Mirantis Container Cloud (MCC) becomes part of Mirantis OpenStack for Kubernetes (MOSK)!

Starting with MOSK 25.2, the MOSK documentation set will cover all product layers, including MOSK management (formerly MCC). This means everything you need will be in one place. The separate MCC documentation site will be retired, so please update your bookmarks for continued easy access to the latest content.

Migrate a Ceph Monitor before machine replacement

Available since MCC 2.25.0 (Cluster release 17.0.0)

This document describes how to migrate a Ceph Monitor to another machine on baremetal-based clusters before node replacement as described in Delete a cluster machine using web UI.

Warning

  • Remove the Ceph Monitor role before the machine removal.

  • Make sure that the Ceph cluster always has an odd number of Ceph Monitors.

The procedure of a Ceph Monitor migration assumes that you temporarily move the Ceph Manager/Monitor to a worker machine. After a node replacement, we recommend migrating the Ceph Manager/Monitor to the new manager machine.

To migrate a Ceph Monitor to another machine:

  1. Move the Ceph Manager/Monitor daemon from the affected machine to one of the worker machines as described in Move a Ceph Monitor daemon to another node.

  2. Delete the affected machine as described in Delete a cluster machine.

  3. Add a new manager machine without the Monitor and Manager role as described in Create a machine using CLI.

    Warning

    The addition of a new machine with the Monitor and Manager role breaks the odd number quorum of Ceph Monitors.

  4. Move the previously migrated Ceph Manager/Monitor daemon to the new manager machine as described in Move a Ceph Monitor daemon to another node.