=========================================
 ceph-mds -- ceph metadata server daemon
=========================================

.. program:: ceph-mds

Synopsis
========

| **ceph-mds** -i *name* [[ --hot-standby [*rank*] ]|[--journal_check *rank*]]


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

**ceph-mds** is the metadata server daemon for the Ceph distributed file
system. One or more instances of ceph-mds collectively manage the file
system namespace, coordinating access to the shared OSD cluster.

Each ceph-mds daemon instance should have a unique name. The name is used
to identify daemon instances in the ceph.conf.

Once the daemon has started, the monitor cluster will normally assign
it a logical rank, or put it in a standby pool to take over for
another daemon that crashes. Some of the specified options can cause
other behaviors.

If you specify hot-standby or journal-check, you must either specify
the rank on the command line, or specify one of the
mds_standby_for_[rank|name] parameters in the config.  The command
line specification overrides the config, and specifying the rank
overrides specifying the name.


Options
=======

.. option:: -f, --foreground

   Foreground: do not daemonize after startup (run in foreground). Do
   not generate a pid file. Useful when run via :doc:`ceph-run
   <ceph-run>`\(8).

.. option:: -d

   Debug mode: like ``-f``, but also send all log output to stderr.

.. option:: -c ceph.conf, --conf=ceph.conf

   Use *ceph.conf* configuration file instead of the default
   ``/etc/ceph/ceph.conf`` to determine monitor addresses during
   startup.

.. option:: -m monaddress[:port]

   Connect to specified monitor (instead of looking through
   ``ceph.conf``).

.. option:: --journal-check <rank>

    Attempt to replay the journal for MDS <rank>, then exit.

.. option:: --hot-standby <rank>

    Start as a hot standby for MDS <rank>.

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

**ceph-mds** is part of Ceph, a massively scalable, open-source, distributed storage system. Please refer to the Ceph documentation at
http://ceph.com/docs for more information.


See also
========

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