Scheduled Backups May Hang After Mounting Tape

When Windows 2000 Backup (Ntbackup.exe) is scheduled to run at a later time and you choose to overwrite the existing tape media by using the /um switch, the backup never completes. When you look at Scheduled Tasks, the jobs status reports it is still running, and Task Manager still shows Ntbackup.exe on the Processes tab. If you view the work queue under Removable Storage Manager (RSM), the last item that is listed is a MOUNT operation by Backup. Also, if you start another interactive backup session and look at the backup report for the scheduled backup job, it is totally blank.

The tape that was mounted contains a media label that was written by a third-party program that uses a proprietary media label type. A proprietary media label type is a non-Microsoft Tape Format (MTF) label. The Windows 2000 Backup program is waiting for a response to the following message: Because the Windows 2000 backup job was scheduled and is running in the background, this question cannot be answered by a user, and this prevents Backup from continuing.

NOTE: The /um switch was designed to only overwrite tapes that contain an MTF label, Free Media label, or tapes that do not contain a label (unrecognized). This allows you to share the tape drive with other third-party programs that use their own media label type without worrying that they will be accidentally be overwritten by Windows 2000 Backup.

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

IMPORTANT: Before you proceed, you must use Task Manager to end all instances of Ntbackup.exe that may be running on the Processes tab. After the Ntbackup.exe process is ended, use RSM to manually dismount the tape that was left in the tape drive from the canceled backup. This allows the tape drive to be used by other programs including future backup jobs.

If you want to use other program's tapes that contain a non-MTF label with a scheduled Windows 2000 backup job, you will first need to use RSM to deallocate the tapes from the program that owns them, and then prepare those tapes. This writes a new "free media label" to the tape and allow unattended backups to use them without generating prompts. To deallocate and prepare media in RSM:

1. Insert the media into the tape drive that you want to deallocate and prepare.
2. In Computer Management, expand Storage, expand Removable Media, and then expand Physical Locations.
3. Locate the entry for the tape device, right-click the device, and then click Inventory.
4. After the inventory completes, click the Media icon under the tape device. The tape media is displayed in the right pane.
5. Right-click the media you want to deallocate, point to All Tasks, and then click Deallocate.
6. When you receive the following prompts, click Yes at each prompt:
   • Confirm Media Deallocation
     Deallocating media without the knowledge of the owning application can cause the data on it to be lost.
     Are you sure you want to deallocate the selected item ?
     
     YES NO
   • Confirm Media Deallocation
     Are you sure you want to deallocate 'tape_name'?
     
     YES NO
7. Right-Click the media you just deallocated, and then click Prepare.
8. When you receive the following prompts, click Yes at each prompt:
   • Confirm Media Preparation
     This operation will destroy the data on the media and move it to the free media pool.
     
     Are you sure to write a free media label on the selected medium ?
     
     YES NO
   • Confirm Media Preparation
     Are you sure you want to write a free media label on 'tape_name'?
     
     YES NO
9. After being prepared, this piece of media is now ready to be used for scheduled backups.
10. If you want to prepare more media, use the Eject Wizard to eject the freshly-prepared media, and then repeat this procedure for each piece of media you want to prepare.

If the third-party program that uses their own media label type is no longer used and was removed or un-installed, it may leave a Media Label Library (MLL) registered with RSM. If you would like RSM to automatically move this program's media to the "unrecognized" media pool so scheduled backups can use it without having to prepare it ahead of time, use the following procedure to unregister the unused OEM Media Label Library (MLL) entry:

1. Start Regedt32.exe, and view the following registry key:
   HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\NTMS\OMID\Tape
2. Under the TAPE key, there should be three additional default keys:
   
   
   • HP
   • MTF
   • QIC
   
   Remove the key that is associated with the uninstalled OEM program, and leave the preceding keys intact. For example, ARCServ uses the key that is named ARC, and registers the file Mll_arc.dll.
3. Quit Regedt32.exe.
4. At a command prompt, type NET STOP "REMOVABLE STORAGE", press ENTER, type NET START "REMOVABLE STORAGE", and then press ENTER. This restarts RSM without the registered OEM MLL and allows backup to use the tapes with the non-MFT label type. This is because the media now appears as "unrecognized" to RSM and the scheduled backup will overwrite it without prompting when you use the /um switch.

For additional information about media recognition, click the article number below to view the article in the Microsoft Knowledge Base: