Comment 0 for bug 1801316

The backup file failed to be deleted because the backup driver configured on the same storage backend is different.
You can reproduce the problem by following the steps below.

1.Config the "backup_driver=cinder.backup.drivers.ceph.CephBackupDriver" in cinder.conf, and then create a backup from a available/in-use volume, backup name is "vol_backup01";
2.Change the "backup_driver=cinder.backup.drivers.ceph", and then to delete the backup with "vol_backup01", there will be throw an exception (under below).

Hint: You can also change the order of setting backup_driver in steps 1 and 2 to test, and the same problem will occur.
This is the same storage backend. It is unreasonable that the delete operation cannot be performed just because the backup_driver is different.

2018-11-02 10:05:28.088 7 ERROR oslo_messaging.rpc.server Traceback (most recent call last):
2018-11-02 10:05:28.088 7 ERROR oslo_messaging.rpc.server File "/var/lib/kolla/venv/lib/python2.7/site-packages/oslo_messaging/rpc/server.py", line 163, in _process_incoming
2018-11-02 10:05:28.088 7 ERROR oslo_messaging.rpc.server res = self.dispatcher.dispatch(message)
2018-11-02 10:05:28.088 7 ERROR oslo_messaging.rpc.server File "/var/lib/kolla/venv/lib/python2.7/site-packages/oslo_messaging/rpc/dispatcher.py", line 265, in dispatch
2018-11-02 10:05:28.088 7 ERROR oslo_messaging.rpc.server return self._do_dispatch(endpoint, method, ctxt, args)
2018-11-02 10:05:28.088 7 ERROR oslo_messaging.rpc.server File "/var/lib/kolla/venv/lib/python2.7/site-packages/oslo_messaging/rpc/dispatcher.py", line 194, in _do_dispatch
2018-11-02 10:05:28.088 7 ERROR oslo_messaging.rpc.server result = func(ctxt, **new_args)
2018-11-02 10:05:28.088 7 ERROR oslo_messaging.rpc.server File "/var/lib/kolla/venv/lib/python2.7/site-packages/cinder/backup/manager.py", line 756, in delete_backup
2018-11-02 10:05:28.088 7 ERROR oslo_messaging.rpc.server raise exception.InvalidBackup(reason=err)
2018-11-02 10:05:28.088 7 ERROR oslo_messaging.rpc.server InvalidBackup: Invalid backup: Delete backup aborted, the backup service currently configured [cinder.backup.drivers.ceph] is not the backup service that was used to create this backup [cinder.backup.drivers.ceph.CephBackupDriver].