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 August 10, 2014 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 maxthreads Ar max_threads 45.Op 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 maxthreads 82and 83.Fl minthreads 84with their respective arguments to 85.Ar threads . 86.It Fl maxthreads Ar threads 87Specifies the maximum servers that will be kept around to service requests. 88.It 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 115The new NFS server that includes NFSv4 support is now the default, so this 116option is now a no-op and should be considered deprecated. 117.It Fl o 118Forces the use of the old NFS server that does not include NFSv4 support 119in it. 120.El 121.Pp 122For example, 123.Dq Li "nfsd -u -t -n 6" 124serves 125.Tn UDP 126and 127.Tn TCP 128transports using six daemons. 129.Pp 130A server should run enough daemons to handle 131the maximum level of concurrency from its clients, 132typically four to six. 133.Pp 134The 135.Nm 136utility listens for service requests at the port indicated in the 137.Tn NFS 138server specification; see 139.%T "Network File System Protocol Specification" , 140RFC1094, 141.%T "NFS: Network File System Version 3 Protocol Specification" , 142RFC1813 and 143.%T "Network File System (NFS) Version 4 Protocol" , 144RFC3530. 145.Pp 146If 147.Nm 148detects that 149.Tn NFS 150is not loaded in the running kernel, it will attempt 151to load a loadable kernel module containing 152.Tn NFS 153support using 154.Xr kldload 2 . 155If this fails, or no 156.Tn NFS 157KLD is available, 158.Nm 159will exit with an error. 160.Pp 161If 162.Nm 163is to be run on a host with multiple interfaces or interface aliases, use 164of the 165.Fl h 166option is recommended. 167If you do not use the option NFS may not respond to 168UDP packets from the same IP address they were sent to. 169Use of this option 170is also recommended when securing NFS exports on a firewalling machine such 171that the NFS sockets can only be accessed by the inside interface. 172The 173.Nm ipfw 174utility 175would then be used to block nfs-related packets that come in on the outside 176interface. 177.Pp 178If the server has stopped servicing clients and has generated a console message 179like 180.Dq Li "nfsd server cache flooded..." , 181the value for vfs.nfsd.tcphighwater needs to be increased. 182This should allow the server to again handle requests without a reboot. 183Also, you may want to consider decreasing the value for 184vfs.nfsd.tcpcachetimeo to several minutes (in seconds) instead of 12 hours 185when this occurs. 186.Pp 187Unfortunately making vfs.nfsd.tcphighwater too large can result in the mbuf 188limit being reached, as indicated by a console message 189like 190.Dq Li "kern.ipc.nmbufs limit reached" . 191If you cannot find values of the above 192.Nm sysctl 193values that work, you can disable the DRC cache for TCP by setting 194vfs.nfsd.cachetcp to 0. 195.Pp 196The 197.Nm 198utility has to be terminated with 199.Dv SIGUSR1 200and cannot be killed with 201.Dv SIGTERM 202or 203.Dv SIGQUIT . 204The 205.Nm 206utility needs to ignore these signals in order to stay alive as long 207as possible during a shutdown, otherwise loopback mounts will 208not be able to unmount. 209If you have to kill 210.Nm 211just do a 212.Dq Li "kill -USR1 <PID of master nfsd>" 213.Sh EXIT STATUS 214.Ex -std 215.Sh SEE ALSO 216.Xr nfsstat 1 , 217.Xr kldload 2 , 218.Xr nfssvc 2 , 219.Xr nfsv4 4 , 220.Xr exports 5 , 221.Xr stablerestart 5 , 222.Xr gssd 8 , 223.Xr ipfw 8 , 224.Xr mountd 8 , 225.Xr nfsiod 8 , 226.Xr nfsrevoke 8 , 227.Xr nfsuserd 8 , 228.Xr rpcbind 8 229.Sh HISTORY 230The 231.Nm 232utility first appeared in 233.Bx 4.4 . 234.Sh BUGS 235If 236.Nm 237is started when 238.Xr gssd 8 239is not running, it will service AUTH_SYS requests only. To fix the problem 240you must kill 241.Nm 242and then restart it, after the 243.Xr gssd 8 244is running. 245