NFSD(8)                   BSD System Manager's Manual                  NFSD(8)

NAME
     nfsd -- NFS server daemon

SYNOPSIS
     nfsd [command]
     nfsd [-F exports_file] checkexports
     nfsd [-NRrtuv] [-F exports_file] [-n num_servers] [-p nfsport]
          [-P mountport] [command]

DESCRIPTION
     nfsd runs on an NFS server machine to service NFS and MOUNT protocol
     requests from NFS client machines.  In order for a machine to act as an
     NFS server an NFS exports file, /etc/exports, must exist and the nfsd
     service must be enabled.

     nfsd listens for NFS service requests at the port indicated in the NFS
     server specification(2049) and the mountd thread listens for MOUNT ser-
     vice requests at an available port registered with portmap(8).

     For more information on the NFS and MOUNT protocols see Network File
     System Protocol Specification, RFC1094 and NFS: Network File System
     Version 3 Protocol Specification.

     The nfsd daemon is a multi-threaded process that includes a number of
     threads processing NFS requests, a thread to accept new socket connec-
     tions and a thread that processes NFS MOUNT protocol requests.

     When nfsd is started, it loads the export host addresses and options into
     the kernel using the nfssvc(2) system call.  After changing the list of
     exports (either directly or indirectly via a change in netgroup member-
     ship), a hangup signal should be sent to the daemon to get it to reload
     the export information.  This can be accomplished with the update command
     described below.

     Any errors encountered while processing the export entries will be logged
     via syslog(3).

     nfsd is normally launched by launchd(8); however, the nfsd command may
     also be used to manipulate the service using the following commands:

     enable   Enables the nfsd service.

     disable  Disables the nfsd service.

     start    Starts the nfsd service.  Note: if the service is disabled it
              will not be restarted on reboot.  Use the enable command to make
              the change permanent.

     stop     Stops the nfsd service.  Note: if the service is enabled it will
              be restarted on reboot.  Use the disable command to make the
              change permanent.

     restart  Restarts the nfsd service (by stopping the service - it will
              restart automatically if the /etc/exports file exists).

     update   Sends a SIGHUP to the running nfsd daemon to cause it to update
              its configuration.

     status   Displays whether the nfsd service is enabled and whether the
              nfsd daemon is currently running.

     checkexports
              Checks the exports file and reports any errors (to stderr).
              Note that this can be useful to verify the validity of an alter-
              nate exports file (using the -F option below) prior to putting
              the changes in place and updating nfsd.

     verbose [up|down]+
              Sends USR1 and/or USR2 signal(s) to the running nfsd daemon to
              cause it to increase and/or decrease its logging level.  (See
              below for details about nfsd's logging).

     Logging is performed via syslog(3) using the LOG_DAEMON facility.  By
     default, only messages up to priority LOG_WARNING are logged.  Setting
     the verbose level to one will add LOG_NOTICE messages which includes log-
     ging failed mount attempts.  A verbose level of two will increase the log
     level to LOG_INFO which includes logging successful mount attempts.  A
     log level of three or more will add LOG_DEBUG messages and cause increas-
     ing amounts of debug information to be logged.  The debug information
     exposes lots of information about nfsd's inner workings which is typi-
     cally only useful to developers.  Note: the syslog(8) configuration may
     need to be adjusted in order to see the increased verbosity.

     The nfsd utility exits 0 on success, and >0 if an error occurs.  When
     given the status command, it exits 0 if the service is enabled, and 1 if
     the service is disabled.

     The following is a list of command line options that are available.  How-
     ever, since nfsd is normally started by launchd(8), configuration of
     these options should be controlled using the equivalent settings in the
     NFS configuration file (see nfs.conf(5)).

     -F exports_file
             The exports_file argument specifies an alternate location for the
             exports file (useful with the checkexports command).

     -N      Allow non-root mount requests to be served.  This should only be
             specified if there are clients that require it.

     -P #    Specifies which port to use for the MOUNT service.

     -R      Allow mount RPCs requests for regular files to be served.
             Although this seems to violate the mount protocol specification,
             some diskless workstations do mount requests for their swapfiles
             and expect them to be regular files.  Since a regular file cannot
             be specified in /etc/exports, the -alldirs option will need to be
             used on the export in which the swap files reside.

     -n #    Specifies how many NFS server threads to create.

     -p #    Specifies which port to use for the NFS service (instead of the
             default of 2049).

     -r      Register the NFS service with portmap(8).  This option can be
             used to re-register the NFS services if the portmap server is
             restarted.  This option is equivalent to the update command.

     -t      Serve TCP NFS clients.  Note: only TCP will be used if no other
             options are specified.

     -u      Serve UDP NFS clients.  Note: only UDP will be used if no other
             options are specified.

     -v      Increase nfsd's logging level by one (may be used multiple
             times).

CONFIGURATION
     Unless otherwise specified, eight NFS server threads are started and both
     UDP and TCP transports are supported.

     A server should run enough threads to handle the maximum level of concur-
     rency from its clients.

     See nfs.conf(5) for a list of tunable parameters.

NOTES
     The exports list displayed via showmount(8) may contain additional infor-
     mation about the status of each export.  This information is reported as
     entries in the export's group list.

     If an export is currently unavailable, the group list will begin with the
     entry "<offline>" (or "<offline*>" if it is unavailable to some but not
     all clients exported to).

     If an export allows non-default security mechanisms, the group list will
     contain an entry indicating what security mechanisms are allowed.  For
     example: "<krb5:sys>".  The mechanisms are listed in no particular order
     and may not be available to all clients.

     If an export is available to all clients, the group list is usually
     empty.  But if additional status information is returned in the group
     list, then the list will also contain an explicit "(Everyone)" entry to
     indicate that the export is available to all clients.

FILES
     /etc/exports           The list of exported filesystems.
     /var/run/nfsd.pid      The pid of the currently running nfsd.
     /var/run/mountd.pid    The pid of the currently running mountd (provided
                            for backwards compatibility with scripts that may
                            HUP mountd to update exports).
     /var/run/mountdtab     The current list of outstanding mounts served.
     /var/run/mountdexptab  Information about exported file systems and direc-
                            tories (UUIDs, handles,
     /System/Library/LaunchDaemons/com.apple.nfsd.plist
                            The nfsd service's property list file for
                            launchd(8).

SEE ALSO
     exports(5), nfs.conf(5), showmount(8), nfsstat(1), nfssvc(2), portmap(8),
     rpc.rquotad(8), launchd(8)

HISTORY
     The nfsd and mountd utilities first appeared in 4.4BSD.  mountd function-
     ality was merged into nfsd in Darwin 9.

BSD                            November 10, 2008                           BSD