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rpc.mountd(8)							 rpc.mountd(8)



NAME
       rpc.mountd - NFS mount daemon

SYNOPSIS
       /usr/sbin/rpc.mountd [options]

DESCRIPTION
       The  rpc.mountd program implements the NFS mount protocol. When receiv-
       ing a MOUNT request from an NFS client, it checks the  request  against
       the list of currently exported file systems. If the client is permitted
       to mount	 the  file  system,  rpc.mountd	 obtains  a  file  handle  for
       requested directory and returns it to the client.

   Exporting NFS File Systems
       Making file systems available to NFS clients is called exporting.

       Usually, a file system and the hosts it should be made available to are
       listed in the /etc/exports file, and invoking exportfs -a whenever  the
       system  is  booted.  The	 exportfs(8)  command makes export information
       available to both the kernel NFS server module and the rpc.mountd  dae-
       mon.

       Alternatively,  you can export individual directories temporarily using
       exportfs's host:/directory syntax.

   The rmtab File
       For every mount request received from an NFS client, rpc.mountd adds an
       entry  to  the  /var/lib/nfs/rmtab  file.  When	receiving  an  unmount
       request, that entry is removed.

       However, this file is mostly ornamental. One, the client	 can  continue
       to  use	the file handle even after calling rpc.mountd 's UMOUNT proce-
       dure. And two, if a client reboots without  notifying  rpc.mountd  ,  a
       stale entry will remain in rmtab.

OPTIONS
       -d kind	or  --debug kind
	      Turn on debugging. Valid kinds are: all, auth, call, general and
	      parse.

       -F  or  --foreground
	      Run in foreground (do not daemonize)

       -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, export information  is
	      read from /etc/exports.

       -h  or  --help
	      Display usage message.

       -o num  or  --descriptors num
	      Set the limit of the number of open file descriptors to num. The
	      default is to leave the limit unchanged.

       -N  or  --no-nfs-version
	      This option can be used to request that rpc.mountd do not	 offer
	      certain  versions	 of NFS. The current version of rpc.mountd can
	      support both NFS version 2 and the newer version 3. If  the  NFS
	      kernel module was compiled without support for NFSv3, rpc.mountd
	      must be invoked with the option --no-nfs-version 3 .

       -n  or  --no-tcp
	      Don't advertise TCP for mount.

       -P     Ignored (compatibility with unfsd??).

       -p  or  --port num
	      Force rpc.mountd to bind to the specified port num,  instead  of
	      using the random port number assigned by the portmapper.

       -H  or  --ha-callout prog
	      Specify  a high availability callout program, which will receive
	      callouts for all client mount and unmount requests. This	allows
	      rpc.mountd  to be used in a High Availability NFS (HA-NFS) envi-
	      ronment. This callout is not needed (and	should	not  be	 used)
	      with  2.6	 and later kernels (instead, mount the nfsd filesystem
	      on /proc/fs/nfsd ).  The program will be	called	with  4	 argu-
	      ments.  The first will be mount or unmount depending on the rea-
	      son for the callout.  The second will be the name of the	client
	      performing  the  mount.	The  third  will  be the path that the
	      client is mounting.  The last is the number of concurrent mounts
	      that we believe the client has of that path.

       -s, --state-directory-path directory
	      specify  a  directory in which to place statd state information.
	      If this option is not specified the default of  /var/lib/nfs  is
	      used.

       -r, --reverse-lookup
	      mountd tracks IP addresses in the rmtab, and when a DUMP request
	      is made (by someone running  showmount  -a,  for	instance),  it
	      returns  IP  addresses  instead  of  hostnames  by default. This
	      option causes mountd to do a reverse lookup on each  IP  address
	      and  return that hostname instead. Enabling this can have a sub-
	      stantial negative effect on performance in some situations.

       -t N or --num-threads=N
	      This  option  specifies  the  number  of	worker	threads	  that
	      rpc.mountd  spawns.   The default is 1 thread, which is probably
	      enough.  More threads are usually only needed  for  NFS  servers
	      which need to handle mount storms of hundreds of NFS mounts in a
	      few seconds, or when your DNS server is slow or unreliable.

       -V  or  --nfs-version
	      This option can be used to request that rpc.mountd offer certain
	      versions	of  NFS. The current version of rpc.mountd can support
	      both NFS version 2 and the newer version 3.

       -v  or  --version
	      Print the version of rpc.mountd and exit.


TCP_WRAPPERS SUPPORT
       This rpc.mountd version is protected by the  tcp_wrapper	 library.  You
       have to give the clients access to rpc.mountd if they should be allowed
       to use it. To allow connects from clients of the	 .bar.com  domain  you
       could use the following line in /etc/hosts.allow:

       mountd: .bar.com

       You have to use the daemon name mountd for the daemon name (even if the
       binary has a different name).  Note: hostnames used  in	either	access
       file will be ignored when they can not be resolved into IP addresses.

       For  further  information  please  have	a  look	 at  the  tcpd(8)  and
       hosts_access(5) manual pages.

SEE ALSO
       rpc.nfsd(8), exportfs(8), exports(5), rpc.rquotad(8).

FILES
       /etc/exports, /var/lib/nfs/xtab.

AUTHOR
       Olaf Kirch, H. J. Lu, G. Allan Morris III, and a host of others.



				  31 Aug 2004			 rpc.mountd(8)
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