Possible causes for the alert include the following:

• The tape has read/write errors.
  
  
• There is a network failure on the DPM server or protected computer side.
  
  
• Permissions or passwords have changed, and DPM cannot access the folder to back up or recover data.
  
  
• Two tapes have the same bar code but different on-media identifiers (OMIDs).
  
  
• Two tapes have the same OMID but different bar codes.
  
  
• Two tapes have the same OMID, one with a bar code and the other without a bar code.
  
  
• A tape that had been in use by one DPM installation was moved and written to by a different DPM installation and then returned to the original DPM library.
  
  
• Data is corrupt on the tape.
  
  

The error conditions and recommended actions associated with each “Cannot verify tape data” alert are provided in the alert details.

Follow the recommended action in the alert, and retry the job.

• If the tape has read/write errors and you have run a recovery job, look for duplicate tape or an older-point-in-time copy of the same data.
  
  
• Fix the network failure, and rerun the job.
  
  
• Make sure that permissions and passwords are correct so that DPM can access the tape.
  
  
• If two tapes have the same bar code but different OMID, ask the administrator to ensure that each tape has a unique bar code.
  
  
• If two media have the same OMID but different bar codes, it is possible that the administrator switched the bar code on the tape and one tape will be offline. In this case, the two tapes can be labeled the same.
  
  
• If two tapes have the same OMID, one with a bar code and the other without a bar code, ask the administrator to provide a unique bar code for both tapes.
  
  
• The tape has been overwritten. The tape cannot be used.
  
  

Resolved when: The job is rerun and DPM is able to access the tape; two tapes have unique bar codes.

For information about how to manage tape libraries in DPM and verify an unknown tape, in the DPM Operations Guide, see Managing Tape Libraries (http://go.microsoft.com/fwlink/?LinkId=91964).

Concepts