Index: head/usr.sbin/nfsd/nfsd.8 =================================================================== --- head/usr.sbin/nfsd/nfsd.8 (revision 336797) +++ head/usr.sbin/nfsd/nfsd.8 (revision 336798) @@ -1,344 +1,351 @@ .\" Copyright (c) 1989, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)nfsd.8 8.4 (Berkeley) 3/29/95 .\" $FreeBSD$ .\" -.Dd June 30, 2018 +.Dd July 27, 2018 .Dt NFSD 8 .Os .Sh NAME .Nm nfsd .Nd remote .Tn NFS server .Sh SYNOPSIS .Nm .Op Fl ardute .Op Fl n Ar num_servers .Op Fl h Ar bindip .Op Fl p Ar pnfs_setup .Op Fl m Ar mirror_level .Op Fl Fl maxthreads Ar max_threads .Op Fl Fl minthreads Ar min_threads .Sh DESCRIPTION The .Nm utility runs on a server machine to service .Tn NFS requests from client machines. At least one .Nm must be running for a machine to operate as a server. .Pp Unless otherwise specified, eight servers per CPU for .Tn UDP transport are started. .Pp The following options are available: .Bl -tag -width Ds .It Fl r Register the .Tn NFS service with .Xr rpcbind 8 without creating any servers. This option can be used along with the .Fl u or .Fl t options to re-register NFS if the rpcbind server is restarted. .It Fl d Unregister the .Tn NFS service with .Xr rpcbind 8 without creating any servers. .It Fl n Ar threads Specifies how many servers to create. This option is equivalent to specifying .Fl Fl maxthreads and .Fl Fl minthreads with their respective arguments to .Ar threads . .It Fl Fl maxthreads Ar threads Specifies the maximum servers that will be kept around to service requests. .It Fl Fl minthreads Ar threads Specifies the minimum servers that will be kept around to service requests. .It Fl h Ar bindip Specifies which IP address or hostname to bind to on the local host. This option is recommended when a host has multiple interfaces. Multiple .Fl h options may be specified. .It Fl a Specifies that nfsd should bind to the wildcard IP address. This is the default if no .Fl h options are given. It may also be specified in addition to any .Fl h options given. Note that NFS/UDP does not operate properly when bound to the wildcard IP address whether you use -a or do not use -h. .It Fl p Ar pnfs_setup Enables pNFS support in the server and specifies the information that the daemon needs to start it. This option can only be used on one server and specifies that this server will be the MetaData Server (MDS) for the pNFS service. This can only be done if there is at least one FreeBSD system configured as a Data Server (DS) for it to use. .Pp The .Ar pnfs_setup string is a set of fields separated by ',' characters: .Bl -tag -width Ds -Each of these fields specifies one Data Server. +Each of these fields specifies one DS. It consists of a server hostname, followed by a ':' and the directory path where the DS's data storage file system is mounted on this MDS server. -At this time, only IPv4 addresses are supported by the interface to the kernel, -so the -.Dq server hostname -must resolve to an IPv4 address and support mounts on that address. -This needs to be extended to support IPv6 addresses in the near future. This can optionally be followed by a '#' and the mds_path, which is the directory path for an exported file system on this MDS. If this is specified, it means that this DS is to be used to store data files for this mds_path file system only. If this optional component does not exist, the DS will be used to store data files for all exported MDS file systems. The DS storage file systems must be mounted on this system before the .Nm is started with this option specified. .br For example: .sp nfsv4-data0:/data0,nfsv4-data1:/data1 .sp would specify two DS servers called nfsv4-data0 and nfsv4-data1 that comprise the data storage component of the pNFS service. These two DSs would be used to store data files for all exported file systems on this MDS. The directories .Dq /data0 and .Dq /data1 are where the data storage servers exported storage directories are mounted on this system (which will act as the MDS). .br Whereas, for the example: .sp nfsv4-data0:/data0#/export1,nfsv4-data1:/data1#/export2 .sp would specify two DSs as above, however nfsv4-data0 will be used to store data files for .Dq /export1 and nfsv4-data1 will be used to store data files for .Dq /export2 . .El +.sp +When using IPv6 addresses for DSs +be wary of using link local addresses. +The IPv6 address for the DS is sent to the client and there is no scope +zone in it. +As such, a link local address may not work for a pNFS client to DS +TCP connection. +When parsed, +.Nm +will only use a link local address if it is the only address returned by +.Xr getaddrinfo 3 +for the DS hostname. .It Fl m Ar mirror_level This option is only meaningful when used with the .Fl p option. It specifies the .Dq mirror_level , which defines how many of the DSs will have a copy of a file's data storage file. The default of one implies no mirroring of data storage files on the DSs. The .Dq mirror_level would normally be set to 2 to enable mirroring, but can be as high as NFSDEV_MAXMIRRORS. There must be at least .Dq mirror_level DSs for each exported file system on the MDS, as specified in the .Fl p option. This implies that, for the above example using "#/export1" and "#/export2", mirroring cannot be done. There would need to be two DS entries for each of "#/export1" and "#/export2" in order to support a .Dq mirror_level of two. .Pp If mirroring is enabled, the server must use the Flexible File layout. If mirroring is not enabled, the server will use the File layout by default, but this default can be changed to the Flexible File layout if the .Xr sysctl 1 vfs.nfsd.default_flexfile is set non-zero. .It Fl t Serve .Tn TCP NFS clients. .It Fl u Serve .Tn UDP NFS clients. .It Fl e Ignored; included for backward compatibility. .El .Pp For example, .Dq Li "nfsd -u -t -n 6" serves .Tn UDP and .Tn TCP transports using six daemons. .Pp A server should run enough daemons to handle the maximum level of concurrency from its clients, typically four to six. .Pp The .Nm utility listens for service requests at the port indicated in the .Tn NFS server specification; see .%T "Network File System Protocol Specification" , RFC1094, .%T "NFS: Network File System Version 3 Protocol Specification" , RFC1813, .%T "Network File System (NFS) Version 4 Protocol" , RFC3530 and .%T "Network File System (NFS) Version 4 Minor Version 1 Protocol" , RFC5661. .Pp If .Nm detects that .Tn NFS is not loaded in the running kernel, it will attempt to load a loadable kernel module containing .Tn NFS support using .Xr kldload 2 . If this fails, or no .Tn NFS KLD is available, .Nm will exit with an error. .Pp If .Nm is to be run on a host with multiple interfaces or interface aliases, use of the .Fl h option is recommended. If you do not use the option NFS may not respond to UDP packets from the same IP address they were sent to. Use of this option is also recommended when securing NFS exports on a firewalling machine such that the NFS sockets can only be accessed by the inside interface. The .Nm ipfw utility would then be used to block nfs-related packets that come in on the outside interface. .Pp If the server has stopped servicing clients and has generated a console message like .Dq Li "nfsd server cache flooded..." , the value for vfs.nfsd.tcphighwater needs to be increased. This should allow the server to again handle requests without a reboot. Also, you may want to consider decreasing the value for vfs.nfsd.tcpcachetimeo to several minutes (in seconds) instead of 12 hours when this occurs. .Pp Unfortunately making vfs.nfsd.tcphighwater too large can result in the mbuf limit being reached, as indicated by a console message like .Dq Li "kern.ipc.nmbufs limit reached" . If you cannot find values of the above .Nm sysctl values that work, you can disable the DRC cache for TCP by setting vfs.nfsd.cachetcp to 0. .Pp The .Nm utility has to be terminated with .Dv SIGUSR1 and cannot be killed with .Dv SIGTERM or .Dv SIGQUIT . The .Nm utility needs to ignore these signals in order to stay alive as long as possible during a shutdown, otherwise loopback mounts will not be able to unmount. If you have to kill .Nm just do a .Dq Li "kill -USR1 " .Sh EXIT STATUS .Ex -std .Sh SEE ALSO .Xr nfsstat 1 , .Xr kldload 2 , .Xr nfssvc 2 , .Xr nfsv4 4 , .Xr pnfs 4 , .Xr exports 5 , .Xr stablerestart 5 , .Xr gssd 8 , .Xr ipfw 8 , .Xr mountd 8 , .Xr nfsiod 8 , .Xr nfsrevoke 8 , .Xr nfsuserd 8 , .Xr rpcbind 8 .Sh HISTORY The .Nm utility first appeared in .Bx 4.4 . .Sh BUGS If .Nm is started when .Xr gssd 8 is not running, it will service AUTH_SYS requests only. To fix the problem you must kill .Nm and then restart it, after the .Xr gssd 8 is running. .Pp If mirroring is enabled via the .Fl m option and there are Linux clients doing NFSv4.1 mounts, those clients need to be patched to support the .Dq tightly coupled variant of the Flexible File layout or the .Xr sysctl 1 vfs.nfsd.flexlinuxhack must be set to one on the MDS as a workaround.