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RedHat 9 (Linux i386) - man page for exportfs (redhat section 8)

exportfs(8)			     System Manager's Manual			      exportfs(8)

       exportfs - maintain list of NFS exported file systems

       /usr/sbin/exportfs [-avi] [-o options,..] [client:/path ..]
       /usr/sbin/exportfs -r [-v]
       /usr/sbin/exportfs [-av] -u [client:/path ..]
       /usr/sbin/exportfs [-v]

       The  exportfs  command  is used to maintain the current table of exported file systems for
       NFS. This list is kept in a separate file named /var/lib/nfs/xtab which is read by  mountd
       when  a	remote host requests access to mount a file tree, and parts of the list which are
       active are kept in the kernel's export table.

       Normally this xtab file is initialized  with  the  list	of  all  file  systems	named  in
       /etc/exports by invoking exportfs -a.

       However, administrators can choose to add and delete individual file systems without modi-
       fying /etc/exports using exportfs.

       Any export requests which identify a specific host (rather than a subnet or netgroup  etc)
       are  entered  directly  into  the  kernel's  export  table  as  well  as  being written to
       /var/lib/nfs/xtab.  Further, any mount points listed in /var/lib/nfs/rmtab which  match	a
       non host-specific export request will cause an appropriate export entry for the host given
       in rmtab to be entered into the kernel's export table.

       -a     Export or unexport all directories.

       -o options,...
	      Specify a list of export options in the same manner as in exports(5).

       -i     Ignore the /etc/exports file, so that only default options and options given on the
	      command line are used.

       -r     Reexport	all  directories. It synchronizes /var/lib/nfs/xtab with /etc/exports. It
	      removes entries in /var/lib/nfs/xtab  which  are	deleted  from  /etc/exports,  and
	      remove any entries from the kernel export table which are no longer valid.

       -u     Unexport one or more directories.

       -v     Be  verbose.  When  exporting or unexporting, show what's going on. When displaying
	      the current export list, also display the list of export options.

   Exporting Directories
       The first synopsis shows how to invoke the command when adding new entries to  the  export
       table.	When  using  exportfs -a, all directories in exports(5) are added to xtab and the
       resulting list is pushed into the kernel.

       The host:/path argument specifies the directory to export along with the host or hosts  to
       export  it to. All formats described in exports(5) are supported; to export a directory to
       the world, simply specify :/path.

       The export options for a particular  host/directory  pair  derive  from	several  sources.
       There  is  a  set  of  default  options which can be overridden by entries in /etc/exports
       (unless the -i option is given).  In addition, the administrator may overide  any  options
       from  these sources using the -o argument which takes a comma-separated list of options in
       the same fashion as one would specify them in exports(5).  Thus, exportfs can also be used
       to modify the export options of an already exported directory.

       Modifications  of  the  kernel  export  table used by nfsd(8) take place immediately after
       parsing the command line and updating the xtab file.

       The default export options are sync,ro,root_squash,no_delay.

   Unexporting Directories
       The third synopsis shows how to unexported a currently  exported  directory.   When  using
       exportfs  -ua,  all  entries listed in xtab are removed from the kernel export tables, and
       the file is cleared. This effectively shuts down all NFS activity.

       To remove individial export entries, one can specify a host:/path pair. This  deletes  the
       specified entry from xtab and removes the corresponding kernel entry (if any).

   Dumping the Export Table
       Invoking exportfs without further options shows the current list of exported file systems.
       When giving the -v option, the list of flags pertaining to each export are shown in  addi-

       The  following adds all directories listed in /etc/exports to /var/lib/nfs/xtab and pushes
       the resulting export entries into the kernel:

       # exportfs -a

       To export the /usr/tmp directory to host djando, allowing asynchronous writes,  one  would
       do this:

       # exportfs -o async django:/usr/tmp

       Exporting to IP networks, DNS and NIS domains does not enable clients from these groups to
       access NFS immediately; rather, these sorts of exports are hints to mountd(8) to grant any
       mount  requests from these clients.  This is usually not a big problem, because any exist-
       ing mounts are preserved in rmtab across reboots.

       When unexporting a network or domain entry, any current exports to members of  this  group
       will  be  checked  against the remaining valid exports and if they themselves are nolonger
       valid they will be removed.

       exports(5), mountd(8)

       Olaf Kirch, <okir@monad.swb.de>
       Neil Brown, <neilb@cse.unsw.edu.au>

					    7 Sep 1999				      exportfs(8)

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