1.\" Copyright (c) 1989, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 4. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)nfsd.8 8.4 (Berkeley) 3/29/95 29.\" $FreeBSD$ 30.\" 31.Dd January 1, 2015 32.Dt NFSD 8 33.Os 34.Sh NAME 35.Nm nfsd 36.Nd remote 37.Tn NFS 38server 39.Sh SYNOPSIS 40.Nm 41.Op Fl arduteo 42.Op Fl n Ar num_servers 43.Op Fl h Ar bindip 44.Op Fl Fl maxthreads Ar max_threads 45.Op Fl Fl minthreads Ar min_threads 46.Sh DESCRIPTION 47The 48.Nm 49utility runs on a server machine to service 50.Tn NFS 51requests from client machines. 52At least one 53.Nm 54must be running for a machine to operate as a server. 55.Pp 56Unless otherwise specified, eight servers per CPU for 57.Tn UDP 58transport are started. 59.Pp 60The following options are available: 61.Bl -tag -width Ds 62.It Fl r 63Register the 64.Tn NFS 65service with 66.Xr rpcbind 8 67without creating any servers. 68This option can be used along with the 69.Fl u 70or 71.Fl t 72options to re-register NFS if the rpcbind server is restarted. 73.It Fl d 74Unregister the 75.Tn NFS 76service with 77.Xr rpcbind 8 78without creating any servers. 79.It Fl n Ar threads 80Specifies how many servers to create. This option is equivalent to specifying 81.Fl Fl maxthreads 82and 83.Fl Fl minthreads 84with their respective arguments to 85.Ar threads . 86.It Fl Fl maxthreads Ar threads 87Specifies the maximum servers that will be kept around to service requests. 88.It Fl Fl minthreads Ar threads 89Specifies the minimum servers that will be kept around to service requests. 90.It Fl h Ar bindip 91Specifies which IP address or hostname to bind to on the local host. 92This option is recommended when a host has multiple interfaces. 93Multiple 94.Fl h 95options may be specified. 96.It Fl a 97Specifies that nfsd should bind to the wildcard IP address. 98This is the default if no 99.Fl h 100options are given. 101It may also be specified in addition to any 102.Fl h 103options given. 104Note that NFS/UDP does not operate properly when 105bound to the wildcard IP address whether you use -a or do not use -h. 106.It Fl t 107Serve 108.Tn TCP NFS 109clients. 110.It Fl u 111Serve 112.Tn UDP NFS 113clients. 114.It Fl e 115Enable NFSv4 support. 116It is enabled by default; this option should be considered deprecated. 117.It Fl o 118Disable NFSv4 support. 119.El 120.Pp 121For example, 122.Dq Li "nfsd -u -t -n 6" 123serves 124.Tn UDP 125and 126.Tn TCP 127transports using six daemons. 128.Pp 129A server should run enough daemons to handle 130the maximum level of concurrency from its clients, 131typically four to six. 132.Pp 133The 134.Nm 135utility listens for service requests at the port indicated in the 136.Tn NFS 137server specification; see 138.%T "Network File System Protocol Specification" , 139RFC1094, 140.%T "NFS: Network File System Version 3 Protocol Specification" , 141RFC1813 and 142.%T "Network File System (NFS) Version 4 Protocol" , 143RFC3530. 144.Pp 145If 146.Nm 147detects that 148.Tn NFS 149is not loaded in the running kernel, it will attempt 150to load a loadable kernel module containing 151.Tn NFS 152support using 153.Xr kldload 2 . 154If this fails, or no 155.Tn NFS 156KLD is available, 157.Nm 158will exit with an error. 159.Pp 160If 161.Nm 162is to be run on a host with multiple interfaces or interface aliases, use 163of the 164.Fl h 165option is recommended. 166If you do not use the option NFS may not respond to 167UDP packets from the same IP address they were sent to. 168Use of this option 169is also recommended when securing NFS exports on a firewalling machine such 170that the NFS sockets can only be accessed by the inside interface. 171The 172.Nm ipfw 173utility 174would then be used to block nfs-related packets that come in on the outside 175interface. 176.Pp 177If the server has stopped servicing clients and has generated a console message 178like 179.Dq Li "nfsd server cache flooded..." , 180the value for vfs.nfsd.tcphighwater needs to be increased. 181This should allow the server to again handle requests without a reboot. 182Also, you may want to consider decreasing the value for 183vfs.nfsd.tcpcachetimeo to several minutes (in seconds) instead of 12 hours 184when this occurs. 185.Pp 186Unfortunately making vfs.nfsd.tcphighwater too large can result in the mbuf 187limit being reached, as indicated by a console message 188like 189.Dq Li "kern.ipc.nmbufs limit reached" . 190If you cannot find values of the above 191.Nm sysctl 192values that work, you can disable the DRC cache for TCP by setting 193vfs.nfsd.cachetcp to 0. 194.Pp 195The 196.Nm 197utility has to be terminated with 198.Dv SIGUSR1 199and cannot be killed with 200.Dv SIGTERM 201or 202.Dv SIGQUIT . 203The 204.Nm 205utility needs to ignore these signals in order to stay alive as long 206as possible during a shutdown, otherwise loopback mounts will 207not be able to unmount. 208If you have to kill 209.Nm 210just do a 211.Dq Li "kill -USR1 <PID of master nfsd>" 212.Sh EXIT STATUS 213.Ex -std 214.Sh SEE ALSO 215.Xr nfsstat 1 , 216.Xr kldload 2 , 217.Xr nfssvc 2 , 218.Xr nfsv4 4 , 219.Xr exports 5 , 220.Xr stablerestart 5 , 221.Xr gssd 8 , 222.Xr ipfw 8 , 223.Xr mountd 8 , 224.Xr nfsiod 8 , 225.Xr nfsrevoke 8 , 226.Xr nfsuserd 8 , 227.Xr rpcbind 8 228.Sh HISTORY 229The 230.Nm 231utility first appeared in 232.Bx 4.4 . 233.Sh BUGS 234If 235.Nm 236is started when 237.Xr gssd 8 238is not running, it will service AUTH_SYS requests only. To fix the problem 239you must kill 240.Nm 241and then restart it, after the 242.Xr gssd 8 243is running. 244