========================================
 mount.ceph -- mount a ceph file system
========================================

.. program:: mount.ceph

Synopsis
========

| **mount.ceph** *monaddr1*\ [,\ *monaddr2*\ ,...]:/[*subdir*] *dir* [
  -o *options* ]


Description
===========

**mount.ceph** is a simple helper for mounting the Ceph file system on
a Linux host. The only real purpose it serves is to resolve monitor
hostname(s) into IP addresses; the Linux kernel client component does
most of the real work. In fact, it is possible to mount a Ceph file
system without mount.ceph by specifying monitor address(es) by IP::

        mount -t ceph 1.2.3.4:/ mountpoint

Each monitor address monaddr takes the form host[:port]. If the port
is not specified, the Ceph default of 6789 is assumed.

Multiple monitor addresses can be separated by commas. Only one
responsible monitor is needed to successfully mount; the client will
learn about all monitors from any responsive monitor. However, it is a
good idea to specify more than one in case one happens to be down at
the time of mount.

A subdirectory subdir may be specified if a subset of the file system
is to be mounted.


Options
=======

:command:`wsize`
  int, max write size. Default: none (writeback uses smaller of wsize
  and stripe unit)

:command:`rsize`
  int (bytes), max readahead, multiple of 1024, Default: 524288
  (512*1024)

:command:`osdtimeout`
  int (seconds), Default: 60

:command:`osdkeepalivetimeout`
  int, Default: 5

:command:`mount_timeout`
  int (seconds), Default: 60

:command:`osd_idle_ttl`
  int (seconds), Default: 60

:command:`caps_wanted_delay_min`
  int, cap release delay, Default: 5

:command:`caps_wanted_delay_max`
  int, cap release delay, Default: 60

:command:`cap_release_safety`
  int, Default: calculated

:command:`readdir_max_entries`
  int, Default: 1024

:command:`readdir_max_bytes`
  int, Default: 524288 (512*1024)

:command:`write_congestion_kb`
  int (kb), max writeback in flight. scale with available
  memory. Default: calculated from available memory

:command:`snapdirname`
  string, set the name of the hidden snapdir. Default: .snap

:command:`name`
  string, used with authx, Default: guest

:command:`secret`
  string, used with authx

:command:`ip`
  my ip

:command:`noshare`
  create a new client instance, instead of sharing an existing
  instance of a client mounting the same cluster

:command:`dirstat`
  funky `cat dirname` for stats, Default: off

:command:`nodirstat`
  no funky `cat dirname` for stats

:command:`rbytes`
  Report the recursive size of the directory contents for st_size on
  directories.  Default: on

:command:`norbytes`
  Do not report the recursive size of the directory contents for
  st_size on directories.

:command:`nocrc`
  no data crc on writes

:command:`noasyncreaddir`
  no dcache readdir


Examples
========

Mount the full file system::

        mount.ceph monhost:/ /mnt/foo

If there are multiple monitors::

        mount.ceph monhost1,monhost2,monhost3:/ /mnt/foo

If cmon(8) is running on a non-standard port::

        mount.ceph monhost1:7000,monhost2:7000,monhost3:7000:/ /mnt/foo

To mount only part of the namespace::

        mount.ceph monhost1:/some/small/thing /mnt/thing

Assuming mount.ceph(8) is installed properly, it should be
automatically invoked by mount(8) like so::

        mount -t ceph monhost:/ /mnt/foo


Availability
============

**mount.ceph** is part of the Ceph distributed file system. Please
refer to the Ceph wiki at http://ceph.newdream.net/wiki for more
information.

See also
========

:doc:`ceph-fuse <ceph-fuse>`\(8),
:doc:`ceph <ceph>`\(8)