Command Section
NFSD(8)                 FreeBSD System Manager's Manual                NFSD(8)

     nfsd - remote NFS server

     nfsd [-ardute] [-n num_servers] [-h bindip] [--maxthreads max_threads]
          [--minthreads min_threads]

     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, eight servers per CPU for UDP transport are

     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 threads
             Specifies how many servers to create.  This option is equivalent
             to specifying --maxthreads and --minthreads with their respective
             arguments to threads.

     --maxthreads threads
             Specifies the maximum servers that will be kept around to service

     --minthreads threads
             Specifies the minimum servers that will be kept around to service

     -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      Ignored; included for backward compatibility.

     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
     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,

     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.

     If the server has stopped servicing clients and has generated a console
     message like ``nfsd server cache flooded...'', the value for
     vfs.nfsd.tcphighwater needs to be increased.  This should allow the
     server to again handle requests without a reboot.  Also, you may want to
     consider decreasing the value for vfs.nfsd.tcpcachetimeo to several
     minutes (in seconds) instead of 12 hours when this occurs.

     Unfortunately making vfs.nfsd.tcphighwater too large can result in the
     mbuf limit being reached, as indicated by a console message like
     ``kern.ipc.nmbufs limit reached''.  If you cannot find values of the
     above sysctl values that work, you can disable the DRC cache for TCP by
     setting vfs.nfsd.cachetcp to 0.

     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), nfsv4(4), exports(5),
     stablerestart(5), gssd(8), ipfw(8), mountd(8), nfsiod(8), nfsrevoke(8),
     nfsuserd(8), rpcbind(8)

     The nfsd utility first appeared in 4.4BSD.

     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.

FreeBSD 11.1-RELEASE-p4         April 25, 2015         FreeBSD 11.1-RELEASE-p4
Command Section