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Consistency check always says replica is inconsistent RRS feed

  • Question

  • We have 3 PGs, containing 1 VM each, same retention period, just different synchronization times (done at night). Looks like generally the backup is working, recovery points are created and status is "OK" for all PGs.

    What makes me feel uncomfortable is that each time I try to run a consistency check on any of the PGs, the replica is reported inconsistent and a full scan is started (lasts several hours).

    Thinking logically: we have a replica, done say 2 ago, we have 2 RPs done at 1:00AM and successfully finished. Consistency check should just checksum them and checksums should be the same.

    BTW: first thought was that problem is caused by MSE running on DPM server. But the settings were configured according to technet article http://technet.microsoft.com/en-us/library/ff399439.aspx and even more restrictive according to this blog http://briandesmond.com/blog/dpm-and-anti-virus-exclusions/. It did not help. Will also try to uninstall antivirus, but think it's smth different.




    Monday, January 2, 2012 7:42 AM

Answers

  • Hi MossImprisoned,

    Consistency Check (CC) is a lengthy operation. It will pretty much compare block by block on what you have on the DPM server to your Production Server.

    If it finds differences, it will transfer the not matching block.

    When a CC is in progress it will always shows "Replica inconsistent, verification in progress"

    Rule of the thumb is: If DPM is not complaining about replica being inconsistent, there is no need for running it.

     

     


    Thanks, Wilson Souza - MSFT This posting is provided "AS IS" with no warranties, and confers no rights
    Monday, January 2, 2012 12:38 PM

All replies

  • Hi MossImprisoned,

    Consistency Check (CC) is a lengthy operation. It will pretty much compare block by block on what you have on the DPM server to your Production Server.

    If it finds differences, it will transfer the not matching block.

    When a CC is in progress it will always shows "Replica inconsistent, verification in progress"

    Rule of the thumb is: If DPM is not complaining about replica being inconsistent, there is no need for running it.

     

     


    Thanks, Wilson Souza - MSFT This posting is provided "AS IS" with no warranties, and confers no rights
    Monday, January 2, 2012 12:38 PM
  • Ok, from you words I understand that consistency check is not actually doing any check, that should answer if you replica is consistent or not.  Instead it does a block-by-block checksuming of the WHOLE data, and will last approximately the same amount of time on replica that is 100% consistent and replica that has 1 wrong byte of data.

    It will report that replica is inconsistent and start the process even on 100%-consistent replica. Sad but true.



    Monday, January 2, 2012 3:55 PM