Exchange VSS Writer has processed the backup completion event for a backup which did not involve any Exchange components. ...

Exchange VSS Writer has processed the backup completion event for a backup which did not involve any Exchange components. Due to limitations in the implementation of the backup completion event, it is not possible to retrieve the instance identifier of the backup set at this phase of the backup process when no Exchange components are involved. Therefore, cleanup of certain resources associated with this backup will be deferred to the backup shutdown event (at which point the instance identifier for the backup set will be available).