From PR https://github.com/ManageIQ/manageiq/pull/13218: Introduced by https://github.com/ManageIQ/manageiq/pull/12551 get_checked_volume_id(params) was changed in https://github.com/ManageIQ/manageiq/pull/12845 and https://github.com/ManageIQ/manageiq/pull/12859 to checked_item_id. Before: Attach and Detach didn't work for Cloud Volume. Ended with error unknown method get_checked_volume_id After: Attach and Detach works for Cloud Volume.