diff --git a/en_US.ISO8859-1/books/handbook/config/chapter.sgml b/en_US.ISO8859-1/books/handbook/config/chapter.sgml index 942146e4b7..97265cf92a 100644 --- a/en_US.ISO8859-1/books/handbook/config/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/config/chapter.sgml @@ -1,1229 +1,1229 @@ Chern Lee Written by Mike Smith Based on a tutorial written by Matt Dillon Also based on tuning(7) written by Configuration and Tuning Synopsis system configuration/optimization Configuring a system correctly can substantially reduce the amount of work involved in maintaining and upgrading it in the future. This chapter describes some of the aspects of administrative configuration of FreeBSD systems. This chapter will also describe some of the parameters that can be set to tune a FreeBSD system for optimum performance. After reading this chapter, you will know: Why and how to efficiently size, layout, and place filesystems and swap partitions on your hard drive. The basics of the rc.conf configuration and /usr/local/etc/rc.d startup systems. How to configure virtual hosts on your network devices. How to use the various configuration files in /etc. How to tune FreeBSD using sysctl variables. How to tune disk performance and modify kernel limitations. Before reading this chapter, you should: Understand the basics of Unix and FreeBSD (). Be familiar with keeping FreeBSD sources up to date (), and the basics of kernel configuration/compilation (). Initial Configuration Partition Layout Partition layout /etc /var /usr Base Partitions When laying out your filesystem with &man.disklabel.8; or &man.sysinstall.8;, it is important to remember that hard drives can transfer data at a faster rate from the outer tracks than the inner. Knowing this, you should place your smaller, heavily-accessed filesystems, such as root and swap, closer to the outside of the drive, while placing larger partitions, such as /usr, towards the inner. To do so, it is a good idea to create partitions in a similar order: root, swap, /var, /usr. The size of your /var partition reflects the intended use of your machine. /var is primarily used to hold mailboxes, log files, and printer spools. Mailboxes and log files, in particular, can grow to unexpected sizes based upon how many users are on your system and how long your log files are kept. If you intend to run a mail server, a /var partition of over a gigabyte can be suitable. Additionally, /var/tmp must be large enough to contain any packages you may wish to add. The /usr partition holds the bulk of the files required to support the system and a subdirectory within it called /usr/local holds the bulk of the files installed from the &man.ports.7; hierarchy. If you do not use ports all that much and do not intend to keep system source (/usr/src) on the machine, you - can get away with a 1 gigabyte /usr + can get away with a 1 gigabyte /usr partition. However, if you install a lot of ports (especially window managers and Linux binaries), we recommend at least a two gigabyte /usr and if you also intend to keep system source on the machine, we recommend a three gigabyte /usr. Do not underestimate the amount of space you will need in this partition, it can creep up and surprise you! When sizing your partitions, keep in mind the space requirements for your system to grow. Running out of space in one partition while having plenty in another can lead to much frustration. Some users who have used &man.sysinstall.8;'s Auto-defaults partition sizer have found either their root or /var partitions too small later on. Partition wisely and generously. Swap Partition swap sizing swap partition As a rule of thumb, your swap space should typically be double the amount of main memory. For example, if the machine - has 128 megabytes of memory, the swap file should be 256 - megabytes. Systems with lesser memory may perform better with + has 128 megabytes of memory, the swap file should be + 256 megabytes. Systems with lesser memory may perform better with a lot more swap. It is not recommended that you configure any - less than 256 megabytes of swap on a system and you should + less than 256 megabytes of swap on a system and you should keep in mind future memory expansion when sizing the swap partition. The kernel's VM paging algorithms are tuned to perform best when the swap partition is at least two times the size of main memory. Configuring too little swap can lead to inefficiencies in the VM page scanning code as well as create issues later on if you add more memory to your machine. Finally, on larger systems with multiple SCSI disks (or multiple IDE disks operating on different controllers), it is strongly recommend that you configure swap on each drive (up to four drives). The swap partitions on the drives should be approximately the same size. The kernel can handle arbitrary sizes but internal data structures scale to 4 times the largest swap partition. Keeping the swap partitions near the same size will allow the kernel to optimally stripe swap space across the disks. Do not worry about overdoing it a little, swap space is the saving grace of Unix. Even if you do not normally use much swap, it can give you more time to recover from a runaway program before being forced to reboot. Why Partition? Why partition at all? Why not create one big root partition and be done with it? Then I do not have to worry about undersizing things! There are several reasons this is not a good idea. First, each partition has different operational characteristics and separating them allows the filesystem to tune itself to those characteristics. For example, the root and /usr partitions are read-mostly, with very little writing, while a lot of reading and writing could occur in /var and /var/tmp. By properly partitioning your system, fragmentation introduced in the smaller more heavily write-loaded partitions will not bleed over into the mostly-read partitions. Additionally, keeping the write-loaded partitions closer to the edge of the disk, for example before the really big partition instead of after in the partition table, will increase I/O performance in the partitions where you need it the most. Now it is true that you might also need I/O performance in the larger partitions, but they are so large that shifting them more towards the edge of the disk will not lead to a significant performance improvement whereas moving /var to the edge can have a huge impact. Finally, there are safety concerns. Having a small, neat root partition that is essentially read-only gives it a greater chance of surviving a bad crash intact. Core Configuration rc files rc.conf The principal location for system configuration information is within /etc/rc.conf. This file contains a wide range of configuration information, principally used at system startup to configure the system. Its name directly implies this; it is configuration information for the rc* files. An administrator should make entries in the rc.conf file to override the default settings from /etc/defaults/rc.conf. The defaults file should not be copied verbatim to /etc - it contains default values, not examples. All system-specific changes should be made in the rc.conf file itself. A number of strategies may be applied in clustered applications to separate site-wide configuration from system-specific configuration in order to keep administration overhead down. The recommended approach is to place site-wide configuration into another file, such as /etc/rc.conf.site, and then include this file into /etc/rc.conf, which will contain only system-specific information. As rc.conf is read by &man.sh.1; it is trivial to achieve this. For example: rc.conf: . rc.conf.site hostname="node15.example.com" network_interfaces="fxp0 lo0" ifconfig_fxp0="inet 10.1.1.1" rc.conf.site: defaultrouter="10.1.1.254" saver="daemon" blanktime="100" The rc.conf.site file can then be distributed to every system using rsync or a similar program, while the rc.conf file remains unique. Upgrading the system using &man.sysinstall.8; or make world will not overwrite the rc.conf file, so system configuration information will not be lost. Application Configuration Typically, installed applications have their own configuration files, with their own syntax, etc. It is important that these files be kept separate from the base system, so that they may be easily located and managed by the package management tools. /usr/local/etc Typically, these files are installed in /usr/local/etc. In the case where an application has a large number of configuration files, a subdirectory will be created to hold them. Normally, when a port or package is installed, sample configuration files are also installed. These are usually identified with a .default suffix. If there are no existing configuration files for the application, they will be created by copying the .default files. For example, consider the contents of the directory /usr/local/etc/apache: -rw-r--r-- 1 root wheel 2184 May 20 1998 access.conf -rw-r--r-- 1 root wheel 2184 May 20 1998 access.conf.default -rw-r--r-- 1 root wheel 9555 May 20 1998 httpd.conf -rw-r--r-- 1 root wheel 9555 May 20 1998 httpd.conf.default -rw-r--r-- 1 root wheel 12205 May 20 1998 magic -rw-r--r-- 1 root wheel 12205 May 20 1998 magic.default -rw-r--r-- 1 root wheel 2700 May 20 1998 mime.types -rw-r--r-- 1 root wheel 2700 May 20 1998 mime.types.default -rw-r--r-- 1 root wheel 7980 May 20 1998 srm.conf -rw-r--r-- 1 root wheel 7933 May 20 1998 srm.conf.default The filesize difference shows that only the srm.conf file has been changed. A later update of the Apache port would not overwrite this changed file. Starting Services services It is common for a system to host a number of services. These may be started in several different fashions, each having different advantages. /usr/local/etc/rc.d Software installed from a port or the packages collection will often place a script in /usr/local/etc/rc.d which is invoked at system startup with a argument, and at system shutdown with a argument. This is the recommended way for starting system-wide services that are to be run as root, or that expect to be started as root. These scripts are registered as part of the installation of the package, and will be removed when the package is removed. A generic startup script in /usr/local/etc/rc.d looks like: #!/bin/sh echo -n ' FooBar' case "$1" in start) /usr/local/bin/foobar ;; stop) kill -9 `cat /var/run/foobar.pid` ;; *) echo "Usage: `basename $0` {start|stop}" >&2 exit 64 ;; esac exit 0 The startup scripts of FreeBSD will look in /usr/local/etc/rc.d for scripts that have an .sh extension and are executable by root. Those scripts that are found are called with an option at startup, and at shutdown to allow them to carry out their purpose. So if you wanted the above sample script to be picked up and run at the proper time during system startup, you should save it to a file called FooBar.sh in /usr/local/etc/rc.d and make sure it's executable. You can make a shell script executable with &man.chmod.1; as shown below: &prompt.root; chmod 755 FooBar.sh Some services expect to be invoked by &man.inetd.8; when a connection is received on a suitable port. This is common for mail reader servers (POP and IMAP, etc.). These services are enabled by editing the file /etc/inetd.conf. See &man.inetd.8; for details on editing this file. Some additional system services may not be covered by the toggles in /etc/rc.conf. These are traditionally enabled by placing the command(s) to invoke them - in /etc/rc.local. As of FreeBSD 3.1 there + in /etc/rc.local. As of FreeBSD 3.1 there is no default /etc/rc.local; if it is created by the administrator it will however be honored in the normal fashion. Note that rc.local is generally regarded as the location of last resort; if there is a better place to start a service, do it there. Do not place any commands in /etc/rc.conf. To start daemons, or run any commands at boot time, place a script in /usr/local/etc/rc.d instead. It is also possible to use the &man.cron.8; daemon to start system services. This approach has a number of advantages, not least being that because &man.cron.8; runs these processes as the owner of the crontab, services may be started and maintained by non-root users. This takes advantage of a feature of &man.cron.8;: the time specification may be replaced by @reboot, which will cause the job to be run when &man.cron.8; is started shortly after system boot. Virtual Hosts virtual hosts ip aliases A very common use of FreeBSD is virtual site hosting, where one server appears to the network as many servers. This is achieved by assigning multiple network addresses to a single interface. A given network interface has one real address, and may have any number of alias addresses. These aliases are normally added by placing alias entries in /etc/rc.conf. An alias entry for the interface fxp0 looks like: ifconfig_fxp0_alias0="inet xxx.xxx.xxx.xxx netmask xxx.xxx.xxx.xxx" Note that alias entries must start with alias0 and proceed upwards in order, (for example, _alias1, _alias2, and so on). The configuration process will stop at the first missing number. The calculation of alias netmasks is important, but fortunately quite simple. For a given interface, there must be one address which correctly represents the network's netmask. Any other addresses which fall within this network must have a netmask of all 1's. For example, consider the case where the fxp0 interface is connected to two networks, the 10.1.1.0 network with a netmask of 255.255.255.0 and the 202.0.75.16 network with a netmask of 255.255.255.240. We want the system to appear at 10.1.1.1 through 10.1.1.5 and at 202.0.75.17 through 202.0.75.20. The following entries configure the adapter correctly for this arrangement: ifconfig_fxp0="inet 10.1.1.1 netmask 255.255.255.0" ifconfig_fxp0_alias0="inet 10.1.1.2 netmask 255.255.255.255" ifconfig_fxp0_alias1="inet 10.1.1.3 netmask 255.255.255.255" ifconfig_fxp0_alias2="inet 10.1.1.4 netmask 255.255.255.255" ifconfig_fxp0_alias3="inet 10.1.1.5 netmask 255.255.255.255" ifconfig_fxp0_alias4="inet 202.0.75.17 netmask 255.255.255.240" ifconfig_fxp0_alias5="inet 202.0.75.18 netmask 255.255.255.255" ifconfig_fxp0_alias6="inet 202.0.75.19 netmask 255.255.255.255" ifconfig_fxp0_alias7="inet 202.0.75.20 netmask 255.255.255.255" Configuration Files <filename>/etc</filename> Layout There are a number of directories in which configuration information is kept. These include: /etc Generic system configuration information; data here is system-specific. /etc/defaults Default versions of system configuration files. /etc/mail Extra &man.sendmail.8; configuration, other MTA configuration files. /etc/ppp Configuration for both user- and kernel-ppp programs. /etc/namedb Default location for &man.named.8; data. Normally named.conf and zone files are stored here. /usr/local/etc Configuration files for installed applications. May contain per-application subdirectories. /usr/local/etc/rc.d Start/stop scripts for installed applications. /var/db Automatically generated system-specific database files, such as the package database, the locate database, and so on Hostnames hostname DNS <filename>/etc/resolv.conf</filename> resolv.conf /etc/resolv.conf dictates how FreeBSD's resolver accesses the Internet Domain Name System (DNS). The most common entries to resolv.conf are: nameserver The IP address of a name server the resolver should query. The servers are queried in the order listed with a maximum of three. search Search list for hostname lookup. This is normally determined by the domain of the local hostname. domain The local domain name. A typical resolv.conf: search example.com nameserver 147.11.1.11 nameserver 147.11.100.30 Only one of the search and domain options should be used. If you are using DHCP, &man.dhclient.8; usually rewrites resolv.conf with information received from the DHCP server. <filename>/etc/hosts</filename> hosts /etc/hosts is a simple text database reminiscent of the old Internet. It works in conjunction with DNS and NIS providing name to IP address mappings. Local computers connected via a LAN can be placed in here for simplistic naming purposes instead of setting up a &man.named.8; server. Additionally, /etc/hosts can be used to provide a local record of Internet names, reducing the need to query externally for commonly accessed names. # $FreeBSD$ # # Host Database # This file should contain the addresses and aliases # for local hosts that share this file. # In the presence of the domain name service or NIS, this file may # not be consulted at all; see /etc/nsswitch.conf for the resolution order. # # ::1 localhost localhost.my.domain myname.my.domain 127.0.0.1 localhost localhost.my.domain myname.my.domain # # Imaginary network. #10.0.0.2 myname.my.domain myname #10.0.0.3 myfriend.my.domain myfriend # # According to RFC 1918, you can use the following IP networks for # private nets which will never be connected to the Internet: # # 10.0.0.0 - 10.255.255.255 # 172.16.0.0 - 172.31.255.255 # 192.168.0.0 - 192.168.255.255 # # In case you want to be able to connect to the Internet, you need # real official assigned numbers. PLEASE PLEASE PLEASE do not try # to invent your own network numbers but instead get one from your # network provider (if any) or from the Internet Registry (ftp to # rs.internic.net, directory `/templates'). # /etc/hosts takes on the simple format of: [Internet address] [official hostname] [alias1] [alias2] ... For example: 10.0.0.1 myRealHostname.example.com myRealHostname foobar1 foobar2 Consult &man.hosts.5; for more information. Log File Configuration log files <filename>syslog.conf</filename> syslog.conf syslog.conf is the configuration file for the &man.syslogd.8; program. It indicates which types of syslog messages are logged to particular log files. # $FreeBSD$ # # Spaces ARE valid field separators in this file. However, # other *nix-like systems still insist on using tabs as field # separators. If you are sharing this file between systems, you # may want to use only tabs as field separators here. # Consult the syslog.conf(5) manual page. *.err;kern.debug;auth.notice;mail.crit /dev/console *.notice;kern.debug;lpr.info;mail.crit;news.err /var/log/messages security.* /var/log/security mail.info /var/log/maillog lpr.info /var/log/lpd-errs cron.* /var/log/cron *.err root *.notice;news.err root *.alert root *.emerg * # uncomment this to log all writes to /dev/console to /var/log/console.log #console.info /var/log/console.log # uncomment this to enable logging of all log messages to /var/log/all.log #*.* /var/log/all.log # uncomment this to enable logging to a remote log host named loghost #*.* @loghost # uncomment these if you're running inn # news.crit /var/log/news/news.crit # news.err /var/log/news/news.err # news.notice /var/log/news/news.notice !startslip *.* /var/log/slip.log !ppp *.* /var/log/ppp.log Consult the &man.syslog.conf.5; manual page for more information. <filename>newsyslog.conf</filename> newsyslog.conf newsyslog.conf is the configuration file for &man.newsyslog.8;, a program that is normally scheduled to run by &man.cron.8;. &man.newsyslog.8; determines when log files require archiving or rearranging. logfile is moved to logfile.0, logfile.0 is moved to logfile.1, and so on. Alternatively, the log files may be archived in &man.gzip.1; format causing them to be named: logfile.0.gz, logfile.1.gz, and so on. newsyslog.conf indicates which log files are to be managed, how many are to be kept, and when they are to be touched. Log files can be rearranged and/or archived when they have either reached a certain size, or at a certain periodic time/date. # configuration file for newsyslog # $FreeBSD$ # # filename [owner:group] mode count size when [ZB] [/pid_file] [sig_num] /var/log/cron 600 3 100 * Z /var/log/amd.log 644 7 100 * Z /var/log/kerberos.log 644 7 100 * Z /var/log/lpd-errs 644 7 100 * Z /var/log/maillog 644 7 * @T00 Z /var/log/sendmail.st 644 10 * 168 B /var/log/messages 644 5 100 * Z /var/log/all.log 600 7 * @T00 Z /var/log/slip.log 600 3 100 * Z /var/log/ppp.log 600 3 100 * Z /var/log/security 600 10 100 * Z /var/log/wtmp 644 3 * @01T05 B /var/log/daily.log 640 7 * @T00 Z /var/log/weekly.log 640 5 1 $W6D0 Z /var/log/monthly.log 640 12 * $M1D0 Z /var/log/console.log 640 5 100 * Z Consult the &man.newsyslog.8; manual page for more information. <filename>sysctl.conf</filename> sysctl.conf sysctl sysctl.conf looks much like rc.conf. Values are set in a variable=value form. The specified values are set after the system goes into multi-user mode. Not all variables are settable in this mode. A sample sysctl.conf turning off logging of fatal signal exits and letting Linux programs know they are really running under FreeBSD: kern.logsigexit=0 # Do not log fatal signal exits (e.g. sig 11) compat.linux.osname=FreeBSD compat.linux.osrelease=4.3-STABLE Tuning with sysctl sysctl Tuning with sysctl &man.sysctl.8; is an interface that allows you to make changes to a running FreeBSD system. This includes many advanced options of the TCP/IP stack and virtual memory system that can dramatically improve performance for an experienced system administrator. Over five hundred system variables can be read and set using &man.sysctl.8;. At its core, &man.sysctl.8; serves two functions: to read and to modify system settings. To view all readable variables: &prompt.user; sysctl -a To read a particular variable, for example, kern.maxproc: &prompt.user; sysctl kern.maxproc kern.maxproc: 1044 To set a particular variable, use the intuitive variable=value syntax: &prompt.root; sysctl kern.maxfiles=5000 kern.maxfiles: 2088 -> 5000 Settings of sysctl variables are usually either strings, numbers, or booleans (a boolean being 1 for yes or a 0 for no). Tuning Disks Sysctl Variables <varname>vfs.vmiodirenable</varname> vfs.vmiodirenable The vfs.vmiodirenable sysctl variable may be set to either 0 (off) or 1 (on); it is 1 by default. This variable controls how directories are cached by the system. Most directories are - small, using just a single fragment (typically 1K) in the - filesystem and less (typically 512 bytes) in the buffer + small, using just a single fragment (typically 1 K) in the + filesystem and less (typically 512 bytes) in the buffer cache. However, when operating in the default mode the buffer cache will only cache a fixed number of directories even if you have a huge amount of memory. Turning on this sysctl allows the buffer cache to use the VM Page Cache to cache the directories, making all the memory available for caching directories. However, the minimum in-core memory used to cache a directory is the - physical page size (typically 4K) rather than 512 bytes. We + physical page size (typically 4 K) rather than 512 bytes. We recommend turning this option on if you are running any services which manipulate large numbers of files. Such services can include web caches, large mail systems, and news systems. Turning on this option will generally not reduce performance even with the wasted memory but you should experiment to find out. <varname>hw.ata.wc</varname> hw.ata.wc - FreeBSD 4.3 flirted with turning off IDE write caching. + FreeBSD 4.3 flirted with turning off IDE write caching. This reduced write bandwidth to IDE disks but was considered necessary due to serious data consistency issues introduced by hard drive vendors. The problem is that IDE drives lie about when a write completes. With IDE write caching turned on, IDE hard drives not only write data to disk out of order, but will sometimes delay writing some blocks indefinitely when under heavy disk loads. A crash or power failure may cause serious filesystem corruption. FreeBSD's default was changed to be safe. Unfortunately, the result was such a huge performance loss that we changed write caching back to on by default after the release. You should check the default on your system by observing the hw.ata.wc sysctl variable. If IDE write caching is turned off, you can turn it back on by setting the kernel variable back to 1. This must be done from the boot loader at boot time. Attempting to do it after the kernel boots will have no effect. For more information, please see &man.ata.4;. Soft Updates Soft Updates tunefs The &man.tunefs.8; program can be used to fine-tune a filesystem. This program has many different options, but for now we are only concerned with toggling Soft Updates on and off, which is done by: &prompt.root; tunefs -n enable /filesystem &prompt.root; tunefs -n disable /filesystem A filesystem cannot be modified with &man.tunefs.8; while it is mounted. A good time to enable Soft Updates is before any partitions have been mounted, in single-user mode. - As of FreeBSD 4.5, it is possible to enable Soft Updates + As of FreeBSD 4.5, it is possible to enable Soft Updates at filesystem creation time, through use of the -U option to &man.newfs.8;. Soft Updates drastically improves meta-data performance, mainly file creation and deletion, through the use of a memory cache. We recommend to use Soft Updates on all of your filesystems. There are two downsides to Soft Updates that you should be aware of: First, Soft Updates guarantees filesystem consistency in the case of a crash but could very easily be several seconds (even a minute!) behind updating the physical disk. If your system crashes you may lose more work than otherwise. Secondly, Soft Updates delays the freeing of filesystem blocks. If you have a filesystem (such as the root filesystem) which is almost full, performing a major update, such as make installworld, can cause the filesystem to run out of space and the update to fail. More details about Soft Updates Soft Updates (Details) There are two traditional approaches to writing a filesystem's meta-data back to disk. (Meta-data updates are updates to non-content data like inodes or directories.) Historically, the default behavior was to write out meta-data updates synchronously. If a directory had been changed, the system waited until the change was actually written to disk. The file data buffers (file contents) were passed through the buffer cache and backed up to disk later on asynchronously. The advantage of this implementation is that it operates safely. If there is a failure during an update, the meta-data are always in a consistent state. A file is either created completely or not at all. If the data blocks of a file did not find their way out of the buffer cache onto the disk by the time of the crash, &man.fsck.8; is able to recognize this and repair the filesystem by setting the file length to 0. Additionally, the implementation is clear and simple. The disadvantage is that meta-data changes are slow. An rm -r, for instance, touches all the files in a directory sequentially, but each directory change (deletion of a file) will be written synchronously to the disk. This includes updates to the directory itself, to the inode table, and possibly to indirect blocks allocated by the file. Similar considerations apply for unrolling large hierarchies (tar -x). The second case is asynchronous meta-data updates. This is the default for Linux/ext2fs and mount -o async for *BSD ufs. All meta-data updates are simply being passed through the buffer cache too, that is, they will be intermixed with the updates of the file content data. The advantage of this implementation is there is no need to wait until each meta-data update has been written to disk, so all operations which cause huge amounts of meta-data updates work much faster than in the synchronous case. Also, the implementation is still clear and simple, so there is a low risk for bugs creeping into the code. The disadvantage is that there is no guarantee at all for a consistent state of the filesystem. If there is a failure during an operation that updated large amounts of meta-data (like a power failure, or someone pressing the reset button), the filesystem will be left in an unpredictable state. There is no opportunity to examine the state of the filesystem when the system comes up again; the data blocks of a file could already have been written to the disk while the updates of the inode table or the associated directory were not. It is actually impossible to implement a fsck which is able to clean up the resulting chaos (because the necessary information is not available on the disk). If the filesystem has been damaged beyond repair, the only choice is to newfs it and restore it from backup. The usual solution for this problem was to implement dirty region logging, which is also referred to as journaling, although that term is not used consistently and is occasionally applied to other forms of transaction logging as well. Meta-data updates are still written synchronously, but only into a small region of the disk. Later on they will be moved to their proper location. Because the logging area is a small, contiguous region on the disk, there are no long distances for the disk heads to move, even during heavy operations, so these operations are quicker than synchronous updates. Additionally the complexity of the implementation is fairly limited, so the risk of bugs being present is low. A disadvantage is that all meta-data are written twice (once into the logging region and once to the proper location) so for normal work, a performance pessimization might result. On the other hand, in case of a crash, all pending meta-data operations can be quickly either rolled-back or completed from the logging area after the system comes up again, resulting in a fast filesystem startup. Kirk McKusick, the developer of Berkeley FFS, solved this problem with Soft Updates: all pending meta-data updates are kept in memory and written out to disk in a sorted sequence (ordered meta-data updates). This has the effect that, in case of heavy meta-data operations, later updates to an item catch the earlier ones if the earlier ones are still in memory and have not already been written to disk. So all operations on, say, a directory are generally performed in memory before the update is written to disk (the data blocks are sorted according to their position so that they will not be on the disk ahead of their meta-data). If the system crashes, this causes an implicit log rewind: all operations which did not find their way to the disk appear as if they had never happened. A consistent filesystem state is maintained that appears to be the one of 30 to 60 seconds earlier. The algorithm used guarantees that all resources in use are marked as such in their appropriate bitmaps: blocks and inodes. After a crash, the only resource allocation error that occurs is that resources are marked as used which are actually free. &man.fsck.8; recognizes this situation, and frees the resources that are no longer used. It is safe to ignore the dirty state of the filesystem after a crash by forcibly mounting it with mount -f. In order to free resources that may be unused, &man.fsck.8; needs to be run at a later time. This is the idea behind the background fsck: at system startup time, only a snapshot of the filesystem is recorded. The fsck can be run later on. All filesystems can then be mounted dirty, so the system startup proceeds in multiuser mode. Then, background fscks will be scheduled for all filesystems where this is required, to free resources that may be unused. (Filesystems that do not use Soft Updates still need the usual foreground fsck though.) The advantage is that meta-data operations are nearly as fast as asynchronous updates (i.e. faster than with logging, which has to write the meta-data twice). The disadvantages are the complexity of the code (implying a higher risk for bugs in an area that is highly sensitive regarding loss of user data), and a higher memory consumption. Additionally there are some idiosyncrasies one has to get used to. After a crash, the state of the filesystem appears to be somewhat older. In situations where the standard synchronous approach would have caused some zero-length files to remain after the fsck, these files do not exist at all with a Soft Updates filesystem because neither the meta-data nor the file contents have ever been written to disk. Disk space is not released until the updates have been written to disk, which may take place some time after running rm. This may cause problems when installing large amounts of data on a filesystem that does not have enough free space to hold all the files twice. Tuning Kernel Limits Tuning kernel limits File/Process Limits <varname>kern.maxfiles</varname> kern.maxfiles kern.maxfiles can be raised or lowered based upon your system requirements. This variable indicates the maximum number of file descriptors on your system. When the file descriptor table is full, file: table is full will show up repeatedly in the system message buffer, which can be viewed with the dmesg command. Each open file, socket, or fifo uses one file descriptor. A large-scale production server may easily require many thousands of file descriptors, depending on the kind and number of services running concurrently. kern.maxfile's default value is dictated by the option in your kernel configuration file. kern.maxfiles grows proportionally to the value of . When compiling a custom kernel, it is a good idea to set this kernel configuration option according to the uses of your system. From this number, the kernel is given most of its pre-defined limits. Even though a production machine may not actually have 256 users connected as once, the resources needed may be similar to a high-scale web server. - As of FreeBSD 4.5, setting to + As of FreeBSD 4.5, setting to 0 in your kernel configuration file will choose a reasonable default value based on the amount of RAM present in your system. Network Limits The kernel configuration option dictates the amount of network mbufs available to the system. A heavily-trafficked server with a low number of MBUFs will hinder FreeBSD's ability. Each cluster represents - approximately 2K of memory, so a value of 1024 represents 2 + approximately 2 K of memory, so a value of 1024 represents 2 megabytes of kernel memory reserved for network buffers. A simple calculation can be done to figure out how many are needed. If you have a web server which maxes out at 1000 - simultaneous connections, and each connection eats a 16K receive - and 16K send buffer, you need approximately 32MB worth of + simultaneous connections, and each connection eats a 16 K receive + and 16 K send buffer, you need approximately 32 MB worth of network buffers to cover the web server. A good rule of thumb is - to multiply by 2, so 2x32 MB / 2 KB = 64 MB / 2 kB = 32768. + to multiply by 2, so 2x32 MB / 2 KB = 64 MB / 2 kB = 32768. Adding Swap Space No matter how well you plan, sometimes a system doesn't run as you expect. If you find you need more swap space, it's simple enough to add. You have three ways to increase swap space: adding a new hard drive, enabling swap over NFS, and creating a swap file on an existing partition. Swap on a New Hard Drive The best way to add swap, of course, is to use this as an excuse to add another hard drive. You can always use another hard drive, after all. If you can do this, go reread the discussion of swap space from the Initial Configuration section of the Handbook for some suggestions on how to best arrange your swap. Swapping over NFS Swapping over NFS is only recommended if you do not have a local hard disk to swap to. Swapping over NFS is slow and inefficient in versions of FreeBSD prior to 4.X. It is reasonably fast and efficient in 4.0-RELEASE and newer. Even with newer versions of FreeBSD, NFS swapping will be limited by the available network bandwidth and puts an additional burden on the NFS server. Swapfiles You can create a file of a specified size to use as a swap file. In our example here we will use a 64MB file called /usr/swap0. You can use any name you want, of course. Creating a Swapfile Be certain that your kernel configuration includes the vnode driver. It is not in recent versions of GENERIC. pseudo-device vn 1 #Vnode driver (turns a file into a device) create a vn-device: &prompt.root; cd /dev &prompt.root; sh MAKEDEV vn0 create a swapfile (/usr/swap0): &prompt.root; dd if=/dev/zero of=/usr/swap0 bs=1024k count=64 set proper permissions on (/usr/swap0): &prompt.root; chmod 0600 /usr/swap0 enable the swap file in /etc/rc.conf: swapfile="/usr/swap0" # Set to name of swapfile if aux swapfile desired. Reboot the machine or to enable the swap file immediately, type: &prompt.root; vnconfig -e /dev/vn0b /usr/swap0 swap diff --git a/en_US.ISO8859-1/books/handbook/introduction/chapter.sgml b/en_US.ISO8859-1/books/handbook/introduction/chapter.sgml index 9c83ea994b..a7b07c2eef 100644 --- a/en_US.ISO8859-1/books/handbook/introduction/chapter.sgml +++ b/en_US.ISO8859-1/books/handbook/introduction/chapter.sgml @@ -1,905 +1,905 @@ Jim Mock Restructured, reorganized, and parts rewritten by Introduction Synopsis Thank you for your interest in FreeBSD! The following chapter covers various items about the FreeBSD Project, such as its history, goals, development model, and so on. After reading this chapter, you will know: How FreeBSD relates to other computer operating systems. The history of the FreeBSD Project. The goals of the FreeBSD Project. The basics of the FreeBSD open-source development model. And of course: where the name FreeBSD comes from. Welcome to FreeBSD! 4.4BSD-Lite FreeBSD is a 4.4BSD-Lite based operating system for the Intel architecture (x86) and DEC Alpha based systems. Ports to other architectures are also underway. For a brief overview of FreeBSD, see the next section. You can also read about the history of FreeBSD, or the current release. If you are interested in contributing something to the Project (code, hardware, unmarked bills), see the Contributing to FreeBSD article. What Can FreeBSD Do? FreeBSD has many noteworthy features. Some of these are: preemptive multitasking Preemptive multitasking with dynamic priority adjustment to ensure smooth and fair sharing of the computer between applications and users, even under the heaviest of loads. multi-user facilities Multi-user facilities which allow many people to use a FreeBSD system simultaneously for a variety of things. This means, for example, that system peripherals such as printers and tape drives are properly shared between all users on the system or the network and that individual resource limits can be placed on users or groups of users, protecting critical system resources from over-use. TCP/IP networking Strong TCP/IP networking with support for industry standards such as SLIP, PPP, NFS, DHCP, and NIS. This means that your FreeBSD machine can interoperate easily with other systems as well as act as an enterprise server, providing vital functions such as NFS (remote file access) and email services or putting your organization on the Internet with WWW, FTP, routing and firewall (security) services. memory protection Memory protection ensures that applications (or users) cannot interfere with each other. One application crashing will not affect others in any way. FreeBSD is a 32-bit operating system (64-bit on the Alpha) and was designed as such from the ground up. X Window System XFree86 The industry standard X Window System (X11R6) provides a graphical user interface (GUI) for the cost of a common VGA card and monitor and comes with full sources. binary compatibility Linux binary compatibility SCO binary compatibility SVR4 binary compatibility BSD/OS binary compatibility NetBSD Binary compatibility with many programs built for Linux, SCO, SVR4, BSDI and NetBSD. Thousands of ready-to-run applications are available from the FreeBSD ports and packages collection. Why search the net when you can find it all right here? Thousands of additional and easy-to-port applications are available on the Internet. FreeBSD is source code compatible with most popular commercial Unix systems and thus most applications require few, if any, changes to compile. virtual memory Demand paged virtual memory and merged VM/buffer cache design efficiently satisfies applications with large appetites for memory while still maintaining interactive response to other users. Symetric Multi-Processing (SMP) SMP support for machines with multiple CPUs. compilers C compilers C++ compilers Fortran A full complement of C, C++, Fortran, and Perl development tools. Many additional languages for advanced research and development are also available in the ports and packages collection. source code Source code for the entire system means you have the greatest degree of control over your environment. Why be locked into a proprietary solution at the mercy of your vendor when you can have a truly open system? Extensive online documentation. And many more! 4.4BSD-Lite Computer Systems Research Group (CSRG) U.C. Berkeley FreeBSD is based on the 4.4BSD-Lite release from Computer Systems Research Group (CSRG) at the University of California at Berkeley, and carries on the distinguished tradition of BSD systems development. In addition to the fine work provided by CSRG, the FreeBSD Project has put in many thousands of hours in fine tuning the system for maximum performance and reliability in real-life load situations. As many of the commercial giants struggle to field PC operating systems with such features, performance and reliability, FreeBSD can offer them now! The applications to which FreeBSD can be put are truly limited only by your own imagination. From software development to factory automation, inventory control to azimuth correction of remote satellite antennae; if it can be done with a commercial Unix product then it is more than likely that you can do it with FreeBSD too! FreeBSD also benefits significantly from the literally thousands of high quality applications developed by research centers and universities around the world, often available at little to no cost. Commercial applications are also available and appearing in greater numbers every day. Because the source code for FreeBSD itself is generally available, the system can also be customized to an almost unheard of degree for special applications or projects, and in ways not generally possible with operating systems from most major commercial vendors. Here is just a sampling of some of the applications in which people are currently using FreeBSD: Internet Services: The robust TCP/IP networking built into FreeBSD makes it an ideal platform for a variety of Internet services such as: FTP servers FTP servers web servers World Wide Web servers (standard or secure [SSL]) firewall IP masquerading Firewalls and NAT (IP masquerading) gateways electronic mail Electronic Mail servers USENET USENET News or Bulletin Board Systems And more... With FreeBSD, you can easily start out small with an inexpensive 386 class PC and upgrade all the way up to a quad-processor Xeon with RAID storage as your enterprise grows. Education: Are you a student of computer science or a related engineering field? There is no better way of learning about operating systems, computer architecture and networking than the hands on, under the hood experience that FreeBSD can provide. A number of freely available CAD, mathematical and graphic design packages also make it highly useful to those whose primary interest in a computer is to get other work done! Research: With source code for the entire system available, FreeBSD is an excellent platform for research in operating systems as well as other branches of computer science. FreeBSD's freely available nature also makes it possible for remote groups to collaborate on ideas or shared development without having to worry about special licensing agreements or limitations on what may be discussed in open forums. router DNS Server Networking: Need a new router? A name server (DNS)? A firewall to keep people out of your internal network? FreeBSD can easily turn that unused 386 or 486 PC sitting in the corner into an advanced router with sophisticated packet-filtering capabilities. X Window System XFree86 X Window System Accellerated-X X Window workstation: FreeBSD is a fine choice for an inexpensive X terminal solution, either using the freely available XFree86 server or one of the excellent commercial servers provided by X Inside. Unlike an X terminal, FreeBSD allows many applications to be run locally, if desired, thus relieving the burden on a central server. FreeBSD can even boot diskless, making individual workstations even cheaper and easier to administer. GNU Compiler Collection Software Development: The basic FreeBSD system comes with a full complement of development tools including the renowned GNU C/C++ compiler and debugger. FreeBSD is available in both source and binary form on CDROM and via anonymous FTP. Please see for more information about obtaining FreeBSD. Who uses FreeBSD? Users Large sites running FreeBSD FreeBSD is used to power some of the biggest sites on the Internet, including: Yahoo! Yahoo! Apache Apache Be, Inc. Be, Inc. Blue Mountain Arts Blue Mountain Arts Pair Networks Pair Networks Whistle Communications Whistle Communications Microsoft Microsoft Hotmail Hotmail Sony Japan Sony Japan and many more. About the FreeBSD Project The following section provides some background information on the project, including a brief history, project goals, and the development model of the project. Jordan Hubbard Contributed by A Brief History of FreeBSD 386BSD Patchkit Hubbard, Jordan Williams, Nate Grimes, Rod FreeBSD Project History The FreeBSD project had its genesis in the early part of 1993, partially as an outgrowth of the Unofficial 386BSD Patchkit by the patchkit's last 3 coordinators: Nate Williams, Rod Grimes and myself. 386BSD Our original goal was to produce an intermediate snapshot of 386BSD in order to fix a number of problems with it that the patchkit mechanism just was not capable of solving. Some of you may remember the early working title for the project being 386BSD 0.5 or 386BSD Interim in reference to that fact. Jolitz, Bill 386BSD was Bill Jolitz's operating system, which had been up to that point suffering rather severely from almost a year's worth of neglect. As the patchkit swelled ever more uncomfortably with each passing day, we were in unanimous agreement that something had to be done and decided to assist Bill by providing this interim cleanup snapshot. Those plans came to a rude halt when Bill Jolitz suddenly decided to withdraw his sanction from the project without any clear indication of what would be done instead. Greenman, David Walnut Creek CDROM It did not take us long to decide that the goal remained worthwhile, even without Bill's support, and so we adopted the name FreeBSD, coined by David Greenman. Our initial objectives were set after consulting with the system's current users and, once it became clear that the project was on the road to perhaps even becoming a reality, I contacted Walnut Creek CDROM with an eye towards improving FreeBSD's distribution channels for those many unfortunates without easy access to the Internet. Walnut Creek CDROM not only supported the idea of distributing FreeBSD on CD but also went so far as to provide the project with a machine to work on and a fast Internet connection. Without Walnut Creek CDROM's almost unprecedented degree of faith in what was, at the time, a completely unknown project, it is quite unlikely that FreeBSD would have gotten as far, as fast, as it has today. 4.3BSD-Lite Net/2 U.C. Berkeley 386BSD Free Software Foundation The first CDROM (and general net-wide) distribution was - FreeBSD 1.0, released in December of 1993. This was based on the + FreeBSD 1.0, released in December of 1993. This was based on the 4.3BSD-Lite (Net/2) tape from U.C. Berkeley, with many components also provided by 386BSD and the Free Software Foundation. It was a fairly reasonable success for a first offering, and we followed it with the highly successful FreeBSD 1.1 release in May of 1994. Novell U.C. Berkeley Net/2 AT&amp;T Around this time, some rather unexpected storm clouds formed on the horizon as Novell and U.C. Berkeley settled their long-running lawsuit over the legal status of the Berkeley Net/2 tape. A condition of that settlement was U.C. Berkeley's concession that large parts of Net/2 were encumbered code and the property of Novell, who had in turn acquired it from AT&T some time previously. What Berkeley got in return was Novell's blessing that the 4.4BSD-Lite release, when it was finally released, would be declared unencumbered and all existing Net/2 users would be strongly encouraged to switch. This included FreeBSD, and the project was given until the end of July 1994 to stop shipping its own Net/2 based product. Under the terms of that agreement, the project was allowed one last release - before the deadline, that release being FreeBSD 1.1.5.1. + before the deadline, that release being FreeBSD 1.1.5.1. FreeBSD then set about the arduous task of literally re-inventing itself from a completely new and rather incomplete set of 4.4BSD-Lite bits. The Lite releases were light in part because Berkeley's CSRG had removed large chunks of code required for actually constructing a bootable running system (due to various legal requirements) and the fact that the Intel port of 4.4 was highly incomplete. It took the project until November of 1994 to make this transition, at which point it - released FreeBSD 2.0 to the net and on CDROM (in late December). + released FreeBSD 2.0 to the net and on CDROM (in late December). Despite being still more than a little rough around the edges, the release was a significant success and was followed by the - more robust and easier to install FreeBSD 2.0.5 release in June of + more robust and easier to install FreeBSD 2.0.5 release in June of 1995. - We released FreeBSD 2.1.5 in August of 1996, and it appeared + We released FreeBSD 2.1.5 in August of 1996, and it appeared to be popular enough among the ISP and commercial communities that another release along the 2.1-STABLE branch was merited. This was - FreeBSD 2.1.7.1, released in February 1997 and capping the end of + FreeBSD 2.1.7.1, released in February 1997 and capping the end of mainstream development on 2.1-STABLE. Now in maintenance mode, only security enhancements and other critical bug fixes will be done on this branch (RELENG_2_1_0). - FreeBSD 2.2 was branched from the development mainline + FreeBSD 2.2 was branched from the development mainline (-CURRENT) in November 1996 as the RELENG_2_2 branch, and the first full release (2.2.1) was released in April 1997. Further releases along the 2.2 branch were done in the summer and fall of '97, the last of which (2.2.8) appeared in November 1998. The first official 3.0 release appeared in October 1998 and spelled the beginning of the end for the 2.2 branch. The tree branched again on Jan 20, 1999, leading to the 4.0-CURRENT and 3.X-STABLE branches. From 3.X-STABLE, 3.1 was released on February 15, 1999, 3.2 on May 15, 1999, 3.3 on September 16, 1999, 3.4 on December 20, 1999, and 3.5 on June 24, 2000, which was followed a few days later by a minor point release update to 3.5.1, to incorporate some last-minute security fixes to Kerberos. This will be the final release in the 3.X branch. There was another branch on March 13, 2000, which saw the emergence of the 4.X-STABLE branch, now considered to be the "current -stable branch". There have been several releases from it so far: 4.0-RELEASE came out in March 2000, 4.1 was released in July 2000, 4.2 in November 2000, 4.3 in April 2001, and 4.4 in September 2001. There will be more releases along the 4.X-stable (RELENG_4) branch well into 2002. Long-term development projects continue to take place in the 5.0-CURRENT (trunk) branch, and SNAPshot releases of 5.0 on CDROM (and, of course, on the net) are continually made available from the snapshot server as work progresses. Jordan Hubbard Contributed by FreeBSD Project Goals FreeBSD Project Goals The goals of the FreeBSD Project are to provide software that may be used for any purpose and without strings attached. Many of us have a significant investment in the code (and project) and would certainly not mind a little financial compensation now and then, but we are definitely not prepared to insist on it. We believe that our first and foremost mission is to provide code to any and all comers, and for whatever purpose, so that the code gets the widest possible use and provides the widest possible benefit. This is, I believe, one of the most fundamental goals of Free Software and one that we enthusiastically support. GNU General Public License (GPL) GNU Lesser General Public License (LGPL) BSD Copyright That code in our source tree which falls under the GNU General Public License (GPL) or Library General Public License (LGPL) comes with slightly more strings attached, though at least on the side of enforced access rather than the usual opposite. Due to the additional complexities that can evolve in the commercial use of GPL software we do, however, prefer software submitted under the more relaxed BSD copyright when it is a reasonable option to do so. Satoshi Asami Contributed by The FreeBSD Development Model FreeBSD Project Development Model The development of FreeBSD is a very open and flexible process, FreeBSD being literally built from the contributions of hundreds of people around the world, as can be seen from our list of contributors. We are constantly on the lookout for new developers and ideas, and those interested in becoming more closely involved with the project need simply contact us at the &a.hackers;. The &a.announce; is also available to those wishing to make other FreeBSD users aware of major areas of work. Useful things to know about the FreeBSD project and its development process, whether working independently or in close cooperation: The CVS repository CVS repository Concurrent Versions System CVS The central source tree for FreeBSD is maintained by CVS (Concurrent Versions System), a freely available source code control tool that comes bundled with FreeBSD. The primary CVS repository resides on a machine in Santa Clara CA, USA from where it is replicated to numerous mirror machines throughout the world. The CVS tree, as well as the -CURRENT and -STABLE trees which are checked out of it, can be easily replicated to your own machine as well. Please refer to the Synchronizing your source tree section for more information on doing this. The committers list committers The committers are the people who have write access to the CVS tree, and are thus authorized to make modifications to the FreeBSD source (the term committer comes from the &man.cvs.1; commit command, which is used to bring new changes into the CVS repository). The best way of making submissions for review by the committers list is to use the &man.send-pr.1; command, though if something appears to be jammed in the system then you may also reach them by sending mail to the &a.committers;. The FreeBSD core team core team The FreeBSD core team would be equivalent to the board of directors if the FreeBSD Project were a company. The primary task of the core team is to make sure the project, as a whole, is in good shape and is heading in the right directions. Inviting dedicated and responsible developers to join our group of committers is one of the functions of the core team, as is the recruitment of new core team members as others move on. The current core team was elected from a pool of committer candidates in October 2000. Elections are held every 2 years. Some core team members also have specific areas of responsibility, meaning that they are committed to ensuring that some large portion of the system works as advertised. For a complete list of FreeBSD developers and their areas of responsibility, please see the Contributors List Most members of the core team are volunteers when it comes to FreeBSD development and do not benefit from the project financially, so commitment should also not be misconstrued as meaning guaranteed support. The board of directors analogy above is not actually very accurate, and it may be more suitable to say that these are the people who gave up their lives in favor of FreeBSD against their better judgment! Outside contributors contributors Last, but definitely not least, the largest group of developers are the users themselves who provide feedback and bug fixes to us on an almost constant basis. The primary way of keeping in touch with FreeBSD's more non-centralized development is to subscribe to the &a.hackers; (see mailing list info) where such things are discussed. The FreeBSD Contributors List is a long and growing one, so why not join it by contributing something back to FreeBSD today? Providing code is not the only way of contributing to the project; for a more complete list of things that need doing, please refer to the FreeBSD Project web site. In summary, our development model is organized as a loose set of concentric circles. The centralized model is designed for the convenience of the users of FreeBSD, who are thereby provided with an easy way of tracking one central code base, not to keep potential contributors out! Our desire is to present a stable operating system with a large set of coherent application programs that the users can easily install and use, and this model works very well in accomplishing that. All we ask of those who would join us as FreeBSD developers is some of the same dedication its current people have to its continued success! The Current FreeBSD Release NetBSD OpenBSD 386BSD Free Software Foundation U.C. Berkeley Computer Systems Research Group (CSRG) FreeBSD is a freely available, full source 4.4BSD-Lite based release for Intel i386, i486, Pentium, Pentium Pro, Celeron, - Pentium II, Pentium III (or compatible) and DEC Alpha based computer + Pentium II, Pentium III (or compatible) and DEC Alpha based computer systems. It is based primarily on software from U.C. Berkeley's CSRG group, with some enhancements from NetBSD, OpenBSD, 386BSD, and the Free Software Foundation. - Since our release of FreeBSD 2.0 in late 94, the performance, + Since our release of FreeBSD 2.0 in late 94, the performance, feature set, and stability of FreeBSD has improved dramatically. The largest change is a revamped virtual memory system with a merged VM/file buffer cache that not only increases performance, but also - reduces FreeBSD's memory footprint, making a 5MB configuration a + reduces FreeBSD's memory footprint, making a 5 MB configuration a more acceptable minimum. Other enhancements include full NIS client and server support, transaction TCP support, dial-on-demand PPP, integrated DHCP support, an improved SCSI subsystem, ISDN support, - support for ATM, FDDI, Fast and Gigabit Ethernet (1000Mbit) + support for ATM, FDDI, Fast and Gigabit Ethernet (1000 Mbit) adapters, improved support for the latest Adaptec controllers, and many hundreds of bug fixes. We have also taken the comments and suggestions of many of our users to heart and have attempted to provide what we hope is a more sane and easily understood installation process. Your feedback on this (constantly evolving) process is especially welcome! In addition to the base distributions, FreeBSD offers a ported software collection with thousands of commonly sought-after programs. At the time of this printing, there were over &os.numports; ports! The list of ports ranges from http (WWW) servers, to games, languages, editors, and almost everything in between. The entire ports collection requires - approximately 100MB of storage, all ports being expressed as + approximately 100 MB of storage, all ports being expressed as deltas to their original sources. This makes it much easier for us to update ports, and greatly reduces the disk space demands made by the older 1.0 ports collection. To compile a port, you simply change to the directory of the program you wish to install, type make install, and let the system do the rest. The full original distribution for each port you build is retrieved dynamically off the CDROM or a local FTP site, so you need only enough disk space to build the ports you want. Almost every port is also provided as a pre-compiled package, which can be installed with a simple command (pkg_add) by those who do not wish to compile their own ports from source. A number of additional documents which you may find very helpful in the process of installing and using FreeBSD may now also be found in the /usr/share/doc directory on any machine - running FreeBSD 2.1 or later. You may view the locally installed + running FreeBSD 2.1 or later. You may view the locally installed manuals with any HTML capable browser using the following URLs: The FreeBSD Handbook /usr/share/doc/handbook/index.html The FreeBSD FAQ /usr/share/doc/faq/index.html You can also view the master (and most frequently updated) copies at http://www.FreeBSD.org/.