This document is for a development version of Ceph.
ceph-mon – ceph monitor daemon¶
ceph-mon is the cluster monitor daemon for the Ceph distributed file system. One or more instances of ceph-mon form a Paxos part-time parliament cluster that provides extremely reliable and durable storage of cluster membership, configuration, and state.
The mondatapath refers to a directory on a local file system storing
monitor data. It is normally specified via the
mon data option in
the configuration file.
Foreground: do not daemonize after startup (run in foreground). Do not generate a pid file. Useful when run via ceph-run(8).
Debug mode: like
-f, but also send all log output to stderr.
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.
Set gid after starting. If a group name is specified the group record is looked up to get a gid.
Use ceph.conf configuration file instead of the default
/etc/ceph/ceph.confto determine monitor addresses during startup.
mon datadirectory with seed information to form and initial ceph file system or to join an existing monitor cluster. Three pieces of information must be provided:
The cluster fsid. This can come from a monmap (
--monmap <path>) or explicitly via
A list of monitors and their addresses. This list of monitors can come from a monmap (
--monmap <path>), the
mon hostconfiguration value (in ceph.conf or via
-m host1,host2,...), or (for backward compatibility) the deprecated
mon addrlines in ceph.conf. If this monitor is to be part of the initial monitor quorum for a new Ceph cluster, then it must be included in the initial list, matching either the name or address of a monitor in the list. When matching by address, either the
public subnetoptions may be used.
The monitor secret key
mon.. This must be included in the keyring provided via
Specify a keyring for use with
Signal that we don’t want to rely on a ceph.conf, either user provided or the default, to run the daemon. This will entail providing all necessary options to the daemon as arguments.
ceph-mon is part of Ceph, a massively scalable, open-source, distributed storage system. Please refer to the Ceph documentation at https://docs.ceph.com for more information.