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Cant shrink custom DPM Recovery Point volume RRS feed

  • Question

  • Hello all,

    I am stuck with a frustrating problem. We are running DPM 2010 Final on a Windows 2008 Server box. We have a vary large Recovery point and Replica volume. The replica is 15TB and the Recovery Point is 6TB however we are only using 1TB of the Recovery Point after 3 years. We want to shrink the recovery point. We go into diskmgmt.msc and try to change it but it says there is zero kb that can be reclaimed. If we do it at the command line (diskpart -> select volume -> shrink) it gives the error "The specified shrink size is too large."

    We understand that this issue is often the result of there being immovable files such as the $MFT on the parameter of the space as outlined well here (http://www.howtogeek.com/howto/windows-vista/working-around-windows-vistas-shrink-volume-inadequacy-problems/). We have attempted to move these so called immovable files with PerfectDisk 11 which did show that the MFT had been moved from the back of the volume to the middle but we are still getting the same errors on shrink.

    So my questions are this

    Does anyone have any idea on how to get this volume to shrink?

    Would it be possible to convert the volume to a basic disk, shrink it and then convert back to a dynamic without destroying the recovery points?

    Does the LVM in Windows 2008 R2 solve this problem?

    Is there anyway to by hand move the immovable files?

    This option I do not like at all but could use MigrateDatasourceDataFromDPM to migrate the recovery points to a smaller volume?

    Lastly is there anything that can be done to avoid this in the future?

     

    Thanks for all your assistance!

    Thursday, August 26, 2010 7:47 PM

Answers

  • Hi,

    For the recovery point volume, VSS makes snapshot files and those file are pinned and nothing can move them. 

    When you used diskpart - did you use the shrink querymax switch ?

    IE:
    DISKPART> sel vol 2

    Volume 2 is the selected volume.

    DISKPART> shrink querymax

    The maximum number of reclaimable bytes is:   23 GB (24123 MB)

    DISKPART> Shrink DESIRED=24000

    As old recovery points expire, the pinned file will get deleted, so over time, you should be able to shrink it little by little. 

    You can manually run the DPM powershell command pruneshadowcopies2010.ps1 and after it completes, try running diskpart again and try the shrink command for the maximum size allowed.

     

     

     


    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Thursday, August 26, 2010 11:48 PM

All replies

  • Hi,

    For the recovery point volume, VSS makes snapshot files and those file are pinned and nothing can move them. 

    When you used diskpart - did you use the shrink querymax switch ?

    IE:
    DISKPART> sel vol 2

    Volume 2 is the selected volume.

    DISKPART> shrink querymax

    The maximum number of reclaimable bytes is:   23 GB (24123 MB)

    DISKPART> Shrink DESIRED=24000

    As old recovery points expire, the pinned file will get deleted, so over time, you should be able to shrink it little by little. 

    You can manually run the DPM powershell command pruneshadowcopies2010.ps1 and after it completes, try running diskpart again and try the shrink command for the maximum size allowed.

     

     

     


    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Thursday, August 26, 2010 11:48 PM
  • Hi.

    Is there any way to shrink with a powershell script instead of pushing the "shrink"-button in DPM?

    We have a lot of database backup that changes in size.

    DPM2010 is basically powershell with a GUI, it must be a way to do this.

     

    I tested the script

    http://blogs.technet.com/b/dpm/archive/2010/03/31/how-much-can-i-shrink-recovery-point-volumes-with-dpm2010.aspx

    and that worked fine. But instead of showing i need action...

    Does the "shrink"-button actually do somethin like:

    $objekt_specified_by_DPM DISKPART  shrink desired=$amount_possible_to_shrink

    I know this is not an actual command but you get the idea.

     

    /Karl Berglind

     

    Wednesday, November 3, 2010 3:47 PM