NFSD(8) BSD System Manager's Manual NFSD(8)NAME
nfsd — remote NFS server
SYNOPSIS
nfsd [-ardute] [-n num_servers] [-h bindip]
DESCRIPTION
The nfsd utility runs on a server machine to service NFS requests from
client machines. At least one nfsd must be running for a machine to
operate as a server.
Unless otherwise specified, four servers for UDP transport are started.
The following options are available:
-r Register the NFS service with rpcbind(8) without creating any
servers. This option can be used along with the -u or -t options
to re-register NFS if the rpcbind server is restarted.
-d Unregister the NFS service with rpcbind(8) without creating any
servers.
-n Specifies how many servers to create.
-h bindip
Specifies which IP address or hostname to bind to on the local
host. This option is recommended when a host has multiple inter‐
faces. Multiple -h options may be specified.
-a Specifies that nfsd should bind to the wildcard IP address. This
is the default if no -h options are given. It may also be speci‐
fied in addition to any -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.
-t Serve TCP NFS clients.
-u Serve UDP NFS clients.
-e Forces nfsd to try and start the experimental server that
includes NFSv4 support in it. If this flag isn't specified, the
experimental server will only be started if it is linked into the
kernel and the regular one isn't.
ie. The kernel is built with the following:
# options NFSSERVER
options NFSD
For example, “nfsd -u -t -n 6” serves UDP and TCP transports using six
daemons.
A server should run enough daemons to handle the maximum level of concur‐
rency from its clients, typically four to six.
The nfsd utility listens for service requests at the port indicated in
the NFS server specification; see Network File System Protocol
Specification, RFC1094, NFS: Network File System Version 3 Protocol
Specification, RFC1813 and Network File System (NFS) Version 4 Protocol,
RFC3530.
If nfsd detects that NFS is not loaded in the running kernel, it will
attempt to load a loadable kernel module containing NFS support using
kldload(2). If this fails, or no NFS KLD is available, nfsd will exit
with an error.
If nfsd is to be run on a host with multiple interfaces or interface
aliases, use of the -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 ipfw utility would then be used to
block nfs-related packets that come in on the outside interface.
The nfsd utility has to be terminated with SIGUSR1 and cannot be killed
with SIGTERM or SIGQUIT. The nfsd 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 nfsd
just do a “kill -USR1 <PID of master nfsd>”
EXIT STATUS
The nfsd utility exits 0 on success, and >0 if an error occurs.
SEE ALSOnfsstat(1), kldload(2), nfssvc(2), nfsv4(4), exports(5), gssd(8),
ipfw(8), mountd(8), nfsiod(8), nfsrevoke(8), nfsuserd(8), rpcbind(8)HISTORY
The nfsd utility first appeared in 4.4BSD.
BUGS
If nfsd is started when gssd(8) is not running, it will service AUTH_SYS
requests only. To fix the problem you must kill nfsd and then restart it,
after the gssd(8) is running.
BSD March 29, 1995 BSD