Ceph pools for Cinder multi-backend

Available since MOSK 23.2

The KaaSCephCluster object supports multiple Ceph pools with the volumes role to configure Cinder multiple backends.

To define Ceph pools for Cinder multiple backends:

  1. In the KaaSCephCluster object, add the desired number of Ceph pools to the pools section with the volumes role:

    kubectl -n <MOSKClusterProject> edit kaascephcluster

    Substitute <MOSKClusterProject> with corresponding namespace of the MOSK cluster.

    Example configuration:

    spec:
  cephClusterSpec:
    pools:
    - default: false
      deviceClass: hdd
      name: volumes
      replicated:
        size: 3
      role: volumes
    - default: false
      deviceClass: hdd
      name: volumes-backend-1
      replicated:
        size: 3
      role: volumes
    - default: false
      deviceClass: hdd
      name: volumes-backend-2
      replicated:
        size: 3
      role: volumes

  2. Verify that Cinder backend pools are created and ready:

    kubectl -n <managedClusterProject> get kaascephcluster -o yaml

    Example output:

    status:
  fullClusterStatus:
    blockStorageStatus:
      poolsStatus:
        volumes-hdd:
          present: true
          status:
            observedGeneration: 1
            phase: Ready
        volumes-backend-1-hdd:
          present: true
          status:
            observedGeneration: 1
            phase: Ready
        volumes-backend-2-hdd:
          present: true
          status:
            observedGeneration: 1
            phase: Ready

  3. Verify that the added Ceph pools are accessible from the Cinder service. For example:

    kubectl -n openstack exec -it cinder-volume-0 -- rbd ls -p volumes-backend-1-hdd -n client.cinder
kubectl -n openstack exec -it cinder-volume-0 -- rbd ls -p volumes-backend-2-hdd -n client.cinder

After the Ceph pool becomes available, it is automatically specified as an additional Cinder backend and registered as a new volume type, which you can use to create Cinder volumes.