NFSD(8) BSD System Manager's Manual NFSD(8)
nfsd -- remote NFS server
nfsd [-ardut] [-n num_servers] [-h bindip]
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
-n Specifies how many servers to create.
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.
For example, ``nfsd -u -t -n 6'' serves UDP and TCP transports using six
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 and NFS: Network File System Version 3 Protocol
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>''
The nfsd utility exits 0 on success, and >0 if an error occurs.
nfsstat(1), kldload(2), nfssvc(2), exports(5), ipfw(8), mountd(8),
The nfsd utility first appeared in 4.4BSD.
BSD March 29, 1995 BSD