CEPH-MDS(8) Ceph CEPH-MDS(8)

# [NAME](#NAME)

ceph-mds - ceph metadata server daemon

# [SYNOPSIS](#SYNOPSIS)

```
ceph-mds -i <ID> [flags]
```

# [DESCRIPTION](#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.

# [OPTIONS](#OPTIONS)

[**-f, --foreground**](#f,)

Foreground: do not daemonize after startup (run in foreground). Do not generate a pid file. Useful when run via ceph-run &lt;&gt;(8).

[**-d**](#d)

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

[**--setuser userorgid**](#setuser)

Set uid after starting. If a username is specified, the user record is looked up to get a uid and a gid, and the gid is also set as well, unless --setgroup is also specified.

[**--setgroup grouporgid**](#setgroup)

Set gid after starting. If a group name is specified the group record is looked up to get a gid.

[**-c ceph.conf, --conf=ceph.conf**](#c)

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

[**-m monaddress\[:port\]**](#m)

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

[**--id/-i ID**](#id/)

Set ID portion of the MDS name. The ID should not start with a numeric digit.

[**--name/-n TYPE.ID**](#name/)

Set the MDS name of the format TYPE.ID. The TYPE is obviously 'mds'. The ID should not start with a numeric digit.

# [AVAILABILITY](#AVAILABILITY)

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

# [SEE ALSO](#SEE_ALSO)

ceph &lt;&gt;(8), ceph-mon &lt;&gt;(8), ceph-osd &lt;&gt;(8)

# [Copyright](#Copyright)

2010-2014, Inktank Storage, Inc. and contributors. Licensed under Creative Commons Attribution Share Alike 3.0 (CC-BY-SA-3.0)

September 24, 2026 dev

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Document: ceph-mds(8) from ceph-20 20.2.4-r4 (Chainguard OS)
Source: https://github.com/ceph/ceph.git