Current Running environment is ESX 4.1 and Veeam 5 (running on a VM) for backups.
The current backup job never completed successfully, it simply stopped mid backup. I couldn't kill the job or do anything so I rebooted the Veeam backup server.
To finish the clean up I selected the VM that was being processed in the stuck backup and told the system to remove the snapshot.
An error message was received and the snapshot was never removed. The error message was "unable to access file since it is locked"