NAME¶
nfsd —
remote NFS server
SYNOPSIS¶
nfsd |
[-arduteo]
[-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
interfaces. 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 specified 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
- The new NFS server that includes NFSv4 support is now the
default, so this option is now a no-op and should be considered
deprecated.
- -o
- Forces the use of the old NFS server that does not include
NFSv4 support in it.
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 concurrency
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 ALSO¶
nfsstat(1),
kldload(2),
nfssvc(2),
nfsv4(4),
exports(5),
stablerestart(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.