path: root/sbin/nfsd/nfsd.8

.\" 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. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. 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 March 29, 1995
.Dt NFSD 8
.Os
.Sh NAME
.Nm nfsd
.Nd remote
.Tn NFS
server
.Sh SYNOPSIS
.Nm
.Op Fl ardut
.Op Fl n Ar num_servers
.Op Fl h Ar bindip
.Sh DESCRIPTION
.Nm Nfsd
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, four servers 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
Specifies how many servers to create.
.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 t
Serve
.Tn TCP NFS
clients.
.It Fl u
Serve
.Tn UDP NFS
clients.
.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
.Nm Nfsd
listens for service requests at the port indicated in the
.Tn NFS
server specification; see
.%T "Network File System Protocol Specification" ,
RFC1094 and
.%T "NFS: Network File System Version 3 Protocol Specification" .
.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 8
by way of
.Xr vfsload 3 .
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.
.Nm Ipfw
would then be used to block nfs-related packets that come in on the outside
interface.
.Pp
.Nm
has to be terminated with
.Dv SIGUSR1
and cannot be killed with
.Dv SIGTERM
or
.Dv SIGQUIT .
.Nm
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 <PID of master nfsd>"
.Sh DIAGNOSTICS
.Ex -std
.Sh SEE ALSO
.Xr nfsstat 1 ,
.Xr nfssvc 2 ,
.Xr ipfw 8 ,
.Xr kldload 8 ,
.Xr mountd 8 ,
.Xr nfsiod 8 ,
.Xr rpcbind 8
.Sh HISTORY
The
.Nm
utility first appeared in
.Bx 4.4 .