after configuring your kernel configuration file. Here you should also include the kernel parameters which are required for both SAP R/3 and Oracle. Installing the Linux Environment During the first installation with FreeBSD 4.3-STABLE I had some trouble downloading the required RPM-files (for 4.3 stable, 2nd May 2001), but with FreeBSD 4.5-STABLE, everything went very smooth. Should you encounter some problems, try to download those files by hand. For a list of RPM-Mirrors and required files, see the corresponding makefile. Installing Linux Base-system First the linux_base port needs to be installed (as root). This is currently linux_base-6. &prompt.root; cd /usr/ports/emulators/linux_base &prompt.root; make package Installing Linux Development The Linux development is needed, if you want to install Oracle on FreeBSD according to the corresponding description in the handbook: &prompt.root; cd /usr/ports/devel/linux_devtools &prompt.root; make package Linux Development has only been installed for the SAP R/3 46B IDES-installation. It is not needed, if the Oracle DB is not relinked on the FreeBSD system. This is the case if you are using the - Oracle tarball from a linux system. + Oracle tarball from a Linux system. Installing Necessary RPMs RPMs To start the R3SETUP-Program, PAM support is needed. During the first SAP-Installation on FreeBSD 4.3-STABLE I tried to install PAM with all the required packages and finally forced the installation of the PAM package, which worked. For SAP R/3 4.6C SR2 I directly forced the installation of the PAM-RPM, which also works, so it seems the dependent packages are not needed: &prompt.root; rpm -i --ignoreos --nodeps --root /compat/linux --dbpath /var/lib/rpm \ pam-0.68-7.i386.rpm For Oracle 8.0.5 to run the intelligent agent, I also had to install the RedHat Tcl package tcl-8.0.5-30.i386.rpm (otherwise the relinking during Oracle install will not work). There are some other issues regarding relinking of Oracle, but that is a Oracle-Linux issue, not FreeBSD specific. Some additional hints It might also be a good idea to add linprocfs to /etc/fstab. See man linprocfs. Another parameter to set is kern.fallback_elf_brand=3 which is done in file /etc/sysctl.conf. Creating the SAP/R3 Environment Creating the Necessary File Systems and Mountpoints For a simple installation, it is sufficient to create the following file systems: mount point size in GB /compat/linux/oracle 45 GB /compat/linux/sapmnt 2 GB /compat/linux/usr/sap 2 GB It is also necessary to created some links. Otherwise the SAP-Installer will complain, as it is checking the created links: &prompt.root; ln -s /compat/linux/oracle /oracle &prompt.root; ln -s /compat/linux/sapmnt /sapmnt &prompt.root; ln -s /compat/linux/usr/sap /usr/sap Possible error message during installation (here with System PRD and the SAP R/3 4.6C SR2 installation): INFO 2002-03-19 16:45:36 R3LINKS_IND_IND SyLinkCreate:200 Checking existence of symbolic link /usr/sap/PRD/SYS/exe/dbg to /sapmnt/PRD/exe. Creating if it does not exist... WARNING 2002-03-19 16:45:36 R3LINKS_IND_IND SyLinkCreate:400 Link /usr/sap/PRD/SYS/exe/dbg exists but it points to file /compat/linux/sapmnt/PRD/exe instead of /sapmnt/PRD/exe. The program cannot go on as long as this link exists at this location. Move the link to another location. ERROR 2002-03-19 16:45:36 R3LINKS_IND_IND Ins_SetupLinks:0 can not setup link '/usr/sap/PRD/SYS/exe/dbg' with content '/sapmnt/PRD/exe' Creating Users and Directories SAP R/3 needs two users and three groups. The user names depend on the SAP system id (SID) which consists of three letters. Some of these SIDs are reserved by SAP (for example SAP and NIX. For a complete list please see the SAP documentation). For the IDES installation I used IDS, for the 4.6C SR2 installation PRD, as that system is intended for production use. We have therefore the following groups (group ids might differ, these are just the values I used with my installation): group id group name description 100 dba Data Base Administrator 101 sapsys SAP System 102 oper Data Base Operator For a default Oracle-Installation, only group dba is used. As oper-group, one also uses group dba (see Oracle- and SAP-documentation for further information). We also need the following users: user id user name generic name group additional groups description 1000 idsadm/prdadm sidadm sapsys oper SAP Administrator 1002 oraids/oraprd orasid dba oper DB Administrator Adding the users with adduser requires the following (please note shell and home directory) entries for SAP-Administrator: Name: sidadm Password: ****** Fullname: SAP Administrator SID Uid: 1000 Gid: 101 (sapsys) Class: Groups: sapsys dba HOME: /home/sidadm Shell: bash (/compat/linux/bin/bash) and for Database-Administrator: Name: orasid Password: ****** Fullname: Oracle Administrator SID Uid: 1002 Gid: 100 (dba) Class: Groups: dba HOME: /oracle/sid Shell: bash (/compat/linux/bin/bash) This should also include group oper in case you are using both groups dba and oper. Creating Directories These directories are usually created as separate file systems. This depends entirely on your requirements. I choose to create them as simple directories, as they are all located on the same RAID 5 anyway: First we will set owners and rights of some directories (as user root): &prompt.root; chmod 775 /oracle &prompt.root; chmod 777 /sapmnt &prompt.root; chown root:dba /oracle &prompt.root; chown sidadm:sapsys /compat/linux/usr/sap &prompt.root; chmod 775 /compat/linux/usr/sap Second we will create directories as user orasid. These will all be subdirectories of /oracle/SID: &prompt.root; su - orasid &prompt.root; cd /oracle/SID &prompt.root; mkdir mirrlogA mirrlogB origlogA origlogB &prompt.root; mkdir sapdata1 sapdata2 sapdata3 sapdata4 sapdata5 sapdata6 &prompt.root; mkdir saparch sapreorg &prompt.root; exit For the Oracle 8.1.7-installation some additional directories are needed: &prompt.root; su - orasid &prompt.root; cd /oracle &prompt.root; mkdir 805_32 &prompt.root; mkdir client stage &prompt.root; mkdir client/80x_32 &prompt.root; mkdir stage/817_32 &prompt.root; cd /oracle/SID &prompt.root; mkdir 817_32 The directory client/80x_32 is used with exactly this name. Don't replace the x with some number or anything. In the third step we create directories as user sidadm: &prompt.root; su - sidadm &prompt.root; cd /usr/sap &prompt.root; mkdir SID &prompt.root; mkdir trans &prompt.root; exit Entries in /etc/services SAP R/3 requires some entries in file /etc/services, which will not be set correctly during installation under FreeBSD. Please add the following entries (you need at least those entries corresponding to the instance number - in this case, 00. It will do no harm adding all entries from 00 to 99 for dp, gw, sp and ms). If you are going to use a saprouter or need to access SAP OSS, you also need 99, as port 3299 is usually used for the saprouter process on the target system: sapdp00 3200/tcp # SAP Dispatcher. 3200 + Instance-Number sapgw00 3300/tcp # SAP Gateway. 3300 + Instance-Number sapsp00 3400/tcp # 3400 + Instance-Number sapms00 3500/tcp # 3500 + Instance-Number sapmsSID 3600/tcp # SAP Message Server. 3600 + Instance-Number sapgw00s 4800/tcp # SAP Secure Gateway 4800 + Instance-Number Necessary Locales locale SAP requires at least two locales that are not part of the default RedHat installation. SAP offers the required RPMs as download from their FTP-server (which is only accessible if you are a customer with OSS-access). See note 0171356 for a list of RPMs you need. It is also possible to just create appropriate links (for example from de_DE and en_US ), but I would not recommend this for a production system (so far it worked with the IDES system without any problems, though). The following locales are needed: de_DE.ISO-8859-1 en_US.ISO-8859-1 Create the links like this: &prompt.root; cd /compat/linux/usr/share/locale &prompt.root; ln -s de_DE de_DE.ISO-8859-1 &prompt.root; ln -s en_US en_US.ISO-8859-1 If they are not present, there will be some problems during the installation. If these are then subsequently ignored (by setting the status of the offending steps to OK in file CENTRDB.R3S), it will be impossible to log onto the SAP-system without some additional effort. Kernel Tuning kernel tuning SAP R/3 Systems need a lot of resources. I therefore added the following parameters to my kernel config-file: # Set these for memory pigs (SAP and Oracle): options MAXDSIZ="(1024*1024*1024)" options DFLDSIZ="(1024*1024*1024)" # System V options needed. options SYSVSHM #SYSV-style shared memory options SHMMAXPGS=262144 #max amount of shared mem. pages #options SHMMAXPGS=393216 #use this for the 46C inst.parameters options SHMMNI=256 #max number of shared memory ident if. options SHMSEG=100 #max shared mem.segs per process options SYSVMSG #SYSV-style message queues options MSGSEG=32767 #max num. of mes.segments in system options MSGSSZ=32 #size of msg-seg. MUST be power of 2 options MSGMNB=65535 #max char. per message queue options MSGTQL=2046 #max amount of msgs in system options SYSVSEM #SYSV-style semaphores options SEMMNU=256 #number of semaphore UNDO structures options SEMMNS=1024 #number of semaphores in system options SEMMNI=520 #number of semaphore identifiers options SEMUME=100 #number of UNDO keys The minimum values are specified in the documentation that comes from SAP. As there is no description for Linux, see the HP-UX-section (32-bit) for further information. As the system for the 4.6C SR2 installation has more main memory, the shared segments can be larger both for SAP and Oracle, therefore choose a larger number of shared memory pages. With the default installation of FreeBSD 4.5 on x386, leave MAXDSIZ and DFLDSIZ at 1 GB maximum. Otherwise, strange errors like ORA-27102: out of memory and Linux Error: 12: Cannot allocate memory might happen. Installing SAP R/3 Preparing SAP CDROMs There are many CDROMs to mount and unmount during the installation. Assuming you have enough CDROM-drives, you can just mount them all. I decided to copy the CDROM contents to corresponding directories: /oracle/SID/sapreorg/cd-name where cd-name was one of KERNEL, RDBMS, EXPORT1, EXPORT2, EXPORT3, EXPORT4, EXPORT5 and EXPORT6 for the 4.6B/IDES-installation, and KERNEL, RDBMS, DISK1, DISK2, DISK3, DISK4 and LANG for the 4.6C SR2-installation. All the filenames on the mounted CDs should be in capital letters, otherwise use the option for mounting. So use the following commands: &prompt.root; mount_cd9660 -g /dev/cd0a /mnt &prompt.root; cp -R /mnt/* /oracle/SID/sapreorg/cd-name &prompt.root; umount /mnt Running the install-script First you have to prepare an install-directory: &prompt.root; cd /oracle/SID/sapreorg &prompt.root; mkdir install &prompt.root; cd install Then the install-script is started, which will copy nearly all the relevant files into the install-directory: &prompt.root; /oracle/SID/sapreorg/KERNEL/UNIX/INSTTOOL.SH The IDES-Installation (4.6B) comes with a fully customized SAP R/3 Demo-System, so there are six instead of just three EXPORT-CDs. At this point the installation template CENTRDB.R3S is for installing a standard central instance (R/3 and Database), not the IDES central instance, so one needs to copy the corresponding CENTRDB.R3S from the EXPORT1 directory, otherwise R3SETUP will only ask for three EXPORT-CDs. The newer SAP 4.6C SR2-release comes with four EXPORT-CDs. The parameter-file that controls the installation-steps is CENTRAL.R3S. Contrary to earlier releases there are no separate installation templates for a central instance with or without database. SAP is using a separate template for DB-installation. To restart the installation later it is however sufficient to restart with the original file. During and after installation, SAP requires hostname to return the computer name only, not the fully qualified domain name. So either set the hostname accordingly, or set an alias with alias hostname='hostname -s' for both orasid and sidadm (and for root at least during installation steps performed as root). It is also possible to adjust the installed profile- and login-scripts of both users that are installed during SAP-installation. Start R3SETUP 4.6B Make sure LD_LIBRARY_PATH is set correctly: &prompt.root; export LD_LIBRARY_PATH=/oracle/IDS/lib:/sapmnt/IDS/exe:/oracle/805_32/lib Start R3SETUP as root from installation directory: &prompt.root; cd /oracle/IDS/sapreorg/install &prompt.root; ./R3SETUP -f CENTRDB.R3S The script then asks some questions (defaults in brackets, followed by actual input): Question Default Input Enter SAP System ID [C11] IDSEnter Enter SAP Instance Number [00] Enter Enter SAPMOUNT Directory [/sapmnt] Enter Enter name of SAP central host [troubadix.domain.de] Enter Enter name of SAP db host [troubadix] Enter Select character set [1] (WE8DEC) Enter Enter Oracle server version (1) Oracle 8.0.5, (2) Oracle 8.0.6, (3) Oracle 8.1.5, (4) Oracle 8.1.6 1Enter Extract Oracle Client archive [1] (Yes, extract) Enter Enter path to KERNEL CD [/sapcd] /oracle/IDS/sapreorg/KERNEL Enter path to RDBMS CD [/sapcd] /oracle/IDS/sapreorg/RDBMS Enter path to EXPORT1 CD [/sapcd] /oracle/IDS/sapreorg/EXPORT1 Directory to copy EXPORT1 CD [/oracle/IDS/sapreorg/CD4_DIR] Enter Enter path to EXPORT2 CD [/sapcd] /oracle/IDS/sapreorg/EXPORT2 Directory to copy EXPORT2 CD [/oracle/IDS/sapreorg/CD5_DIR] Enter Enter path to EXPORT3 CD [/sapcd] /oracle/IDS/sapreorg/EXPORT3 Directory to copy EXPORT3 CD [/oracle/IDS/sapreorg/CD6_DIR] Enter Enter path to EXPORT4 CD [/sapcd] /oracle/IDS/sapreorg/EXPORT4 Directory to copy EXPORT4 CD [/oracle/IDS/sapreorg/CD7_DIR] Enter Enter path to EXPORT5 CD [/sapcd] /oracle/IDS/sapreorg/EXPORT5 Directory to copy EXPORT5 CD [/oracle/IDS/sapreorg/CD8_DIR] Enter Enter path to EXPORT6 CD [/sapcd] /oracle/IDS/sapreorg/EXPORT6 Directory to copy EXPORT6 CD [/oracle/IDS/sapreorg/CD9_DIR] Enter Enter amount of RAM for SAP + DB 850Enter (in Megabytes) Service Entry Message Server [3600] Enter Enter Group-ID of sapsys [101] Enter Enter Group-ID of oper [102] Enter Enter Group-ID of dba [100] Enter Enter User-ID of sidadm [1000] Enter Enter User-ID of orasid [1002] Enter Number of parallel procs [2] Enter If you had not copied the CDs to the different locations, then the SAP-Installer cannot find the CD needed (identified by the LABEL.ASC-File on CD) and would then ask you to insert and mount the CD and confirm or enter the mount path. The CENTRDB.R3S might not be error-free. In my case, it requested EXPORT4 again (but indicated the correct key (6_LOCATION, then 7_LOCATION etc.), so one can just continue with entering the correct values. Do not get irritated. Apart from some problems mentioned below, everything should go straight through up to the point where the Oracle database software needs to be installed. Start R3SETUP 4.6C SR2 Make sure LD_LIBRARY_PATH is set correctly. This is a different value from the 4.6B installation with Oracle 8.0.5: &prompt.root; export LD_LIBRARY_PATH=/sapmnt/PRD/exe:/oracle/PRD/817_32/lib Start R3SETUP as user root from installation directory: &prompt.root; cd /oracle/PRD/sapreorg/install &prompt.root; ./R3SETUP -f CENTRAL.R3S The script then asks some questions (defaults in brackets, followed by actual input): Question Default Input Enter SAP System ID [C11] PRDEnter Enter SAP Instance Number [00] Enter Enter SAPMOUNT Directory [/sapmnt] Enter Enter name of SAP central host [majestix] Enter Enter Database System ID [PRD] PRDEnter Enter name of SAP db host [majestix] Enter Select character set [1] (WE8DEC) Enter Enter Oracle server version (2) Oracle 8.1.7 2Enter Extract Oracle Client archive [1] (Yes, extract) Enter Enter path to KERNEL CD [/sapcd] /oracle/PRD/sapreorg/KERNEL Enter amount of RAM for SAP + DB 2044 1800Enter (in Megabytes) Service Entry Message Server [3600] Enter Enter Group-ID of sapsys [100] Enter Enter Group-ID of oper [101] Enter Enter Group-ID of dba [102] Enter Enter User-ID of oraprd [1002] Enter Enter User-ID of prdadm [1000] Enter LDAP support 3Enter (no support) Installation step completed [1] (continue) Enter Choose installation service [1] (DB inst,file) Enter So far, creation of users gives an error during installation in phases OSUSERDBSID_IND_ORA (for creating user orasid) and OSUSERSIDADM_IND_ORA (creating user sidadm). Apart from some problems mentioned below, everything should go straight through up to the point where the Oracle database software needs to be installed. Installing Oracle 8.0.5 Please see the corresponding SAP-Notes and Oracle Readmes regarding Linux and Oracle DB for possible problems. Most if not all problems stem from incompatible libraries. For more information on installing Oracle, refer to the Installing Oracle chapter. Installing the Oracle 8.0.5 with orainst If Oracle 8.0.5 is to be used, some additional libraries are needed for successfully relinking, as Oracle 8.0.5 was linked with an old glibc (RedHat 6.0), but RedHat 6.1 already uses a new glibc. So you have to install the following additional packages to ensure that linking will work: compat-libs-5.2-2.i386.rpm compat-glibc-5.2-2.0.7.2.i386.rpm compat-egcs-5.2-1.0.3a.1.i386.rpm compat-egcs-c++-5.2-1.0.3a.1.i386.rpm compat-binutils-5.2-2.9.1.0.23.1.i386.rpm See the corresponding SAP-Notes or Oracle Readmes for further information. If this is no option (at the time of installation I did not have enough time to check this), one could use the original binaries, or use the relinked binaries from an original RedHat System. For compiling the intelligent agent, the RedHat Tcl package must be installed. If you cannot get tcl-8.0.3-20.i386.rpm, a newer one like tcl-8.0.5-30.i386.rpm for RedHat 6.1 should also do. Apart from relinking, the installation is straightforward: &prompt.root; su - oraids &prompt.root; export TERM=xterm &prompt.root; export ORACLE_TERM=xterm &prompt.root; export ORACLE_HOME=/oracle/IDS &prompt.root; cd /ORACLE_HOME/orainst_sap &prompt.root; ./orainst Confirm all Screens with Enter until the software is installed, except that one has to deselect the Oracle On-Line Text Viewer, as this is not currently available for Linux. Oracle then wants to relink with i386-glibc20-linux-gcc instead of the available gcc, egcs or i386-redhat-linux-gcc . Due to time constrains I decided to use the binaries from an Oracle 8.0.5 PreProduction release, after the first attempt at getting the version from the RDBMS-CD working, failed, and finding and accessing the correct RPMs was a nightmare at that time. Installing the Oracle 8.0.5 Pre-Production release for Linux (Kernel 2.0.33) This installation is quite easy. Mount the CD, start the installer. It will then ask for the location of the Oracle home directory, and copy all binaries there. I did not delete the remains of my previous RDBMS-installation tries, though. Afterwards, Oracle Database could be started with no problems. Installing the Oracle 8.1.7 linux tarball Take the tarball oracle81732.tgz you - produced from the installation directory on a linux system + produced from the installation directory on a Linux system and untar it to /oracle/SID/817_32/. Continue with SAP R/3 Installation First check the environment settings of users idsamd (sidadm) and oraids (orasid). They should now both have the files .profile, .login and .cshrc which are all using hostname. In case the system's hostname is the fully qualified name, you need to change hostname to hostname -s within all three files. Database Load Afterwards, R3SETUP can either be restarted or continued (depending on whether exit was chosen or not). R3SETUP then creates the tablespaces and loads the data (for 46B IDES, from EXPORT1 to EXPORT6, for 46C from DISK1 to DISK4) with R3load into the database. When the database load is finished (might take a few hours), some passwords are requested. For test installations, one can use the well known default passwords (use different ones if security is an issue!): Question Input Enter Password for sapr3 sapEnter Confirum Password for sapr3 sapEnter Enter Password for sys change_on_installEnter Confirm Password for sys change_on_installEnter Enter Password for system managerEnter Confirm Password for system managerEnter At this point I had a few problems with dipgntab during the 4.6B installation. Listener Start the Oracle-Listener as user orasid as follows: &prompt.user; umask 0; lsnrctl start Otherwise you might get ORA-12546 as the sockets will not have the correct permissions. See SAP note 072984. Updating MNLS Tables If you plan to import non-Latin-1 languages into the SAP-System, you have to update the Multi National Language Support tables. This is described in the SAP OSS-Notes 15023 and 45619. Otherwise, you can skip this question during SAP installation. If you don't need MNLS, it is still necessary to check table TCPDB and initializing it if this hasn't been done. See SAP note 0015023 and 0045619 for further information. Post-installation Steps Request SAP R/3 License Key You have to request your SAP R/3 License Key. This is needed, as the temporary license that was installed during installation is only valid for four weeks. First get the hardware key. Log on as user idsadm and call saplicense: &prompt.root; /sapmnt/IDS/exe/saplicense -get Calling saplicense without options gives a list of options. Upon receiving the license key, it can be installed using: &prompt.root; /sapmnt/IDS/exe/saplicense -install You are then required to enter the following values: SAP SYSTEM ID = SID, 3 chars CUSTOMER KEY = hardware key, 11 chars INSTALLATION NO = installation, 10 digits EXPIRATION DATE = yyyymmdd, usually "99991231" LICENSE KEY = license key, 24 chars Creating Users Create a user within client 000 (for some tasks required to be done within client 000, but with a user different from users sap* and ddic). As a user name, I usually choose wartung (or service in English). Profiles required are sap_new and sap_all. For additional safety the passwords of default users within all clients should be changed (this includes users sap* and ddic). Configure Transport System, Profile, Operation Modes, Etc. Within client 000, user different from ddic and sap*, do at least the following: Task Transaction Configure Transport System, eg as Stand-Alone Transport Domain Entity STMS Create / Edit Profile for System RZ10 Maintain Operation Modes and Instances RZ04 These and all the other post-installation steps are thoroughly described in SAP installation guides. Edit init<replaceable>sid</replaceable>.sap (initIDS.sap) The file /oracle/IDS/dbs/initIDS.sap contains the SAP backup profile. Here the size of the tape to be used, type of compression and so on need to be defined. To get this running with sapdba / brbackup, I changed the following values: compress = hardware archive_function = copy_delete_save cpio_flags = "-ov --format=newc --block-size=128 --quiet" cpio_in_flags = "-iuv --block-size=128 --quiet" tape_size = 38000M tape_address = /dev/nsa0 tape_address_rew = /dev/sa0 Explanations: compress The tape I use is a HP DLT1 which does hardware compression. archive_function This defines the default behavior for saving Oracle archive logs: New logfiles are saved to tape, already saved logfiles are saved again and are then deleted. This prevents lots of trouble if you need to recover the database, and one of the archive-tapes has gone bad. cpio_flags Default is to use -B which sets block size to 5120 Bytes. For DLT-Tapes, HP recommends at least 32 K block size, so I used --block-size=128 for 64 K. --format=newc is needed I have inode numbers greater than 65535. The last option --quiet is needed as otherwise brbackup complains as soon as cpio outputs the numbers of blocks saved. cpio_in_flags Flags needed for loading data back from tape. Format is recognized automatically. tape_size This usually gives the raw storage capability of the tape. For security reason (we use hardware compression), the value is slightly lower than the actual value. tape_address The non-rewindable device to be used with cpio. tape_address_rew The rewindable device to be used with cpio. Configuration Issues after Installation The following SAP-parameters should be tuned after installation (examples for IDES 46B, 1 GB memory): Name Value ztta/roll_extension 250000000 abap/heap_area_dia 300000000 abap/heap_area_nondia 400000000 em/initial_size_MB 256 em/blocksize_kB 1024 ipc/shm_psize_40 70000000 SAP-Note 0013026: Name Value ztta/dynpro_area 2500000 SAP-Note 0157246: Name Value rdisp/ROLL_MAXFS 16000 rdisp/PG_MAXFS 30000 With the above parameters, on a system with 1 gigabyte of memory, one may find memory consumption similar to: Mem: 547M Active, 305M Inact, 109M Wired, 40M Cache, 112M Buf, 3492K Free Problems During Installation Restart R3SETUP after fixing a problem R3SETUP stops if it encounters an error. If you have looked at the corresponding logfiles and fixed the error, you have to start R3SETUP again, usually selecting REPEAT as option for the last step R3SETUP complained about. To restart R3SETUP, just start it with the corresponding R3S-file: &prompt.root; ./R3SETUP -f CENTRDB.R3S for 4.6B, or with &prompt.root; ./R3SETUP -f CENTRAL.R3S for 4.6C, no matter whether the error occurred with CENTRAL.R3S or DATABASE.R3S. At some stages, R3SETUP assumes that both database- and SAP-processes are up and running (as those were steps it already completed). Should errors occur and for example the database could not be started, you have to start both database and SAP by hand after you fixed the errors and before starting R3SETUP again. Don't forget to also start the oracle listener again (as orasid with umask 0; lsnrctl start) if it was also stopped (for example due to a necessary reboot of the system). OSUSERSIDADM_IND_ORA During R3SETUP If R3SETUP complains at this stage, edit the template file R3SETUP used at that time (CENTRDB.R3S (4.6B) or either CENTRAL.R3S or DATABASE.R3S (4.6C)). Locate [OSUSERSIDADM_IND_ORA] or search for the only STATUS=ERROR-entry and edit the following values: HOME=/home/sidadm (was empty) STATUS=OK (had status ERROR) Then you can restart R3SETUP again. OSUSERDBSID_IND_ORA During R3SETUP Possibly R3SETUP also complains at this stage. The error here is similar to the one in phase OSUSERSIDADM_IND_ORA. Just edit the template file R3SETUP used at that time (CENTRDB.R3S (4.6B) or either CENTRAL.R3S or DATABASE.R3S (4.6C)). Locate [OSUSERDBSID_IND_ORA] or search for the only STATUS=ERROR-entry and edit the following value in that section: STATUS=OK Then restart R3SETUP. <errorname>oraview.vrf FILE NOT FOUND</errorname> During Oracle Installation You have not deselected Oracle On-Line Text Viewer before starting the installation. This is marked for installation even though this option is currently not available for Linux. Deselect this product inside the Oracle installation menu and restart installation. <errorname>TEXTENV_INVALID</errorname> During R3SETUP, RFC or SAPGUI Start If this error is encountered, the correct locale is missing. SAP note 0171356 lists the necessary RPMs that need be installed (eg saplocales-1.0-3, saposcheck-1.0-1 for RedHat 6.1). In case you ignored all the related errors and set the corresponding status from ERROR to OK (in CENTRDB.R3S) every time R3SETUP complained and just restarted R3SETUP, the SAP-System will not be properly configured and you will then not be able to connect to the system with a sapgui, even though the system can be started. Trying to connect with the old Linux sapgui gave the following messages: Sat May 5 14:23:14 2001 *** ERROR => no valid userarea given [trgmsgo. 0401] Sat May 5 14:23:22 2001 *** ERROR => ERROR NR 24 occured [trgmsgi. 0410] *** ERROR => Error when generating text environment. [trgmsgi. 0435] *** ERROR => function failed [trgmsgi. 0447] *** ERROR => no socket operation allowed [trxio.c 3363] Speicherzugriffsfehler This behavior is due to SAP R/3 being unable to correctly assign a locale and also not being properly configured itself (missing entries in some database tables). To be able to connect to SAP, add the following entries to file DEFAULT.PFL (see note 0043288): abap/set_etct_env_at_new_mode = 0 install/collate/active = 0 rscp/TCP0B = TCP0B Restart the SAP system. Now you can connect to the system, even though country-specific language settings might not work as expected. After correcting country-settings (and providing the correct locales), these entries can be removed from DEFAULT.PFL and the SAP system can be restarted. <errorcode>ORA-00001</errorcode> This error only happened with Oracle 8.1.7 on FreeBSD 4.5. The reason was that the Oracle database could not initialize itself properly and crashed, leaving semaphores and shared memory on the system. The next try to start the database then returned ORA-00001. Find them with ipcs -a and remove them with ipcrm. <errorcode>ORA-00445</errorcode> (background process PMON did not start) This error happened with Oracle 8.1.7. This error is reported if the Database is started with the usual startsap-script (for example startsap_majestix_00) as user prdadm. A possible workaround is to start the database as user oraprd instead with svrmgrl: &prompt.user; svrmgrl SVRMGR> connect internal; SVRMGR> startup; SVRMGR> exit <errorcode>ORA-12546</errorcode> (start Listener with Correct Permissions) Start the Oracle Listener as user oraids with the following commands: &prompt.root; umask 0; lsnrctl start Otherwise you might get ORA-12546 as the sockets will not have the correct permissions. See SAP note 0072984. <errorcode>ORA-27102</errorcode> (out of memory) This error happened whilst trying to use values for MAXDSIZ and DFLDSIZ greater than 1 GB (1024x1024x1024). Additionally, I got Linux Error 12: Cannot allocate memory. [DIPGNTAB_IND_IND] During R3SETUP In general, see SAP note 0130581 (R3SETUP step DIPGNTAB terminates). During the IDES-specific installation, for some reasons the installation process was not using the proper SAP system name IDS, but the empty string "" instead. This lead to some minor problems with accessing directories, as the paths are generated dynamically using SID (in this case IDS). So instead of accessing: /usr/sap/IDS/SYS/... /usr/sap/IDS/DVMGS00 the following paths were used: /usr/sap//SYS/... /usr/sap/D00 To continue with the installation, I created a link and an additional directory: &prompt.root; pwd /compat/linux/usr/sap &prompt.root; ls -l total 4 drwxr-xr-x 3 idsadm sapsys 512 May 5 11:20 D00 drwxr-x--x 5 idsadm sapsys 512 May 5 11:35 IDS lrwxr-xr-x 1 root sapsys 7 May 5 11:35 SYS -> IDS/SYS drwxrwxr-x 2 idsadm sapsys 512 May 5 13:00 tmp drwxrwxr-x 11 idsadm sapsys 512 May 4 14:20 trans I also found SAP notes (0029227 and 0008401) describing this behavior. I did not encounter any of these problems with the SAP 4.6C-installation. [RFCRSWBOINI_IND_IND] During R3SETUP During installation of SAP 4.6C, this error was just the result of another error happening earlier during installation. In this case, you have to look through the corresponding logfiles and correct the real problem. If after looking through the logfiles this error is indeed the correct one (check the SAP-notes), you can set STATUS of the offending step from ERROR to OK (file CENTRDB.R3S) and restart R3SETUP. After installation, you have to execute the report RSWBOINS from transaction SE38. See SAP note 0162266 for additional information about phase RFCRSWBOINI and RFCRADDBDIF. [RFCRADDBDIF_IND_IND] During R3SETUP Here the same restrictions apply: Make sure by looking through the logfiles, that this error is not caused by some previous problems. If you can confirm that SAP-Note 0162266 applies, just set STATUS of the offending step from ERROR to OK (file CENTRDB.R3S) and restart R3SETUP. After installation, you have to execute the report RADDBDIF from transaction SE38. sigaction sig31: File size limit exceeded - This error occured during start of SAP-processes + This error occurred during start of SAP-processes disp+work. If starting SAP with the startsap-script, subprocesses are then started which detach and do the dirty work of starting all other SAP processes. As a result, the script itself won't notice if something goes wrong. To check whether the SAP processes did start properly, have a look at the process status with ps ax | grep SID, which will give you a list of all Oracle- and SAP-processes. If it looks like some processes are missing or if you can't connect to the SAP-System, look at the corresponding logfiles which can be found at /usr/sap/SID/DVEBMGSnr/work/. The files to look at are dev_ms and dev_disp. Signal 31 happens here if the amount of shared memory used by Oracle and SAP exceed the one defined within the kernel configuration file and could be resolved by using a larger value: # larger value for 46C production systems: options SHMMAXPGS=393216 # smaller value sufficient for 46B: #options SHMMAXPGS=262144 Start of saposcol failed There are some problems with Program saposcol (version 4.6D). The SAP-System is using saposcol to collect data about the system performance. This program is not needed to use the SAP-System, so this problem can be considered a minor one. The older versions (4.6B) does work, but doesn't collect all the data (many calls will just return 0, for example for CPU usage). Advanced Topics If you are curious as to how the Linux binary compatibility works, this is the section you want to read. Most of what follows is based heavily on an email written to &a.chat; by Terry Lambert tlambert@primenet.com (Message ID: <199906020108.SAA07001@usr09.primenet.com>). How Does It Work? execution class loader FreeBSD has an abstraction called an execution class loader. This is a wedge into the &man.execve.2; system call. What happens is that FreeBSD has a list of loaders, instead of a single loader with a fallback to the #! loader for running any shell interpreters or shell scripts. Historically, the only loader on the Unix platform examined the magic number (generally the first 4 or 8 bytes of the file) to see if it was a binary known to the system, and if so, invoked the binary loader. If it was not the binary type for the system, the &man.execve.2; call returned a failure, and the shell attempted to start executing it as shell commands. The assumption was a default of whatever the current shell is. Later, a hack was made for &man.sh.1; to examine the first two characters, and if they were :\n, then it invoked the &man.csh.1; shell instead (we believe SCO first made this hack). What FreeBSD does now is go through a list of loaders, with a generic #! loader that knows about interpreters as the characters which follow to the next whitespace next to last, followed by a fallback to /bin/sh. ELF For the Linux ABI support, FreeBSD sees the magic number as an ELF binary (it makes no distinction between FreeBSD, Solaris, Linux, or any other OS which has an ELF image type, at this point). Solaris The ELF loader looks for a specialized brand, which is a comment section in the ELF image, and which is not present on SVR4/Solaris ELF binaries. For Linux binaries to function, they must be branded as type Linux; from &man.brandelf.1;: &prompt.root; brandelf -t Linux file When this is done, the ELF loader will see the Linux brand on the file. ELF branding When the ELF loader sees the Linux brand, the loader replaces a pointer in the proc structure. All system calls are indexed through this pointer (in a traditional Unix system, this would be the sysent[] structure array, containing the system calls). In addition, the process is flagged for special handling of the trap vector for the signal trampoline code, and several other (minor) fix-ups that are handled by the Linux kernel module. The Linux system call vector contains, among other things, a list of sysent[] entries whose addresses reside in the kernel module. When a system call is called by the Linux binary, the trap code dereferences the system call function pointer off the proc structure, and gets the Linux, not the FreeBSD, system call entry points. In addition, the Linux mode dynamically reroots lookups; this is, in effect, what the union option to FS mounts (not the unionfs!) does. First, an attempt is made to lookup the file in the /compat/linux/original-path directory, then only if that fails, the lookup is done in the /original-path directory. This makes sure that binaries that require other binaries can run (e.g., the Linux toolchain can all run under Linux ABI support). It also means that the Linux binaries can load and exec FreeBSD binaries, if there are no corresponding Linux binaries present, and that you could place a &man.uname.1; command in the /compat/linux directory tree to ensure that the Linux binaries could not tell they were not running on Linux. In effect, there is a Linux kernel in the FreeBSD kernel; the various underlying functions that implement all of the services provided by the kernel are identical to both the FreeBSD system call table entries, and the Linux system call table entries: file system operations, virtual memory operations, signal delivery, System V IPC, etc… The only difference is that FreeBSD binaries get the FreeBSD glue functions, and Linux binaries get the Linux glue functions (most older OS's only had their own glue functions: addresses of functions in a static global sysent[] structure array, instead of addresses of functions dereferenced off a dynamically initialized pointer in the proc structure of the process making the call). Which one is the native FreeBSD ABI? It does not matter. Basically the only difference is that (currently; this could easily be changed in a future release, and probably will be after this) the FreeBSD glue functions are statically linked into the kernel, and the Linux glue functions can be statically linked, or they can be accessed via a kernel module. Yeah, but is this really emulation? No. It is an ABI implementation, not an emulation. There is no emulator (or simulator, to cut off the next question) involved. So why is it sometimes called Linux emulation? To make it hard to sell FreeBSD! Really, it is because the historical implementation was done at a time when there was really no word other than that to describe what was going on; saying that FreeBSD ran Linux binaries was not true, if you did not compile the code in or load a module, and there needed to be a word to describe what was being loaded—hence the Linux emulator.
diff --git a/en_US.ISO8859-1/books/handbook/multimedia/chapter.sgml b/en_US.ISO8859-1/books/handbook/multimedia/chapter.sgml index 388e17940c..350ccf6b72 100644 --- a/en_US.ISO8859-1/books/handbook/multimedia/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/multimedia/chapter.sgml @@ -1,1416 +1,1416 @@ Ross Lippert Edited by Multimedia Synopsis FreeBSD supports a wide variety of sound cards, allowing you to enjoy high fidelity output from your computer. This includes the ability to record and playback audio in the MPEG Audio Layer 3 (MP3), WAV, and Ogg Vorbis formats as well as many other formats. The FreeBSD Ports Collection also contains applications allowing you to edit your recorded audio, add sound effects, and control attached MIDI devices. With some willingness to experiment, FreeBSD can support playback of video files and DVD's. The number of applications to encode, convert, and playback various video media is more limited than the number of sound applications. For example as of this writing, there is no good re-encoding application in the - FreeBSD Ports Collection, which could be use to interconvert + FreeBSD Ports Collection, which could be use to convert between formats, as there is with audio/sox. However, the software landscape in this area is changing rapidly. This chapter will describe the necessary steps to configure your sound card. The configuration and installation of XFree86 () has already taken care of the hardware issues for your video card, though there may be some tweaks to apply for better playback. After reading this chapter, you will know: How to configure your system so that your sound card is recognized. Methods to test that your card is working using sample applications. How to troubleshoot your sound setup. How to playback and encode MP3s and other audio. How video is supported by XFree86. Some video player/encoder ports which give good results. How to playback DVD's, .mpg and .avi files. How to rip CD and DVD information into files. Before reading this chapter, you should: Know how to configure and install a new kernel (). For the video sections, it is assumed that XFree86 4.X (x11/XFree86-4) has been installed. XFree86 3.X may work, but it has not been tested with what is described in this chapter. If you find that something described here does work with XFree86 3.X please let us know. Trying to mount an audio CD or a video DVD with the &man.mount.8; command will result in an error, at least, and a kernel panic, at worst. These media have specialized encodings which differ from the usual ISO-filesystem. Moses Moore Contributed by Setting Up The Sound Card Locating the Correct Device PCI ISA sound cards Before you begin, you should know the model of the card you have, the chip it uses, and whether it is a PCI or ISA card. FreeBSD supports a wide variety of both PCI and ISA cards. If you do not see your card in the following list, check the &man.pcm.4; manual page. This is not a complete list; however, it does list some of the most common cards. Crystal 4237, 4236, 4232, 4231 Yamaha OPL-SAx OPTi931 Ensoniq AudioPCI 1370/1371 ESS Solo-1/1E NeoMagic 256AV/ZX Sound Blaster Pro, 16, 32, AWE64, AWE128, Live Creative ViBRA16 Advanced Asound 100, 110, and Logic ALS120 ES 1868, 1869, 1879, 1888 Gravis UltraSound Aureal Vortex 1 or 2 kernel configuration To use your sound device, you will need to load the proper device driver. This may be accomplished in one of two ways. The easiest way is to simply load a kernel module for your sound card with &man.kldload.8;. Alternatively, you may statically compile in support for your sound card in your kernel. The sections below provide the information you need to add support for your hardware in this manner. For more information about recompiling your kernel, please see . Creative, Advance, and ESS Sound Cards If you have one of the above cards, you will need to add: device pcm to your kernel configuration file. If you have a PnP ISA card, you will also need to add: device sbc For a non-PnP ISA card, add: device pcm device sbc0 at isa? port 0x220 irq 5 drq 1 flags 0x15 to your kernel configuration file. The settings shown above are the defaults. You may need to change the IRQ or the other settings to match your card. See the &man.sbc.4; manual page for more information. The Sound Blaster Live is not supported under FreeBSD 4.0 without a patch, which this section will not cover. It is recommended that you update to the latest -STABLE before trying to use this card. Gravis UltraSound Cards For a PnP ISA card, you will need to add: device pcm device gusc to your kernel configuration file. If you have a non-PnP ISA card, you will need to add: device pcm device gus0 at isa? port 0x220 irq 5 drq 1 flags 0x13 to your kernel configuration file. You may need to change the IRQ or the other settings to match your card. See the &man.gusc.4; manual page for more information. Crystal Sound Cards For Crystal cards, you will need to add: device pcm device csa to your kernel configuration file. Generic Support For PnP ISA or PCI cards, you will need to add: device pcm to your kernel configuration file. If you have a non-PnP ISA sound card that does not have a bridge driver, you will need to add: device pcm0 at isa? irq 10 drq 1 flags 0x0 to your kernel configuration file. You may need to change the IRQ or the other settings to match your card. Onboard Sound Some systems with built-in motherboard sound devices may require the following option in your kernel configuration: options PNPBIOS Creating and Testing the Device Nodes device nodes After you reboot, log in and check for the device in the /var/run/dmesg.boot file, as shown below: &prompt.root; grep pcm /var/run/dmesg.boot pcm0: <SB16 DSP 4.11> on sbc0 The output from your system may look different. If no pcm devices show up, something went wrong earlier. If that happens, go through your kernel configuration file again and make sure you chose the correct device. Common problems are listed in . If you are running FreeBSD 5.0 or later, you can safely skip the rest of this section. These versions use &man.devfs.5; to automatically create devices nodes. If the previous command returned pcm0, you will have to run the following as root: &prompt.root; cd /dev &prompt.root; sh MAKEDEV snd0 If the command returned pcm1, follow the same steps as shown above, replacing snd0 with snd1. The above commands will not create a /dev/snd device! MAKEDEV will create a group of device nodes, including: Device Description /dev/audio SPARC-compatible audio device /dev/dsp Digitized voice device /dev/dspW Like /dev/dsp, but 16 bits per sample /dev/midi Raw midi access device /dev/mixer Control port mixer device /dev/music Level 2 sequencer interface /dev/sequencer Sequencer device /dev/pss Programmable device interface If all goes well, you should now have a functioning sound card. If your CD-ROM or DVD-ROM drive is properly coupled to your sound card, you can put a CD in the drive and play it with &man.cdcontrol.1;: &prompt.user; cdcontrol -f /dev/acd0c play 1 Various applications, such as audio/workman offer a better interface. You may want to install an application such as audio/mpg123 to listen to MP3 audio files. Common Problems Error Solution device nodes unsupported subdevice XX One or more of the device nodes was not created correctly. Repeat the steps above. I/O port sb_dspwr(XX) timed out The I/O port is not set correctly. IRQ bad irq XX The IRQ is set incorrectly. Make sure that the set IRQ and the sound IRQ are the same. xxx: gus pcm not attached, out of memory There is not enough available memory to use the device. DSP xxx: can't open /dev/dsp! Check with fstat | grep dsp if another application is holding the device open. Noteworthy troublemakers are esound and KDE's sound support. Munish Chopra Contributed by Utilizing Multiple Sound Sources It is often desirable to have multiple sources of sound that are able to play simultaneously, such as when esound or artsd do not support sharing of the sound device with a certain application. FreeBSD lets you do this through Virtual Sound Channels, which can be set with the &man.sysctl.8; facility. Virtual channels allow you to multiplex your sound card's playback channels by mixing sound in the kernel. To set the number of virtual channels, there are two sysctl knobs which, if you are the root user, can be set like this: &prompt.root; sysctl hw.snd.pcm0.vchans=4 &prompt.root; sysctl hw.snd.maxautovchans=4 The above example allocates four virtual channels, which is a practical number for everyday use. hw.snd.pcm0.vchans is the number of virtual channels pcm0 has, and is configurable once a device has been attached. hw.snd.maxautovchans is the number of virtual channels a new audio device is given when it is attached using &man.kldload.8;. Since the pcm module can be loaded independently of the hardware drivers, hw.snd.maxautovchans can store how many virtual channels any devices which are attached later will be given. If you are not using &man.devfs.5;, you will have to point your applications at /dev/dsp0.x, where x is 0 to 3 if hw.snd.pcm.0.vchans is set to 4 as in the above example. On a system using &man.devfs.5;, the above will automatically be allocated transparently to the user. Chern Lee Contributed by MP3 Audio MP3 (MPEG Layer 3 Audio) accomplishes near CD-quality sound, leaving no reason to let your FreeBSD workstation fall short of its offerings. MP3 Players By far, the most popular XFree86 MP3 player is XMMS (X Multimedia System). Winamp skins can be used with XMMS since the GUI is almost identical to that of Nullsoft's Winamp. XMMS also has native plug-in support. XMMS can be installed from the multimedia/xmms port or package. XMMS' interface is intuitive, with a playlist, graphic equalizer, and more. Those familiar with Winamp will find XMMS simple to use. The audio/mpg123 port is an alternative, command-line MP3 player. mpg123 can be run by specifying the sound device and the MP3 file on the command line, as shown below: &prompt.root; mpg123 -a /dev/dsp1.0 Foobar-GreatestHits.mp3 High Performance MPEG 1.0/2.0/2.5 Audio Player for Layer 1, 2 and 3. Version 0.59r (1999/Jun/15). Written and copyrights by Michael Hipp. Uses code from various people. See 'README' for more! THIS SOFTWARE COMES WITH ABSOLUTELY NO WARRANTY! USE AT YOUR OWN RISK! Playing MPEG stream from BT - Foobar-GreastHits.mp3 ... MPEG 1.0 layer III, 128 kbit/s, 44100 Hz joint-stereo /dev/dsp1.0 should be replaced with the dsp device entry on your system. Ripping CD Audio Tracks Before encoding a CD or CD track to MP3, the audio data on the CD must be ripped onto the hard drive. This is done by copying the raw CDDA (CD Digital Audio) data to WAV files. The cdda2wav tool, which is a part of the sysutils/cdrtools suite, is used for ripping audio information from CDs and the information associated with them. With the audio CD in the drive, the following command can be issued (as root) to rip an entire CD into individual (per track) WAV files: &prompt.root; cdda2wav -D 0,1,0 -B cdda2wav will support ATAPI (IDE) CDROM drives. To rip from an IDE drive, specify the device name in place of the SCSI unit numbers. For example, to rip track 7 from an IDE drive: &prompt.root; cdda2wav -D /dev/acd0a -t 7 The indicates the SCSI device 0,1,0, which corresponds to the output of cdrecord -scanbus. To rip individual tracks, make use of the option as shown: &prompt.root; cdda2wav -D 0,1,0 -t 7 This example rips track seven of the audio CDROM. To rip a range of tracks, for example, track one to seven, specify a range: &prompt.root; cdda2wav -D 0,1,0 -t 1+7 The utility &man.dd.1; can also be used to extract audio tracks on ATAPI drives, read for more information on that possibility. Encoding MP3s Nowadays, the mp3 encoder of choice is lame. Lame can be found at audio/lame in the ports tree. Using the ripped WAV files, the following command will convert audio01.wav to audio01.mp3: &prompt.root; lame -h -b 128 \ --tt "Foo Song Title" \ --ta "FooBar Artist" \ --tl "FooBar Album" \ --ty "2001" \ --tc "Ripped and encoded by Foo" \ --tg "Genre" \ audio01.wav audio01.mp3 128 kbits seems to be the standard MP3 bitrate in use. Many enjoy the higher quality 160, or 192. The higher the bitrate, the more disk space the resulting MP3 will consume--but the quality will be higher. The option turns on the higher quality but a little slower mode. The options beginning with indicate ID3 tags, which usually contain song information, to be embedded within the MP3 file. Additional encoding options can be found by consulting the lame man page. Decoding MP3s In order to burn an audio CD from MP3s, they must be converted to a non-compressed WAV format. Both XMMS and mpg123 support the output of MP3 to an uncompressed file format. Writing to Disk in XMMS: Launch XMMS. Right-click on the window to bring up the XMMS menu. Select Preference under Options. Change the Output Plugin to Disk Writer Plugin. Press Configure. Enter (or choose browse) a directory to write the uncompressed files to. Load the MP3 file into XMMS as usual, with volume at 100% and EQ settings turned off. Press PlayXMMS will appear as if it is playing the MP3, but no music will be heard. It is actually playing the MP3 to a file. Be sure to set the default Output Plugin back to what it was before in order to listen to MP3s again. Writing to stdout in mpg123: Run mpg123 -s audio01.mp3 > audio01.pcm XMMS writes a file in the WAV format, while mpg123 converts the MP3 into raw PCM audio data. Both of these formats can be used with cdrecord to create audio CDs. You have to use raw PCM with &man.burncd.8;. If you use WAV files, you will notice a small tick sound at the beginning of each track, this sound is the header of the WAV file. You can simply remove the header of a WAV file with the utility SoX (it can be installed from the audio/sox port or package): &prompt.user; sox -t wav -r 44100 -s -w -c 2 track.wav track.raw Read for more information on using a CD burner in FreeBSD. Ross Lippert Contributed by Video Playback Video playback is a very new and rapidly developing application area. Be patient. Not everything is going to work as smoothly as it did with sound. Before you begin, you should know the model of the video card you have and the chip it uses. While XFree86 supports a wide variety of video cards, fewer give good playback performance. To obtain a list of extensions supported by the X server using your card use the command &man.xdpyinfo.1; while X11 is running. It is a good idea to have a short MPEG file which can be treated as a test file for evaluating various players and options. Since some DVD players will look for DVD media in /dev/dvd by default, or have this device name hardcoded in them, you might find it useful to make symbolic links to the proper devices: &prompt.root; ln -sf /dev/acd0c /dev/dvd &prompt.root; ln -sf /dev/racd0c /dev/rdvd On FreeBSD 5.X, which uses &man.devfs.5; there is a slightly different set of recommended links: &prompt.root; ln -sf /dev/acd0c /dev/dvd &prompt.root; ln -sf /dev/acd0c /dev/rdvd Additionally, DVD decryption, which requires invoking special DVD-ROM functions, requires write permission on the DVD devices. kernel options options CPU_ENABLE_SSE kernel options options USER_LDT Some of the ports discussed rely on the following kernel options to build correctly. Before attempting to build, add these options to the kernel configuration file, build a new kernel, and reboot: option CPU_ENABLE_SSE option USER_LDT To enhance the shared memory X11 interface, it is recommended that the values of some &man.sysctl.8; variables should be increased: kern.ipc.shmmax=67108864 kern.ipc.shmall=32768 Determining Video capabilities XVideo SDL DGA There are several possible ways to display video under X11. What will really work is largely hardware dependent. Each method described below will have varying quality across different hardware. Secondly, the rendering of video in X11 is a topic receiving a lot of attention lately, and with each version of XFree86 there may be significant improvement. A list of common video interfaces: X11: normal X11 output using shared memory. XVideo: an extension to the X11 interface which supports video in any X11 drawable. SDL: the Simple Directmedia Layer. DGA: the Direct Graphics Access. SVGAlib: low level console graphics layer. XVideo XFree86 4.X has an extension called XVideo (aka Xvideo, aka Xv, aka xv) which allows video to be directly displayed in drawable objects through a special acceleration. This extension provides very good quality playback even on low-end machines (for example my PIII 400 Mhz laptop). Unfortunately, the list of cards in which this feature is supported out of the box is currently: 3DFX Voodoo 3 Intel i810 and i815 some S3 chips (such as Savage/IX and Savage/MX) If your card is not one of these, do not be disappointed yet. XFree86 4.X adds new xv capabilities with each release A popular familiar graphics card with generally very good XFree86 performance, nVidia, has yet to release the specifications on their XVideo support to the XFree86 team. It may be some time before XFree86 fully support XVideo for these cards. . To check whether the extension is running, use xvinfo: &prompt.user; xvinfo XVideo is supported for your card if the result looks like: X-Video Extension version 2.2 screen #0 Adaptor #0: "Savage Streams Engine" number of ports: 1 port base: 43 operations supported: PutImage supported visuals: depth 16, visualID 0x22 depth 16, visualID 0x23 number of attributes: 5 "XV_COLORKEY" (range 0 to 16777215) client settable attribute client gettable attribute (current value is 2110) "XV_BRIGHTNESS" (range -128 to 127) client settable attribute client gettable attribute (current value is 0) "XV_CONTRAST" (range 0 to 255) client settable attribute client gettable attribute (current value is 128) "XV_SATURATION" (range 0 to 255) client settable attribute client gettable attribute (current value is 128) "XV_HUE" (range -180 to 180) client settable attribute client gettable attribute (current value is 0) maximum XvImage size: 1024 x 1024 Number of image formats: 7 id: 0x32595559 (YUY2) guid: 59555932-0000-0010-8000-00aa00389b71 bits per pixel: 16 number of planes: 1 type: YUV (packed) id: 0x32315659 (YV12) guid: 59563132-0000-0010-8000-00aa00389b71 bits per pixel: 12 number of planes: 3 type: YUV (planar) id: 0x30323449 (I420) guid: 49343230-0000-0010-8000-00aa00389b71 bits per pixel: 12 number of planes: 3 type: YUV (planar) id: 0x36315652 (RV16) guid: 52563135-0000-0000-0000-000000000000 bits per pixel: 16 number of planes: 1 type: RGB (packed) depth: 0 red, green, blue masks: 0x1f, 0x3e0, 0x7c00 id: 0x35315652 (RV15) guid: 52563136-0000-0000-0000-000000000000 bits per pixel: 16 number of planes: 1 type: RGB (packed) depth: 0 red, green, blue masks: 0x1f, 0x7e0, 0xf800 id: 0x31313259 (Y211) guid: 59323131-0000-0010-8000-00aa00389b71 bits per pixel: 6 number of planes: 3 type: YUV (packed) id: 0x0 guid: 00000000-0000-0000-0000-000000000000 bits per pixel: 0 number of planes: 0 type: RGB (packed) depth: 1 red, green, blue masks: 0x0, 0x0, 0x0 Also note that the formats listed (YUV2, YUV12, etc) are not present with every implementation of XVideo and their absence may hinder some players. If the result looks like: X-Video Extension version 2.2 screen #0 no adaptors present Then XVideo is probably not supported for your card. If XVideo is not supported for your card, this only means that it will be more difficult for your display to meet the computational demands of rendering video. Depending on your video card and processor, though, you might still be able to have a satisfying experience. You should probably read about ways of improving performance in the advanced reading . Simple Directmedia Layer The Simple Directmedia Layer, SDL, was intended to be a porting layers between Microsoft Windows, BeOS, and Unix, allowing cross-platform applications to be developed which made efficient use of sound and graphics. The SDL layer provides a low-level abstraction to the hardware which can sometimes be more efficient than the X11 interface. The SDL can be found at devel/sdl12 Direct Graphics Access Direct Graphics Access is an XFree86 extension which allows a program to bypass the X server and directly alter the framebuffer. Because it relies on a low level memory mapping to effect this sharing, programs using it must must be run as root. The DGA extension can be tested and benchmarked by &man.dga.1;. When dga is running, it changes the colors of the display whenever a key is pressed. To quit, use q. Ports and Packages Dealing with Video video ports video packages This section discusses the software available from the FreeBSD Ports Collection which can be used for video playback. Video playback is a very active area of software development, and the capabilities of various applications are bound to diverge somewhat from the descriptions given here. Firstly, it is important to know that most of the video applications which run on FreeBSD were developed as Linux applications, originating in the past year. For this reason, they are both very experimental and riddled with Linux-isms which might prevent them from working at full efficiency on FreeBSD. By experimental, I mean that you should expect re-encoders, players, and DVD decrypters to have some major bugs, or interoperability problems with other programs. Here is a short list of the sort of things I mean: An application cannot playback a file which another application produced. An application cannot playback a file which the application itself produced. The same application on two different machines, rebuilt on each machine for that machine, plays back the same file differently. A seemingly trivial filter like rescaling of the image size results in very bad artifacts from a buggy rescaling routine. An application always dumping core. Documentation is not installed with the port and can be found either on the web or under PORTPATH/work/ . By Linux-isms, I mean that there are some issues resulting from the way some standard libraries are implemented in the Linux distributions, or some features of the Linux kernel which have been assumed by the authors of the applications, because that is where the authors are primarily developing. These issues may not be noticed and worked around by the port maintainers which can lead to some problems like these: The use of /proc/cpuinfo to detect processor characteristics. A misuse of threads which causes a program to hang upon completion instead of truly terminating. Software not yet in the FreeBSD Ports Collection which is commonly used in conjunction with the application. So far, these application developers have been cooperative with port maintainers to minimize the work-arounds needed for port-ing. MPlayer MPlayer is a recently developed and rapidly developing video player. The goals of the MPlayer team are speed and flexibility on Linux and other Unices. The project was started when the team founder got fed up with bad playback performance on then available players. Some would say that interface has been sacrificed for streamlined design, but once you get used to the command line options and the key-stroke controls, it works very well. Building MPlayer MPlayer making MPlayer resides in multimedia/mplayer. MPlayer performs a variety of hardware checks during the build process, resulting in a binary which will not be portable from one system to another. Therefore, it is important to build it from ports and not to use a binary package. Additionally, a number of options can be specified in the make which echo at the start of the build. &prompt.root; cd /usr/ports/multimedia/mplayer &prompt.root; make You can enable additional compilation optimizations by defining WITH_OPTIMIZED_CFLAGS You can enable GTK GUI by defining WITH_GUI. You can enable DVD support by defining WITH_DVD. You can enable SVGALIB support by defining WITH_SVGALIB. You can enable VORBIS sound support by defining WITH_VORBIS. You can enable XAnim DLL support by defining WITH_XANIM. If you have x11-toolkits/gtk12 installed, then you might as well enable the GUI. Otherwise, it is not worth the effort. If you intend to play (possibly CSS encoded) DVD's with MPlayer you must enable the DVD support option here Unauthorized DVD playback is a serious criminal act in some countries. Check local laws before enabling this option. . Some reasonable options are: &prompt.root; make WITH_DVD=yes WITH_SVGALIB=yes As of this writing, the MPlayer port will build its HTML documentation and one executable, mplayer. It can also be made to build an encoder, mencoder, which is a tool for re-encoding video. A modification to the Makefile can enable it. It may be enabled by default in subsequent versions of the port. The HTML documentation to MPlayer is very informative. If the reader finds the information on video hardware and interfaces in the chapter lacking, the MPlayer documentation is a very thorough alternative. You should definitely take the time to read the documentation of MPlayer, if you are looking for information about video support in Unix. Using MPlayer MPlayer use Any user of MPlayer must set up a .mplayer subdirectory directory of her home directory. To create this necessary subdirectory, you can do the following: &prompt.user; cd /usr/ports/multimedia/mplayer &prompt.user; make install-user The command options for mplayer are listed in the manual page. For even more detail there is HTML documentation. In this section, we will give some of the common use cases. To play from file, such as testfile.avi through one of the various video interfaces set the : &prompt.user; mplayer -vo xv testfile.avi &prompt.user; mplayer -vo sdl testfile.avi &prompt.user; mplayer -vo x11 testfile.avi &prompt.root; mplayer -vo dga testfile.avi &prompt.root; mplayer -vo 'sdl:dga' testfile.avi It is worth trying all of these options, as their relative performance depends on many factors and will vary significantly with hardware. To play from a DVD, replace the testfile.avi with where <N> is the title number to play and DEVICE is the device node for the DVD-ROM. For example, to play title 3 from /dev/dvd: &prompt.root; mplayer -vo dga -dvd 2 /dev/dvd To stop, pause, advance and so on, consult the keybindings, which are output by running mplayer -h or read the manual page. Additional important options for playback are: which engages the fullscreen mode and which helps performance. In order for the mplayer command line to not become too large, the user can create a file .mplayer/config and set default options there: vo=xv fs=yes zoom=yes Finally, mplayer can be used to rip a DVD title into a .vob file. To dump out title 2 from a DVD: &prompt.root; mplayer -dumpstream -dumpfile out.vob -dvd 2 /dev/dvd The output file, out.vob, will be MPEG and can be manipulated by the other packages described in this section. mencoder mencoder If you opt to install mencoder when you build, be forewarned that it is still quite experimental. To use mencoder it is a good idea to familiarize yourself with the options from the HTML documentation. There is a manual page, but it is not very useful without the HTML. There are innumerable ways to improve quality, lower bitrate, and change formats, and some of these tricks may make the difference between good or bad performance. Here are a couple of examples to get you going. First a simple copy: &prompt.user; mencoder input.avi -oac copy -ovc copy -o output.avi It is easy to find examples where the output is unplayable even by mplayer. Thus, if you just want to rip to a file, stick to the in mplayer. To convert input.avi to the MPEG4 codec with MPEG3 audio encoding (audio/lame is required): &prompt.user; mencoder input.avi -oac mp3lame -lameopts br=192 \ -ovc lavc -lavcopts vcodec=mpeg4:vhq -o output.avi This has produced output playable by mplayer and xine. input.avi can be replaced with and run as root to re-encode a DVD title directly. Since you are likely to be dissatisfied with your results the first time around, it is recommended you dump the title to a file and work on the file. The xine Video Player The xine video player is a project of wide scope aiming not only at being an all in one video solution, but also in producing a reusable base library and a modular executable which can be extended with plugins. It comes both as a package and as a port, multimedia/xine. The good news is that the above is pretty much true. The xine player is still very rough around the edges, but it is clearly off to a good start. In practice, xine requires either a fast CPU with a fast video card, or support for the XVideo extension. The GUI is usable, but a bit clumsy. As of this writing, there is no input module shipped with xine which will play CSS encoded DVD's. There are third party builds which do have modules for this built in them, but none of these are in the FreeBSD Ports Collection. Compared to MPlayer, xine does more for the user, but at the same time, takes some of the more fine-grained control away from the user. The xine video player also may perform much worse on the non-XVideo interfaces and has very few good alternatives to it. The xine FAQ highly recommends that you have a video card which supports it. The xine player can be started by itself: &prompt.user; xine The menus can then be used to open a file, or it can be started to play a file immediately without the GUI with the command: &prompt.user; xine -g -p mymovie.avi The transcode utilities The software transcode is not a player, but a suite of tools for re-encoding .avi and .mpg files. With transcode, one has the ability to merge video files, repair broken files, using command line tools with stdin/stdout stream interfaces. Like MPlayer, transcode is very experimental software which must be build from the port graphics/transcode. Using a great many options to the make command. I recommend: &prompt.root; make WITH_LIBMPEG2=yes If you plan to install multimedia/avifile, then add the WITH_AVIFILE option to your make command line, as shown here: &prompt.root; make WITH_AVIFILE=yes WITH_LIBMPEG2=yes Here are two examples of using transcode for video conversion which produce rescaled output. The first encodes the output to an openDIVX AVI file, while the second encodes to the much more portable MPEG format. &prompt.user; transcode -i input.vob -x vob -V -Z 320x240 \ -y opendivx -N 0x55 -o output.avi &prompt.user; transcode -i input.vob -x vob -V -Z 320x240 \ -y mpeg -N 0x55 -o output.tmp &prompt.user; tcmplex -o output.mpg -i output.tmp.m1v -p output.tmp.mpa -m 1 There is a manual page for transcode, but for the various tc* utilities (such as tcmplex) which are also installed, there is only a curt output. In comparison, transcode runs significantly slower than mencoder, but it has a better chance of producing a more widely playable file. I can play transcode MPEGs on older copies of Windows Media Player and Apple's Quicktime, for example. Further Reading I have no doubt that within a year, much that is in this chapter will be out of date. Video will probably be much less problematic to get working well and a port will be in the collection which turns a FreeBSD system into a DVD-playing, PVR, and virtual A/V studio. Until that day arrives, those who want to get the very most out of FreeBSD's A/V capabilities will have to cobble together knowledge from several FAQs and tutorials and use a few different applications. This section exists to give the reader some links to learn more in case this chapter was just helpful enough. The MPlayer documentation is very technically informative. These documents should probably be consulted by anyone wishing to obtain a high level of expertise with Unix video. The MPlayer mailing list is hostile to anyone who has not bothered to read the documentation, so if you plan on making bug reports to them, RTFM. The xine HOWTO contains a chapter on performance improvement which is general to all players. Finally, there are some other promising applications which the reader may try: Avifile which is also a port multimedia/avifile. Ogle which is also a port multimedia/ogle. Xtheater diff --git a/en_US.ISO8859-1/books/handbook/vinum/chapter.sgml b/en_US.ISO8859-1/books/handbook/vinum/chapter.sgml index 86e417a29a..c955721cf1 100644 --- a/en_US.ISO8859-1/books/handbook/vinum/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/vinum/chapter.sgml @@ -1,1453 +1,1453 @@ The Vinum Volume Manager Synopsis No matter what disks you have, there will always be limitations: They can be too small. They can be too slow. They can be too unreliable. Greg Lehey Originally written by Disks Are Too Small Vinum RAID Software Vinum is a so-called Volume Manager, a virtual disk driver that addresses these three problems. Let us look at them in more detail. Various solutions to these problems have been proposed and implemented: Disks are getting bigger, but so are data storage requirements. Often you will find you want a file system that is bigger than the disks you have available. Admittedly, this problem is not as acute as it was ten years ago, but it still exists. Some systems have solved this by creating an abstract device which stores its data on a number of disks. Access Bottlenecks Modern systems frequently need to access data in a highly concurrent manner. For example, large FTP or HTTP servers can maintain thousands of concurrent sessions and have multiple 100 Mbit/s connections to the outside world, well beyond the sustained transfer rate of most disks. Current disk drives can transfer data sequentially at up to 70 MB/s, but this value is of little importance in an environment where many independent processes access a drive, where they may achieve only a fraction of these values. In such cases it is more interesting to view the problem from the viewpoint of the disk subsystem: the important parameter is the load that a transfer places on the subsystem, in other words the time for which a transfer occupies the drives involved in the transfer. In any disk transfer, the drive must first position the heads, wait for the first sector to pass under the read head, and then perform the transfer. These actions can be considered to be atomic: it does not make any sense to interrupt them. Consider a typical transfer of about 10 kB: the current generation of high-performance disks can position the heads in an average of 3.5 ms. The fastest drives spin at 15,000 rpm, so the average rotational latency (half a revolution) is 2 ms. At 70 MB/s, the transfer itself takes about 150 μs, almost nothing compared to the positioning time. In such a case, the effective transfer rate drops to a little over 1 MB/s and is clearly highly dependent on the transfer size. The traditional and obvious solution to this bottleneck is more spindles: rather than using one large disk, it uses several smaller disks with the same aggregate storage space. Each disk is capable of positioning and transferring independently, so the effective throughput increases by a factor close to the number of disks used. The exact throughput improvement is, of course, smaller than the number of disks involved: although each drive is capable of transferring in parallel, there is no way to ensure that the requests are evenly distributed across the drives. Inevitably the load on one drive will be higher than on another. disk concatenation Vinum concatenation The evenness of the load on the disks is strongly dependent on the way the data is shared across the drives. In the following discussion, it is convenient to think of the disk storage as a large number of data sectors which are addressable by number, rather like the pages in a book. The most obvious method is to divide the virtual disk into groups of consecutive sectors the size of the individual physical disks and store them in this manner, rather like taking a large book and tearing it into smaller sections. This method is called concatenation and has the advantage that the disks are not required to have any specific size relationships. It works well when the access to the virtual disk is spread evenly about its address space. When access is concentrated on a smaller area, the improvement is less marked. illustrates the sequence in which storage units are allocated in a concatenated organization.
Concatenated Organization
disk striping Vinum striping An alternative mapping is to divide the address space into smaller, equal-sized components and store them sequentially on different devices. For example, the first 256 sectors may be stored on the first disk, the next 256 sectors on the next disk and so on. After filling the last disk, the process repeats until the disks are full. This mapping is called striping or RAID-0 RAID RAID stands for Redundant Array of Inexpensive Disks and offers various forms of fault tolerance, though the latter term is somewhat misleading: it provides no redundancy. . Striping requires somewhat more effort to locate the data, and it can cause additional I/O load where a transfer is spread over multiple disks, but it can also provide a more constant load across the disks. illustrates the sequence in which storage units are allocated in a striped organization.
Striped Organization
Data Integrity The final problem with current disks is that they are unreliable. Although disk drive reliability has increased tremendously over the last few years, they are still the most likely core component of a server to fail. When they do, the results can be catastrophic: replacing a failed disk drive and restoring data to it can take days. disk mirroring Vinum mirroring RAID-1 The traditional way to approach this problem has been mirroring, keeping two copies of the data on different physical hardware. Since the advent of the RAID levels, this technique has also been called RAID level 1 or RAID-1. Any write to the volume writes to both locations; a read can be satisfied from either, so if one drive fails, the data is still available on the other drive. Mirroring has two problems: The price. It requires twice as much disk storage as a non-redundant solution. The performance impact. Writes must be performed to both drives, so they take up twice the bandwidth of a non-mirrored volume. Reads do not suffer from a performance penalty: it even looks as if they are faster. RAID-5An alternative solution is parity, implemented in the RAID levels 2, 3, 4 and 5. Of these, RAID-5 is the most interesting. As implemented in Vinum, it is a variant on a striped organization which dedicates one block of each stripe to parity of the other blocks. As implemented by Vinum, a RAID-5 plex is similar to a striped plex, except that it implements RAID-5 by including a parity block in each stripe. As required by RAID-5, the location of this parity block changes from one stripe to the next. The numbers in the data blocks indicate the relative block numbers.
RAID-5 Organization
Compared to mirroring, RAID-5 has the advantage of requiring significantly less storage space. Read access is similar to that of striped organizations, but write access is significantly slower, approximately 25% of the read performance. If one drive fails, the array can continue to operate in degraded mode: a read from one of the remaining accessible drives continues normally, but a read from the failed drive is recalculated from the corresponding block from all the remaining drives.
Vinum Objects In order to address these problems, Vinum implements a four-level hierarchy of objects: The most visible object is the virtual disk, called a volume. Volumes have essentially the same properties as a UNIX™ disk drive, though there are some minor differences. They have no size limitations. Volumes are composed of plexes, each of which represent the total address space of a volume. This level in the hierarchy thus provides redundancy. Think of plexes as individual disks in a mirrored array, each containing the same data. Since Vinum exists within the UNIX™ disk storage framework, it would be possible to use UNIX™ partitions as the building block for multi-disk plexes, but in fact this turns out to be too inflexible: UNIX™ disks can have only a limited number of partitions. Instead, Vinum subdivides a single UNIX™ partition (the drive) into contiguous areas called subdisks, which it uses as building blocks for plexes. Subdisks reside on Vinum drives, currently UNIX™ partitions. Vinum drives can contain any number of subdisks. With the exception of a small area at the beginning of the drive, which is used for storing configuration and state information, the entire drive is available for data storage. The following sections describe the way these objects provide the functionality required of Vinum. Volume Size Considerations Plexes can include multiple subdisks spread over all drives in the Vinum configuration. As a result, the size of an individual drive does not limit the size of a plex, and thus of a volume. Redundant Data Storage Vinum implements mirroring by attaching multiple plexes to a volume. Each plex is a representation of the data in a volume. A volume may contain between one and eight plexes. Although a plex represents the complete data of a volume, it is possible for parts of the representation to be physically missing, either by design (by not defining a subdisk for parts of the plex) or by accident (as a result of the failure of a drive). As long as at least one plex can provide the data for the complete address range of the volume, the volume is fully functional. Performance Issues Vinum implements both concatenation and striping at the plex level: A concatenated plex uses the address space of each subdisk in turn. A striped plex stripes the data across each subdisk. The subdisks must all have the same size, and there must be at least two subdisks in order to distinguish it from a concatenated plex. Which Plex Organization? The version of Vinum supplied with FreeBSD &rel.current; implements two kinds of plex: Concatenated plexes are the most flexible: they can contain any number of subdisks, and the subdisks may be of different length. The plex may be extended by adding additional subdisks. They require less CPU time than striped plexes, though the difference in CPU overhead is not measurable. On the other hand, they are most susceptible to hot spots, where one disk is very active and others are idle. The greatest advantage of striped (RAID-0) plexes is that they reduce hot spots: by choosing an optimum sized stripe (about 256 kB), you can even out the load on the component drives. The disadvantages of this approach are (fractionally) more complex code and restrictions on subdisks: they must be all the same size, and extending a plex by adding new subdisks is so complicated that Vinum currently does not implement it. Vinum imposes an additional, trivial restriction: a striped plex must have at least two subdisks, since otherwise it is indistinguishable from a concatenated plex. summarizes the advantages and disadvantages of each plex organization. Vinum Plex Organizations Plex type Minimum subdisks Can add subdisks Must be equal size Application concatenated 1 yes no Large data storage with maximum placement flexibility and moderate performance striped 2 no yes High performance in combination with highly concurrent access
Some Examples Vinum maintains a configuration database which describes the objects known to an individual system. Initially, the user creates the configuration database from one or more configuration files with the aid of the &man.vinum.8; utility program. Vinum stores a copy of its configuration database on each disk slice (which Vinum calls a device) under its control. This database is updated on each state change, so that a restart accurately restores the state of each Vinum object. The Configuration File The configuration file describes individual Vinum objects. The definition of a simple volume might be: drive a device /dev/da3h volume myvol plex org concat sd length 512m drive a This file describes four Vinum objects: The drive line describes a disk partition (drive) and its location relative to the underlying hardware. It is given the symbolic name a. This separation of the symbolic names from the device names allows disks to be moved from one location to another without confusion. The volume line describes a volume. The only required attribute is the name, in this case myvol. The plex line defines a plex. The only required parameter is the organization, in this case concat. No name is necessary: the system automatically generates a name from the volume name by adding the suffix .px, where x is the number of the plex in the volume. Thus this plex will be called myvol.p0. The sd line describes a subdisk. The minimum specifications are the name of a drive on which to store it, and the length of the subdisk. As with plexes, no name is necessary: the system automatically assigns names derived from the plex name by adding the suffix .sx, where x is the number of the subdisk in the plex. Thus Vinum gives this subdisk the name myvol.p0.s0. After processing this file, &man.vinum.8; produces the following output: &prompt.root; vinum -> create config1 Configuration summary Drives: 1 (4 configured) Volumes: 1 (4 configured) Plexes: 1 (8 configured) Subdisks: 1 (16 configured) D a State: up Device /dev/da3h Avail: 2061/2573 MB (80%) V myvol State: up Plexes: 1 Size: 512 MB P myvol.p0 C State: up Subdisks: 1 Size: 512 MB S myvol.p0.s0 State: up PO: 0 B Size: 512 MB This output shows the brief listing format of &man.vinum.8;. It is represented graphically in .
A Simple Vinum Volume
This figure, and the ones which follow, represent a volume, which contains the plexes, which in turn contain the subdisks. In this trivial example, the volume contains one plex, and the plex contains one subdisk. This particular volume has no specific advantage over a conventional disk partition. It contains a single plex, so it is not redundant. The plex contains a single subdisk, so there is no difference in storage allocation from a conventional disk partition. The following sections illustrate various more interesting configuration methods.
Increased Resilience: Mirroring The resilience of a volume can be increased by mirroring. When laying out a mirrored volume, it is important to ensure that the subdisks of each plex are on different drives, so that a drive failure will not take down both plexes. The following configuration mirrors a volume: drive b device /dev/da4h volume mirror plex org concat sd length 512m drive a plex org concat sd length 512m drive b In this example, it was not necessary to specify a definition of drive a again, since Vinum keeps track of all objects in its configuration database. After processing this definition, the configuration looks like: Drives: 2 (4 configured) Volumes: 2 (4 configured) Plexes: 3 (8 configured) Subdisks: 3 (16 configured) D a State: up Device /dev/da3h Avail: 1549/2573 MB (60%) D b State: up Device /dev/da4h Avail: 2061/2573 MB (80%) V myvol State: up Plexes: 1 Size: 512 MB V mirror State: up Plexes: 2 Size: 512 MB P myvol.p0 C State: up Subdisks: 1 Size: 512 MB P mirror.p0 C State: up Subdisks: 1 Size: 512 MB P mirror.p1 C State: initializing Subdisks: 1 Size: 512 MB S myvol.p0.s0 State: up PO: 0 B Size: 512 MB S mirror.p0.s0 State: up PO: 0 B Size: 512 MB S mirror.p1.s0 State: empty PO: 0 B Size: 512 MB shows the structure graphically.
A Mirrored Vinum Volume
In this example, each plex contains the full 512 MB of address space. As in the previous example, each plex contains only a single subdisk.
Optimizing Performance The mirrored volume in the previous example is more resistant to failure than an unmirrored volume, but its performance is less: each write to the volume requires a write to both drives, using up a greater proportion of the total disk bandwidth. Performance considerations demand a different approach: instead of mirroring, the data is striped across as many disk drives as possible. The following configuration shows a volume with a plex striped across four disk drives: drive c device /dev/da5h drive d device /dev/da6h volume stripe plex org striped 512k sd length 128m drive a sd length 128m drive b sd length 128m drive c sd length 128m drive d As before, it is not necessary to define the drives which are already known to Vinum. After processing this definition, the configuration looks like: Drives: 4 (4 configured) Volumes: 3 (4 configured) Plexes: 4 (8 configured) Subdisks: 7 (16 configured) D a State: up Device /dev/da3h Avail: 1421/2573 MB (55%) D b State: up Device /dev/da4h Avail: 1933/2573 MB (75%) D c State: up Device /dev/da5h Avail: 2445/2573 MB (95%) D d State: up Device /dev/da6h Avail: 2445/2573 MB (95%) V myvol State: up Plexes: 1 Size: 512 MB V mirror State: up Plexes: 2 Size: 512 MB V striped State: up Plexes: 1 Size: 512 MB P myvol.p0 C State: up Subdisks: 1 Size: 512 MB P mirror.p0 C State: up Subdisks: 1 Size: 512 MB P mirror.p1 C State: initializing Subdisks: 1 Size: 512 MB P striped.p1 State: up Subdisks: 1 Size: 512 MB S myvol.p0.s0 State: up PO: 0 B Size: 512 MB S mirror.p0.s0 State: up PO: 0 B Size: 512 MB S mirror.p1.s0 State: empty PO: 0 B Size: 512 MB S striped.p0.s0 State: up PO: 0 B Size: 128 MB S striped.p0.s1 State: up PO: 512 kB Size: 128 MB S striped.p0.s2 State: up PO: 1024 kB Size: 128 MB S striped.p0.s3 State: up PO: 1536 kB Size: 128 MB
A Striped Vinum Volume
This volume is represented in . The darkness of the stripes indicates the position within the plex address space: the lightest stripes come first, the darkest last.
Resilience and Performance With sufficient hardware, it is possible to build volumes which show both increased resilience and increased performance compared to standard UNIX™ partitions. A typical configuration file might be: volume raid10 plex org striped 512k sd length 102480k drive a sd length 102480k drive b sd length 102480k drive c sd length 102480k drive d sd length 102480k drive e plex org striped 512k sd length 102480k drive c sd length 102480k drive d sd length 102480k drive e sd length 102480k drive a sd length 102480k drive b The subdisks of the second plex are offset by two drives from those of the first plex: this helps ensure that writes do not go to the same subdisks even if a transfer goes over two drives. represents the structure of this volume.
A Mirrored, Striped Vinum Volume
Object Naming As described above, Vinum assigns default names to plexes and subdisks, although they may be overridden. Overriding the default names is not recommended: experience with the VERITAS volume manager, which allows arbitrary naming of objects, has shown that this flexibility does not bring a significant advantage, and it can cause confusion. Names may contain any non-blank character, but it is recommended to restrict them to letters, digits and the underscore characters. The names of volumes, plexes and subdisks may be up to 64 characters long, and the names of drives may be up to 32 characters long. Vinum objects are assigned device nodes in the hierarchy /dev/vinum. The configuration shown above would cause Vinum to create the following device nodes: The control devices /dev/vinum/control and /dev/vinum/controld, which are used by &man.vinum.8; and the Vinum daemon respectively. Block and character device entries for each volume. These are the main devices used by Vinum. The block device names are the name of the volume, while the character device names follow the BSD tradition of prepending the letter r to the name. Thus the configuration above would include the block devices /dev/vinum/myvol, /dev/vinum/mirror, /dev/vinum/striped, /dev/vinum/raid5 and /dev/vinum/raid10, and the character devices /dev/vinum/rmyvol, /dev/vinum/rmirror, /dev/vinum/rstriped, /dev/vinum/rraid5 and /dev/vinum/rraid10. There is obviously a problem here: it is possible to have two volumes called r and rr, but there will be a conflict creating the device node /dev/vinum/rr: is it a character device for volume r or a block device for volume rr? Currently Vinum does not address this conflict: the first-defined volume will get the name. A directory /dev/vinum/drive with entries for each drive. These entries are in fact symbolic links to the corresponding disk nodes. A directory /dev/vinum/volume with entries for each volume. It contains subdirectories for each plex, which in turn contain subdirectories for their component subdisks. The directories /dev/vinum/plex, /dev/vinum/sd, and /dev/vinum/rsd, which contain block device nodes for each plex and block and character device nodes respectively for each subdisk. For example, consider the following configuration file: drive drive1 device /dev/sd1h drive drive2 device /dev/sd2h drive drive3 device /dev/sd3h drive drive4 device /dev/sd4h volume s64 setupstate plex org striped 64k sd length 100m drive drive1 sd length 100m drive drive2 sd length 100m drive drive3 sd length 100m drive drive4 After processing this file, &man.vinum.8; creates the following structure in /dev/vinum: brwx------ 1 root wheel 25, 0x40000001 Apr 13 16:46 Control brwx------ 1 root wheel 25, 0x40000002 Apr 13 16:46 control brwx------ 1 root wheel 25, 0x40000000 Apr 13 16:46 controld drwxr-xr-x 2 root wheel 512 Apr 13 16:46 drive drwxr-xr-x 2 root wheel 512 Apr 13 16:46 plex crwxr-xr-- 1 root wheel 91, 2 Apr 13 16:46 rs64 drwxr-xr-x 2 root wheel 512 Apr 13 16:46 rsd drwxr-xr-x 2 root wheel 512 Apr 13 16:46 rvol brwxr-xr-- 1 root wheel 25, 2 Apr 13 16:46 s64 drwxr-xr-x 2 root wheel 512 Apr 13 16:46 sd drwxr-xr-x 3 root wheel 512 Apr 13 16:46 vol /dev/vinum/drive: total 0 lrwxr-xr-x 1 root wheel 9 Apr 13 16:46 drive1 -> /dev/sd1h lrwxr-xr-x 1 root wheel 9 Apr 13 16:46 drive2 -> /dev/sd2h lrwxr-xr-x 1 root wheel 9 Apr 13 16:46 drive3 -> /dev/sd3h lrwxr-xr-x 1 root wheel 9 Apr 13 16:46 drive4 -> /dev/sd4h /dev/vinum/plex: total 0 brwxr-xr-- 1 root wheel 25, 0x10000002 Apr 13 16:46 s64.p0 /dev/vinum/rsd: total 0 crwxr-xr-- 1 root wheel 91, 0x20000002 Apr 13 16:46 s64.p0.s0 crwxr-xr-- 1 root wheel 91, 0x20100002 Apr 13 16:46 s64.p0.s1 crwxr-xr-- 1 root wheel 91, 0x20200002 Apr 13 16:46 s64.p0.s2 crwxr-xr-- 1 root wheel 91, 0x20300002 Apr 13 16:46 s64.p0.s3 /dev/vinum/rvol: total 0 crwxr-xr-- 1 root wheel 91, 2 Apr 13 16:46 s64 /dev/vinum/sd: total 0 brwxr-xr-- 1 root wheel 25, 0x20000002 Apr 13 16:46 s64.p0.s0 brwxr-xr-- 1 root wheel 25, 0x20100002 Apr 13 16:46 s64.p0.s1 brwxr-xr-- 1 root wheel 25, 0x20200002 Apr 13 16:46 s64.p0.s2 brwxr-xr-- 1 root wheel 25, 0x20300002 Apr 13 16:46 s64.p0.s3 /dev/vinum/vol: total 1 brwxr-xr-- 1 root wheel 25, 2 Apr 13 16:46 s64 drwxr-xr-x 3 root wheel 512 Apr 13 16:46 s64.plex /dev/vinum/vol/s64.plex: total 1 brwxr-xr-- 1 root wheel 25, 0x10000002 Apr 13 16:46 s64.p0 drwxr-xr-x 2 root wheel 512 Apr 13 16:46 s64.p0.sd /dev/vinum/vol/s64.plex/s64.p0.sd: total 0 brwxr-xr-- 1 root wheel 25, 0x20000002 Apr 13 16:46 s64.p0.s0 brwxr-xr-- 1 root wheel 25, 0x20100002 Apr 13 16:46 s64.p0.s1 brwxr-xr-- 1 root wheel 25, 0x20200002 Apr 13 16:46 s64.p0.s2 brwxr-xr-- 1 root wheel 25, 0x20300002 Apr 13 16:46 s64.p0.s3 Although it is recommended that plexes and subdisks should not be allocated specific names, Vinum drives must be named. This makes it possible to move a drive to a different location and still recognize it automatically. Drive names may be up to 32 characters long. Creating File Systems Volumes appear to the system to be identical to disks, with one exception. Unlike UNIX™ drives, Vinum does not partition volumes, which thus do not contain a partition table. This has required modification to some disk utilities, notably &man.newfs.8;, which previously tried to interpret the last letter of a Vinum volume name as a partition identifier. For example, a disk drive may have a name like /dev/ad0a or /dev/da2h. These names represent the first partition (a) on the first (0) IDE disk (ad) and the eighth partition (h) on the third (2) SCSI disk (da) respectively. By contrast, a Vinum volume might be called /dev/vinum/concat, a name which has no relationship with a partition name. Normally, &man.newfs.8; interprets the name of the disk and complains if it cannot understand it. For example: &prompt.root; newfs /dev/vinum/concat newfs: /dev/vinum/concat: can't figure out file system partition The following is only valid for FreeBSD versions prior to 5.0: In order to create a file system on this volume, use the option to &man.newfs.8;: &prompt.root; newfs -v /dev/vinum/concat Configuring Vinum The GENERIC kernel does not contain Vinum. It is possible to build a special kernel which includes Vinum, but this is not recommended. The standard way to start Vinum is as a kernel module (kld). You do not even need to use &man.kldload.8; for Vinum: when you start &man.vinum.8;, it checks whether the module has been loaded, and if it is not, it loads it automatically. Startup Vinum stores configuration information on the disk slices in essentially the same form as in the configuration files. When reading from the configuration database, Vinum recognizes a number of keywords which are not allowed in the configuration files. For example, a disk configuration might contain the following text: volume myvol state up volume bigraid state down plex name myvol.p0 state up org concat vol myvol plex name myvol.p1 state up org concat vol myvol plex name myvol.p2 state init org striped 512b vol myvol plex name bigraid.p0 state initializing org raid5 512b vol bigraid sd name myvol.p0.s0 drive a plex myvol.p0 state up len 1048576b driveoffset 265b plexoffset 0b sd name myvol.p0.s1 drive b plex myvol.p0 state up len 1048576b driveoffset 265b plexoffset 1048576b sd name myvol.p1.s0 drive c plex myvol.p1 state up len 1048576b driveoffset 265b plexoffset 0b sd name myvol.p1.s1 drive d plex myvol.p1 state up len 1048576b driveoffset 265b plexoffset 1048576b sd name myvol.p2.s0 drive a plex myvol.p2 state init len 524288b driveoffset 1048841b plexoffset 0b sd name myvol.p2.s1 drive b plex myvol.p2 state init len 524288b driveoffset 1048841b plexoffset 524288b sd name myvol.p2.s2 drive c plex myvol.p2 state init len 524288b driveoffset 1048841b plexoffset 1048576b sd name myvol.p2.s3 drive d plex myvol.p2 state init len 524288b driveoffset 1048841b plexoffset 1572864b sd name bigraid.p0.s0 drive a plex bigraid.p0 state initializing len 4194304b driveoff set 1573129b plexoffset 0b sd name bigraid.p0.s1 drive b plex bigraid.p0 state initializing len 4194304b driveoff set 1573129b plexoffset 4194304b sd name bigraid.p0.s2 drive c plex bigraid.p0 state initializing len 4194304b driveoff set 1573129b plexoffset 8388608b sd name bigraid.p0.s3 drive d plex bigraid.p0 state initializing len 4194304b driveoff set 1573129b plexoffset 12582912b sd name bigraid.p0.s4 drive e plex bigraid.p0 state initializing len 4194304b driveoff set 1573129b plexoffset 16777216b The obvious differences here are the presence of explicit location information and naming (both of which are also allowed, but discouraged, for use by the user) and the information on the states (which are not available to the user). Vinum does not store information about drives in the configuration information: it finds the drives by scanning the configured disk drives for partitions with a Vinum label. This enables Vinum to identify drives correctly even if they have been assigned different UNIX™ drive IDs. Automatic Startup In order to start Vinum automatically when you boot the system, ensure that you have the following line in your /etc/rc.conf: start_vinum="YES" # set to YES to start vinum If you do not have a file /etc/rc.conf, create one with this content. This will cause the system to load the Vinum kld at startup, and to start any objects mentioned in the configuration. This is done before mounting file systems, so it is possible to automatically &man.fsck.8; and mount file systems on Vinum volumes. When you start Vinum with the vinum start command, Vinum reads the configuration database from one of the Vinum drives. Under normal circumstances, each drive contains an identical copy of the configuration database, so it does not matter which drive is read. After a crash, however, Vinum must determine which drive was updated most recently and read the configuration from this drive. It then updates the configuration if necessary from progressively older drives. Using Vinum for the root filesystem For a machine that has fully-mirrored filesystems using Vinum, it is desirable to also mirror the root filesystem. Setting up such a configuration is less trivial than mirroring an arbitrary filesystem because: The root filesystem must be available very early during the boot process, so the Vinum infrastructure must already be available at this time. The volume containing the root filesystem also contains the system bootstrap and the kernel, which must be read - using the host system's native utilites (e. g. the BIOS on + using the host system's native utilities (e. g. the BIOS on PC-class machines) which often cannot be taught about the details of Vinum. In the following sections, the term root volume is generally used to describe the Vinum volume that contains the root filesystem. It is probably a good idea to use the name "root" for this volume, but this is not technically required in any way. All command examples in the following sections assume this name though. Starting up Vinum early enough for the root filesystem There are several measures to take for this to happen: Vinum must be available in the kernel at boot-time. Thus, the method to start Vinum automatically described in is not applicable to accomplish this task, and the start_vinum parameter must actually not be set when the following setup is being arranged. The first option would be to compile Vinum statically into the kernel, so it is available all the time, but this is usually not desirable. There is another option as well, to have /boot/loader () load the vinum kernel module early, before starting the kernel. This can be accomplished by putting the line vinum_load="YES" into the file /boot/loader.conf. Vinum must be initialized early since it needs to supply the volume for the root filesystem. By default, the Vinum kernel part is not looking for drives that might contain Vinum volume information until the administrator (or one of the startup scripts) issues a vinum start command. The following paragraphs are outlining the steps needed for FreeBSD 5.x and above. The setup required for FreeBSD 4.x differs, and is described below in . By placing the line: vinum.autostart="YES" into /boot/loader.conf, Vinum is instructed to automatically scan all drives for Vinum information as part of the kernel startup. Note that it is not necessary to instruct the kernel where to look for the root filesystem. /boot/loader looks up the name of the root device in /etc/fstab, and passes this information on to the kernel. When it comes to mount the root filesystem, the kernel figures out from the devicename provided which driver to ask to translate this into the internal device ID (major/minor number). Making a Vinum-based root volume accessible to the bootstrap Since the current FreeBSD bootstrap is only 7.5 KB of code, and already has the burden of reading files (like /boot/loader) from the UFS filesystem, it is sheer impossible to also teach it about internal Vinum structures so it could parse the Vinum configuration data, and figure out about the elements of a boot volume itself. Thus, some tricks are necessary to provide the bootstrap code with the illusion of a standard "a" partition that contains the root filesystem. For this to be possible at all, the following requirements must be met for the root volume: The root volume must not be striped or RAID-5. The root volume must not contain more than one concatenated subdisk per plex. Note that it is desirable and possible that there are multiple plexes, each containing one replica of the root filesystem. The bootstrap process will, however, only use one of these replica for finding the bootstrap and all the files, until the kernel will eventually mount the root filesystem itself. Each single subdisk within these plexes will then need its own "a" partition illusion, for the respective device to become bootable. It is not strictly needed that each of these faked "a" partitions is located at the same offset within its device, compared with other devices containing plexes of the root volume. However, it is probably a good idea to create the Vinum volumes that way so the resulting mirrored devices are symmetric, to avoid confusion. In order to setup these "a" partitions, for each device containing part of the root volume, the following needs to be done: The location (offset from the beginning of the device) and size of this device's subdisk that is part of the root volume need to be examined, using the command vinum l -rv root Note that Vinum offsets and sizes are measured in bytes. They must be divided by 512 in order to obtain the block numbers that are to be used in the disklabel command. Run the command disklabel -e devname for each device that participates in the root volume. devname must be either the name of the disk (like da0) for disks without a slice (aka. fdisk) table, or the name of the slice (like ad0s1). If there is already an "a" partition on the device (presumably, containing a pre-Vinum root filesystem), it should be renamed to something else, so it remains accessible (just in case), but will no longer be used by default to bootstrap the system. Note that active partitions (like a root filesystem currently mounted) cannot be renamed, so this must be executed either when being booted from a Fixit medium, or in a two-step process, where (in a mirrored situation) the disk that has not been currently booted is being manipulated first. Then, the offset the Vinum partition on this device (if any) must be added to the offset of the respective root volume subdisk on this device. The resulting value will become the "offset" value for the new "a" partition. The "size" value for this partition can be taken verbatim from the calculation above. The "fstype" should be 4.2BSD. The "fsize", "bsize", and "cpg" values should best be chosen to match the actual filesystem, though they are fairly unimportant within this context. That way, a new "a" partition will be established that overlaps the Vinum partition on this device. Note that the disklabel will only allow for this overlap if the Vinum partition has properly been marked using the "vinum" fstype. That's all! A faked "a" partition does exist now on each device that has one replica of the root volume. It is highly recommendable to verify the result again, using a command like fsck -n /dev/devnamea It should be remembered that all files containing control information must be relative to the root filesystem in the Vinum volume which, when setting up a new Vinum root volume, might not match the root filesystem that is currently active. So in particular, the files /etc/fstab and /boot/loader.conf need to be taken care of. At next reboot, the bootstrap should figure out the appropriate control information from the new Vinum-based root filesystem, and act accordingly. At the end of the kernel initialization process, after all devices have been announced, the prominent notice that shows the success of this setup is a message like: Mounting root from ufs:/dev/vinum/root Example of a Vinum-based root setup After the Vinum root volume has been set up, the output of vinum l -rv root could look like: ... Subdisk root.p0.s0: Size: 125829120 bytes (120 MB) State: up Plex root.p0 at offset 0 (0 B) Drive disk0 (/dev/da0h) at offset 135680 (132 kB) Subdisk root.p1.s0: Size: 125829120 bytes (120 MB) State: up Plex root.p1 at offset 0 (0 B) Drive disk1 (/dev/da1h) at offset 135680 (132 kB) The values to note are 135680 for the offset (relative to partition /dev/da0h). This translates to 265 512-byte disk blocks in disklabel's terms. Likewise, the size of this root volume is 245760 512-byte blocks. /dev/da1h, containing the second replica of this root volume, has a symmetric setup. The disklabel for these devices might look like: ... 8 partitions: # size offset fstype [fsize bsize bps/cpg] a: 245760 281 4.2BSD 2048 16384 0 # (Cyl. 0*- 15*) c: 71771688 0 unused 0 0 # (Cyl. 0 - 4467*) h: 71771672 16 vinum # (Cyl. 0*- 4467*) It can be observed that the "size" parameter for the faked "a" partition matches the value outlined above, while the "offset" parameter is the sum of the offset within the Vinum partition "h", and the offset of this partition within the device (or slice). This is a typical setup that is necessary to avoid the problem described in . It can also be seen that the entire "a" partition is completely within the "h" partition containing all the Vinum data for this device. Note that in the above example, the entire device is dedicated to Vinum, and there is no leftover pre-Vinum root partition, since this has been a newly set-up disk that was only meant to be part of a Vinum configuration, ever. Troubleshooting If something goes wrong, a way is needed to recover from the situation. The following list contains few known pitfalls and solutions. System bootstrap loads, but system does not boot If for any reason the system does not continue to boot, the bootstrap can be interrupted with by pressing the space key at the 10-seconds warning. The loader variables (like vinum.autostart) can be examined using the show, and manipulated using set or unset commands. If the only problem was that the Vinum kernel module was not yet in the list of modules to load automatically, a simple load vinum will help. When ready, the boot process can be continued with a boot -as. The options will request the kernel to ask for the root filesystem to mount (), and make the boot process stop in single-user mode (), where the root filesystem is mounted read-only. That way, even if only one plex of a multi-plex volume has been mounted, no data inconsistency between plexes is being risked. At the prompt asking for a root filesystem to mount, any device that contains a valid root filesystem can be entered. If /etc/fstab had been set up correctly, the default should be something like ufs:/dev/vinum/root. A typical alternate choice would be something like ufs:da0d which could be a hypothetical partition that contains the pre-Vinum root filesystem. Care should be taken if one of the alias "a" partitions are entered here that are actually reference to the subdisks of the Vinum root device, because in a mirrored setup, this would only mount one piece of a mirrored root device. If this filesystem is to be mounted read-write later on, it is necessary to remove the other plex(es) of the Vinum root volume since these plexes would otherwise carry inconsistent data. Only primary bootstrap loads If /boot/loader fails to load, but the primary bootstrap still loads (visible by a single dash in the left column of the screen right after the boot process starts), an attempt can be made to interrupt the primary bootstrap at this point, using the space key. This will make the bootstrap stop in stage two, see . An attempt can be made here to boot off an alternate partition, like the partition containing the previous root filesystem that has been moved away from "a" above. Nothing boots, the bootstrap panics This situation will happen if the bootstrap had been destroyed by the Vinum installation. Unfortunately, Vinum accidentally currently leaves only 4 KB at the beginning of its partition free before starting to write its Vinum header information. However, the stage one and two bootstraps plus the disklabel embedded between them currently require 8 KB. So if a Vinum partition was started at offset 0 within a slice or disk that was meant to be bootable, the Vinum setup will trash the bootstrap. Similarly, if the above situation has been recovered, for example by booting from a Fixit medium, and the bootstrap has been re-installed using disklabel -B as described in , the bootstrap will trash the Vinum header, and Vinum will no longer find its disk(s). Though no actual Vinum configuration data or data in Vinum volumes will be trashed by this, and it would be possible to recover all the data by entering exact the same Vinum configuration data again, the situation is hard to fix at all. It would be necessary to move the entire Vinum partition by at least 4 KB off, in order to have the Vinum header and the system bootstrap no longer collide. Differences for FreeBSD 4.x Under FreeBSD 4.x, some internal functions required to make Vinum automatically scan all disks are missing, and the code that figures out the internal ID of the root device is not smart enough to handle a name like /dev/vinum/root automatically. Therefore, things are a little different here. Vinum must explicitly be told which disks to scan, using a line like the following one in /boot/loader.conf: vinum.drives="/dev/da0 /dev/da1" It is important that all drives are mentioned that could possibly contain Vinum data. It does not harm if more drives are listed, nor is it necessary to add each slice and/or partition explicitly, since Vinum will scan all slices and partitions of the named drives for valid Vinum headers. Since the routines used to parse the name of the root filesystem, and derive the device ID (major/minor number) are only prepared to handle classical device names like /dev/ad0s1a, they cannot make any sense out of a root volume name like /dev/vinum/root. For that reason, Vinum itself needs to pre-setup the internal kernel parameter that holds the ID of the root device during its own initialization. This is requested by passing the name of the root volume in the loader variable vinum.root. The entry in /boot/loader.conf to accomplish this looks like: vinum.root="root" Now, when the kernel initialization tries to find out the root device to mount, it sees whether some kernel module has already pre-initialized the kernel parameter for it. If that is the case, and the device claiming the root device matches the major number of the driver as figured out from the name of the root device string being passed (that is, "vinum" in our case), it will use the pre-allocated device ID, instead of trying to figure out one itself. That way, during the usual automatic startup, it can continue to mount the Vinum root volume for the root filesystem. However, when boot -a has been requesting to ask for entering the name of the root device manually, it must be noted that this routine still cannot actually parse a name entered there that refers to a Vinum volume. If any device name is entered that does not refer to a Vinum device, the mismatch between the major numbers of the pre-allocated root parameter and the driver as figured out from the given name will make this routine enter its normal parser, so entering a string like ufs:da0d will work as expected. Note that if this fails, it is however no longer possible to re-enter a string like ufs:vinum/root again, since it cannot be parsed. The only way out is to reboot again, and start over then. (At the askroot prompt, the initial /dev/ can always be omitted.)