In the backup, AdvancedCopy Manager automatically selects a device which has the same capacity as the target transaction volume as a backup volume from a group of registered devices.
If a backup volume in the tracking state exists when AdvancedCopy Manager looks for a backup volume for the snapshot high-speed backup, it selects the backup volume in the tracking state in preference to any other and uses it as the backup destination.
When it is necessary to recognize a specific backup destination device for any reason a "device map file" that defines the relationship between a transaction volume and backup volume must be created in advance. By specifying the "device map file" when starting the backup, the backup can always be performed because the backup destination has already been specified.
Point
If multiple generations are to be managed, multiple device map files must be prepared.