none
DPM and Access Databases not recovering all records RRS feed

  • Question

  • I have recently had to recover a Microsoft Access Database using Data Protection Manager version 4.2.1553.0.  Where this particular database is located, get backed up nightly.  I had a user complain that the restore file was missing over 500 records.  This is not the first time this has happened with several of my access databases being backed up using DPM.  I have gone back 9 days in recovery and am still missing the 500 newly added records.  Can someone explain to me why this is happening.

    Thanks

    Cheston

    Monday, November 14, 2016 10:09 PM

All replies

  • Hi,

    We have seen some 3rd party antivirus drivers can mask IO changes to access database files.  These are two Anti-virus drivers that are known to cause the problem.  

    1)  AVG
    Anti-virus software AvgMfx64.sys driver

    2)  McAfee Ant-Virus software
    MFEHIDK.SYS driver

    Since there are no errors associated with this problem, and the only visual indication is lack of data being transferred during synchronization / express full jobs for that data source, there is no easy way to discover this problem in the DPM Console unless you looking at data transferred on a regular basis. However, you can proactively discover this condition if you use a DPM power shell command to run a manual recovery point with integrity check. This job will perform a normal synchronization, followed by an integrity check to ensure data on protected server and data on DPM replica match block for block. If it finds any mismatch, it fixes the replica for the same and it raises the alert that corruption has been detected.

    To run a synchronization with integrity check see the following TechNet article:

    New-RecoveryPoint with Integritycheck
    http://technet.microsoft.com/en-us/library/cc627335.aspx

    If you cannot change your AV software, You can instruct DPM not to use the dpmfilter and instead use CC workflow to detect changes by adding the forcefixup key on the Protected server.


    Open an administrative command prompt on the effected Protected Server(s).

    - Stop the DPMRA:
        Net stop dpmra
    - Unload the dpmfilter:
        Fltmc unload dpmfilter
    - Set the Force Fixup Registry key
    - Run the following command from an administrative command prompt on the protected servers(s):

         Reg add "HKLM\SOFTWARE\Microsoft\Microsoft Data Protection Manager\Agent\2.0" /v ForceFixup /t REG_DWORD /d 1

    NOTE: Synchronizations and express full Recovery points may take up to 3 times longer (or more) to finish when forcefixup key is added.


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.

    Tuesday, November 15, 2016 4:41 PM
    Moderator
  • DPM doesn't do anything special about Access files, it simply does a backup of the file. So you get a point in time backup of that file. If stuff is missing, it probably was never written to the file.
    Friday, November 18, 2016 2:34 PM