Comment 0 for bug 1727184

If you have an existing deployment with ceph-client relation directly between cinder and ceph-mon and wish to switch to making use of cinder-ceph subordinate there is currently no upgrade path.

Existing volumes will be in the 'ceph' pool while cinder-ceph will configure cinder-volume to use 'cinder-ceph' pool.

Users are required to use cinder-ceph subordinate for the ceph-client relation to enable ceph-access relation between cinder-ceph and nova-compute. The latter is required for Nova volume operations to work correctly starting OpenStack Ocata.

There should be a upgrade path.