[Ceph] Volume backup created with multiple snapshots preventing removal

[Edin S]

The volume backup has multiple snapshots associated with it, which prevents its removal.

Ubuntu 20.04
Openstack Ussuri

Output:
 $ os volume backup show 718ad411-20ce-4f15-a4f6-03ddde5d0ee9
    | fail_reason | Backup should only have one snapshot but instead has 4 |

Volume backup maps to a volume_id of 07bb983c...
   $ os volume backup show 718ad411-20ce-4f15-a4f6-03ddde5d0ee9
<SNIP>
    | volume_id | 07bb983c-0ab4-48ae-822d-890433cf1359 |

Below, we can see that 4 snapshots exist in ceph (for the volume_id 07bb983c-0ab4-48ae-822d-890433cf1359):
    # rbd --pool cinder-ceph snap list cinder-ceph/volume-07bb983c-0ab4-48ae-822d-890433cf1359
    SNAPID NAME SIZE PROTECTED TIMESTAMP
     12935 backup.718ad411-20ce-4f15-a4f6-03ddde5d0ee9.snap.1623724325.88 100 GiB Tue Jun 15 02:32:06 2021
     12936 backup.718ad411-20ce-4f15-a4f6-03ddde5d0ee9.snap.1623724325.92 100 GiB Tue Jun 15 02:32:06 2021
     12941 backup.718ad411-20ce-4f15-a4f6-03ddde5d0ee9.snap.1623724326.09 100 GiB Tue Jun 15 02:32:06 2021
     12944 backup.718ad411-20ce-4f15-a4f6-03ddde5d0ee9.snap.1623724326.11 100 GiB Tue Jun 15 02:32:06 2021

Looking at the timestamps of the snapshots, it looks like it tried creating 4 snapshots at exactly the same time.

Database state for the backup:
    mysql> select id,deleted,deleted_at,status from backups where id in ("718ad411-20ce-4f15-a4f6-03ddde5d0ee9");
    +--------------------------------------+---------+------------+-----------+
    | id | deleted | deleted_at | status |
    +--------------------------------------+---------+------------+-----------+
<SNIP>
    | 718ad411-20ce-4f15-a4f6-03ddde5d0ee9 | 0 | NULL | error |
<SNIP>

I was unable to determine what triggered this issue.

[Sofia Enriquez (lsofia-enriquez)]

Greetings,
Would you mind sharing the next information:
- Steps to reproduce the problem.
- Are you creating incremental backups?
Thanks in advance. Regards