Scenario:
- You have only one virtual tape library configured.
 - Normally, all backups go to the local RAID array. It means that the tape library normally contains only the tapes located on the RAID array.
 - Once a month, you connect an external HDD.
 - Your script detects the newly connected drive, loads tapes from it, initiates a full backup, and when the backup finishes, reloads tapes from the RAID array.
 - You disconnect the external HDD until the next month.
 
- Detects that an external HDD for a monthly backup is connected (for example, by checking if MonthlyBackup.fsmap exists on the drive).
 - If necessary, deletes expired tapes from the external HDD and creates new tapes.
 - Saves the current media layout (i.e. the list of currently loaded RAID tapes) to a temporary file.
 - Unloads all current tapes and loads new tapes from the external HDD.
 - Initiates a full backup in DPM and waits for the backup to finish.
 - Unloads all current tapes and loads the saved media layout.