Learn the UNIX/Linux command line
Home Man Pages
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 permit-
ted 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 infor-
mation 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
reason 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.
-V or --nfs-version
This option can be used to request that rpc.mountd offer cer-
tain 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).
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)
UNIX/Linux commands referenced on this page: