When a backup completes successfully while using the Advanced Open File Option (AOFO), information is displayed in the job log. Check the section Backup Set Detail Information in the job log to make sure that AOFO was used during the backup. If the backup included more than one volume, this information is repeated for each volume.
If AOFO fails on initialization, the backup still runs but the job is logged as Completed with Exceptions in the job log.
If AOFO fails during the backup of a device, that backup set is terminated and is reported as an error.
More Information
Setting default options for the Advanced Open File Option
Best practices for using the Symantec Volume Snapshot Provider
About the Symantec Volume Snapshot Provider cache file location