DPM 2012 - Long term backup, multiple tapes with single stand-alone drive. RRS feed

  • Question

  • We running DPM 2012 and have one Protection Group configured containing around a dozen servers. The PG is setup for both short-term and long-term protection, ie: we backup to disk each day, which is retained for 90 days, and then we backup to tape once every 3 months, which is taken offsite. The disk backups are working fine although they growing in size quickly rather quickly (currently 8TB). The tape backup worked for 6 months but has started to fail. I we believe is down to insufficient space, ie: too much backup data for a single tape. We are using a single stand-alone HP LTO4 tape drive and manage to squeeze approx. 1TB of backup data onto a tape (using compression). The problem is we aren't receiving any notification to change the tape once its full and the job then fails as I guess it eventually times out.

    Why isn't DPM asking for another tape and/or how to we spread this over multiple tapes using a single stand-alone tape drive? 

    Tuesday, June 4, 2013 12:44 PM

All replies

  • During a tape backup if a tape becomes full and there are no other tapes marked free, Free (contains data) or expired in the library, or if the tape drive is a standalone drive, DPM will raise an alert to prompt for another free tape to continue backup.  The same is true during a restore, if a needed tape is not in the library an alert will be raised.  By Default, DPM It will wait for 1 hour before failing the job.

    This prompting timeout can be configured by the registry entry “PromptingTimeOut” under “HKLM\Software\Microsoft\Microsoft Data Protection Manager\1.0\Prompting”

    PromptingTimeOut:REG_Dword:43200000  (dec) = 12hrs

    The Formula is   (#hrs * 1000 * 60 * 60)
    1HR =  1*1000*60*60 =  3600000  decimal

    So for each hour to wait, multiply by 3600000.
    8hrs = 28800000  decimal

    Restart the DPMRA service.

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    Tuesday, June 4, 2013 3:39 PM