Using the ceph mds fail command

Use the ceph mds fail command to mark an MDS daemon as failed or restart a running MDS daemon.

Before you begin

Before using the ceph mds fail command, make sure that the Ceph MDS daemons are installed and configured.

Marking an MDS daemon as failed: If the daemon was active and a suitable standby daemon was available, and if the standby daemon was active after disabling the standby-replay configuration, using this command forces a failover to the standby daemon. By disabling the standby-replay daemon, this prevents new standby-replay daemons from being assigned.
Restarting a running MDS daemon: If the daemon was active and a suitable standby daemon was available, the "failed" daemon becomes a standby daemon.

For more information about MDS daemons, see:

Fail an MDS daemon.

ceph mds fail MDS_NAME

Replace the MDS_NAME with the name of the standby-replay MDS node.

Note: Use the ceph fs status command to find the Ceph MDS name.

For example:

[ceph: root@host01 /]# ceph mds fail example01