Some 'vm_snapshot_id' fields in the RHEV database contain a zero UUID.

Issue

• The vm_snapshot_id entries in the images tables for some Virtual Machines in the RHEV database contained a zero UUID, e.g.

# psql -U engine -c "select image_guid,image_group_id,vm_snapshot_id from images where image_group_id = '8283094b-096c-4e8f-9421-e96a92b9dd4f';"

              image_guid              |            image_group_id            |            vm_snapshot_id            
--------------------------------------+--------------------------------------+--------------------------------------
 f54ee6b6-40ed-434a-8b29-d88d3e73c19b | 8283094b-096c-4e8f-9421-e96a92b9dd4f | 00000000-0000-0000-0000-000000000000
 33f46948-ff4b-4670-a039-2b0b9c273705 | 8283094b-096c-4e8f-9421-e96a92b9dd4f | 06989ea0-4296-4621-aabe-5609ad65439f

• In some cases, a snapshot_id field in the snapshots table was also zero, e.g.

# psql -U engine -c "select snapshot_id,vm_id from snapshots where vm_id = '3c47241e-87b6-493d-adfb-2abf894ee846';"
             snapshot_id              |                vm_id                 
--------------------------------------+--------------------------------------
 00000000-0000-0000-0000-000000000000 | 3c47241e-87b6-493d-adfb-2abf894ee846
 06989ea0-4296-4621-aabe-5609ad65439f | 3c47241e-87b6-493d-adfb-2abf894ee846

• The symptoms of this condition can vary. One example is shown in this article.