Remove a Host From a Rook Ceph Cluster

Note

The hosts must be deleted one by one, perform the complete operation on each host before proceeding to the next.

Warning

Before removing a host, verify whether it is running a monitor. Ensure that its removal will not break the Ceph monitor quorum. If removing the target host would reduce the number of monitors below the quorum threshold, deploy a new monitor on a different host first. Only proceed with the deletion once the new monitor is fully integrated and the cluster has re-established quorum.

For more information on Ceph monitor quorum see Adding/Removing Monitors.

Remove an Online Host

Before deleting a host that runs Ceph components such as OSDs, or monitors, you must first remove those components from the host via the Rook Ceph cluster configuration.

After removing the components from the host-fs, reapply the Rook Ceph to finalize the operation.

# For hosts without OSDs:
$ system host-fs-modify <host> ceph --functions=

# For hosts with OSDs:
$ system host-fs-modify <host> ceph --functions=osd

# Reapply the application
$ system application-apply rook-ceph

For more information on how to delete monitors, see Remove a monitor.

To remove all OSDs, obtain the UUID of the OSDs, mark them for removal, then reapply the Rook Ceph.

# Get the UUID of the OSD
$ system host-stor-list <host>

# Mark each OSDs for deletion
$ system host-stor-delete <uuid>

# Reapply the application
$ system application-apply rook-ceph

For more information on how to delete OSDs, see Remove OSDs.

After removing the monitor and all OSDs and reapplying the Rook Ceph, the host-fs ceph resource should transition to the ‘Ready’ state. Once in this state, the host can be safely deleted.

$ system host-lock <host>
$ system host-delete <host>

Remove an Offline Host

If a host is in an unrecoverable state and cannot be brought back online, the host-fs must be forcefully deleted.

Mark all associated Ceph components — including monitors and OSDs — for deletion in the Rook Ceph configuration. Once all components are marked and removed, force delete the host-fs ceph.

$ system host-fs-delete <host> ceph --force

Reapply the Rook Ceph application to allow the cluster to reconcile and finalize the operation.

$ system application-apply rook-ceph

After removing the monitor and all OSDs from the host and reapplying the Rook Ceph application, the host-fs ceph should transition to the ‘Ready’ state. Once in this state, the host can be safely deleted.

$ system host-lock <host>
$ system host-delete <host>