I used ovirt api (POST /ovirt-engine/api/vms/{vm:id}/snapshots) to create several snapshots. When I call the snapshot recovery api (POST /ovirt-engine/api/vms/{vm:id }/snapshots/{snapshot:id}/restore) to  restoe the first snapshot, I found that the next few snapshots were deleted, and it was normal when I restored the last snapshot. Why does the snapshot with the earlier recovery time delete the subsequent snapshot? The vm's os is centos.