Quiesce operations and SQL backups
This is not really a VMware issue, however, we hit it when using vSphere Replication, because VR uses VSS Quiesce.
In this case, the customer was using Symantec to backup his SQL database, the database itself mind, not the VM, this is important.
When Symantec backups up the DB, it adds an entry in the /backupset/ table, marking the last backup timestamp, the next time it tries to backup, if compares what it has with the records in that table, if they match, go ahead, if not, errors and doom.
What does that have to do with anything I hear you ask.
Well, it turns out, that a VSS Quiesce operation will also update this table, so ANYTHING relying on VSS will trigger this, snapshots, VR VSS Quiesce, NTBackup…etc.
Like I said, not really a VMware issue.
The fix? Well you can ask Microsoft, I don't know how to tell VSS not to update the DB, that is beyond me, but I did find two Microsoft KBs that describe the issue.
Fix? What fix?