Tuesday, June 30, 2009

I/O device errors during tape backup

My experience is that tape drive errors are common with many backup applications. DPM is no difference here. According to posts I found most issues are caused due to incorrect behavior either by tape drive firmware or device driver.

But I found also some issues where DPM fails to span to multiple tapes. This could be solved by creating a registry key: [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft Data Protection Manager\Agent] "BufferQueueSize"=dword:00000001" This will ensure that backup will span to next available whenever any IO device error beyond of 30 GB on tape occurs. There by avoiding backup failures


  1. These guys do a good job of helping seniors with data backups: http://modernseniortech.com/computerservices/backupservices.html

  2. It seems that this fix often times breaks your ability to "read recoverable items" from a tape that has been pruned from the DPM database. Keeps this in mind if you need to apply this fix. You will need to change it back or the recatalog operation will time out after 24 hours.

    See here: