Description of problem:

OpenStack Manila has support for "managing" and "unmanaging" shares and share snapshots, a valuable workflow for cloud administrators to take shared file systems (and their snapshots) in and out of manila's management. Managing allows manila to adopt/import a share into a configured backend storage system, and apply manila specific extra specifications on it.

Consider for instance a possibility of moving a ceph cluster across OpenStack deployments; or rebuilding an existing OpenStack deployment and registering shares back. It's not trivial for an administrator to remove a share from manila or restore it into manila when performing these day2 cluster maintenance operations. Manila also doesn't support retype operations currently. The alternative to retyping is to migrate shares (which involves an expensive data copy) or to un-manage and re-manage them with a different share type.

Version-Release number of selected component (if applicable): 17

Additional info: The upstream blueprint for this feature is: https://blueprints.launchpad.net/manila/+spec/manage-unmanage-cephfs-shares-and-snapshots