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 back ends.

To define Ceph pools for Cinder multiple back ends:

  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 back-end 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 back end and registered as a new volume type, which you can use to create Cinder volumes.