nfsd

NAME

       nfsd - NFS service daemon

SYNOPSIS

       /usr/sbin/rpc.nfsd   [ -f exports-file ]   [ -d facility ]
       [ -P port ]       [ -Fhnprstv ]       [ --debug facility ]
       [ --exports-file=file ]     [ --foreground ]    [ --help ]
       [ --allow-non-root ]    [ --re-export ]    [ --port port ]
       [ --version ] [ numservers ]

DESCRIPTION

       The  nfsd  program  is  an NFS service daemon that handles
       client filesystem requests.  Unlike on some other systems,
       nfsd  operates as a normal user-level process.  The server
       also differs from other NFS server implementations in that
       it  mounts  an  entire  file  hierarchy not limited by the
       boundaries of physical file-systems.   The  implementation
       allows  the  clients read-only or read-write access to the
       file hierarchy of the server machine.

       The mountd program starts an  ancillary  user-level  mount
       daemon.

OPTIONS

       -f or --exports-file
              This option specifies the exports file, listing the
              clients that this server is prepared to  serve  and
              parameters   to  apply  to  each  such  mount  (see
              exports(5)).  By  default  exports  are  read  from
              /etc/exports.

       -d facility or --debug facility
              Log operations verbosely. Legal values for facility
              are currently call for the logging of RPC calls and
              arguments, fhcache for the file handle cache opera-
              tion, auth for  the  authentication  routines,  and
              ugid  for the uid mapping code, if used. Debug mes-
              sages will be logged to syslog(8) unless the daemon
              runs in the foreground.

       -F or --foreground
              Unlike  in  normal  operation, nfsd will not detach
              from the terminal  when  given  this  option.  When
              debugging is requested, it will be sent to standard
              error.

       -h or --help
              Provide a short help summary.

       -n or --allow-non-root
              Allow incoming NFS requests to be honored  even  if
              they do not originate from reserved IP ports.  Some
              older  NFS  client  implementations  require  this.
              Some newer NFS client implementations don't believe
              in reserved port checking. This check can be turned
              off for individual hosts by specifying the insecure
              export option in /etc/exports.

       -P portnum or --port portnum
              Makes nfsd listen on port portnum  instead  of  the
              default port 2049.

       -p or --promiscuous
              Put  the server into promiscuous mode where it will
              serve any host on the network.

       -r or --re-export
              Allow imported NFS  file-systems  to  be  exported.
              This can be used to turn a machine into an NFS mul-
              tiplier.  Caution should be used when  re-exporting
              loopback  NFS  mounts because re-entering the mount
              point will  result  in  deadlock  between  the  NFS
              client and the NFS server.

       -v or --version
              Report the current version number of the program.

       numcopies
              This  is  an experimental feature that lets you run
              several instances of nfsd in parallel. When given a
              value of numcopies greater than one, nfsd will fork
              as many times as specified by this value.  However,
              the  servers  do  not  share  a  common file handle
              cache, which makes certain file operations impossi-
              ble.

              For this reason, nfsd will disallow all write oper-
              ations when invoked with this option. Although this
              is very limiting, this feature may still prove use-
              ful for exporting public FTP areas or  Usenet  News
              spools.  Note  that  (at  best)  you  won't see any
              improvements when measuring throughput with a  sin-
              gle  reader,  or  with  several readers on a single
              host whose NFS  client  implementation  is  single-
              threaded  and  does  no read-ahead (as Linux's cur-
              rently is).

SIGNALS

       nfsd recognizes the following signals:

       SIGHUP causes nfsd to re-read the export  file  and  flush
              the file handle cache.

       SIGUSR1
              When nfsd was invoked with debugging options, send-
              ing this signal toggles generation of debug  infor-
              mation.

       SIGIOT When   compiled   with  with  the  -DCALL_PROFILING
              option, sending a SIGIOT to nfsd  will  cause  dump
              the  average execution times per NFS operation into
              /tmp/nfsd.profile.

SEE ALSO

       exports(5), mountd(8), ugidd(8C)

AUTHORS

       Mark Shand wrote the orignal unfsd.  Don  Becker  extended
       unfsd  to  support  authentication  and  allow  read-write
       access and called it hnfs.  Rick Sladkey added host match-
       ing,  showmount  -e  support, mountd authentication, inetd
       support, and all  of  the  portability  and  configuration
       code.   Olaf  Kirch  fixed  one  or two security holes and
       other bugs, added the uid mapping and a  couple  of  other
       things.