--- upgrade: - To get rid of long running DB data migrations that must be run offline, Cinder will now be able to execute them online, on a live cloud. Before upgrading from Ocata to Pike, operator needs to perform all the Newton data migrations. To achieve that he needs to perform ``cinder-manage db online_data_migrations`` until there are no records to be updated. To limit DB performance impact migrations can be performed in chunks limited by ``--max_number`` option. If your intent is to upgrade Cinder in a non-live manner, you can use ``--ignore_state`` option safely. Please note that finishing all the Newton data migrations will be enforced by the first schema migration in Pike, so you won't be able to upgrade to Pike without that.