Backup operations for VMware create virtual machine snapshots. When the backup of a VM completes, the backup process removes the VM snapshot immediately. Also, the backup process checks the virtual machine state to verify that delta disks have been consolidated back into the parent virtual disk.
Every snapshot that is created is also registered with the CommServe system to ensure that all snapshots are properly cleaned up. If a snapshot is not removed when a backup completes, the registration with the CommServe system remains. The CommServe system periodically attempts to remove the snapshot, and continues to monitor the consolidation status until the snapshot is successfully removed.
If a new backup starts for a virtual machine and a pre-existing backup snapshot exists, then the old snapshot is removed and consolidated before a new backup snapshot is created.