Comment 5 for bug 1662352

The volume can not be deleted is due to some other volume is dependent on the volume2.
The workaround for this issue is:
1. If the the users do not care about the flash copies, they can force delete this volumes in the backend storage.
2. If users really want the flash copies to complete, they can do the delete operation sometime later. Since the flash copy relationship will be deleted automatically after data copy finished.

Gerald, we can not set wait_for_copy to true directly if len(mapping_ids) > 1, since there is also snapshot cases. The copy_rate for snapshot is 0, we still need to change the copyrate and set autodelete. What we should check the vdisk dependency relationship.