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Can not shrink DPM allocated volume RRS feed

  • Question

  • Hi,

    In DPM 2012 SP1 when I try to shrink the volume its says  "Can't shrink currently due to presence of data towards the end of the volume".

    Also when the recovery points expire , how much is the time or day.

    Thanks


    Friday, May 31, 2013 11:46 AM

Answers

  • Hi,

    DPM calls into Windows API to shrink a recovery point volume.  Windows initiates a Defrag to move files to the beginning of the volume to free up space at the end of the volume so it can be shrunk.  Unfortunately, some files like NTFS metadata and VSS shadow copy files cannot be moved.  In the case of VSS shadow copies, they get deleted when they expire, so they don't need to be moved.  This is why retrying the operation later may work.  PruneShadowCopiesDPM2010.ps1 does the pruning at midnight, so best time to shrink would be right after a prune.

    To see what file cannot be moved and is preventing the shrink, you can look in the Application Event log for events from Defrag.  below are two samples, one for NTFS metadata, and one for a snapshot file.

    Windows 2008 R2 will provide details in the Application event log as seen below.

    Here is an example of a NTFS Metadata file not able to be moved.

    Log Name:      Application
    Source:        Microsoft-Windows-Defrag
    Date:          8/8/2012 5:35:57 PM
    Event ID:      259
    Task Category: None
    Level:         Information
    Keywords:      Classic
    User:          N/A
    Computer:      DPM2012.Contosa.com
    Description:
    A volume shrink analysis was initiated on volume DPM-vol_5119c495-4375-4f3b- (C:\Program Files\Microsoft System Center 2012\DPM\DPM\Volumes\DiffArea\Task Scheduler Writer\vol_5119c495-4375-4f3b-b870-858609d7f15e). This event log entry details information about the last unmovable file that could limit the maximum number of reclaimable bytes.
     
     Diagnostic details:
     - The last unmovable file appears to be: \$BitMap::$DATA
     - The last cluster of the file is: 0xbfffd
     - Shrink potential target (LCN address): 0x2b62f
     - The NTFS file flags are: -S--D
     - Shrink phase: <analysis>
     
     To find more details about this file please use the "fsutil volume querycluster \\?\Volume{309bdece-db4c-11e1-86a0-00155d41d00f} 0xbfffd" command.

    Here is an example of a VSS shadow copy (recovery point) file not able to be moved preventing the shrink. 

    Log Name:      Application
    Source:        Microsoft-Windows-Defrag
    Date:          8/8/2012 5:10:24 PM
    Event ID:      259
    Task Category: None
    Level:         Information
    Keywords:      Classic
    User:          N/A
    Computer:      DPM2012.Contosa.com
    Description:
    A volume shrink analysis was initiated on volume DPM-vol_b1bcbc48-a4d5-4a43- (C:\Program Files\Microsoft System Center 2012\DPM\DPM\Volumes\DiffArea\Non VSS Datasource Writer\vol_b1bcbc48-a4d5-4a43-92f9-2ba619ec29bf). This event log entry details information about the last unmovable file that could limit the maximum number of reclaimable bytes.
     
     Diagnostic details:
     - The last unmovable file appears to be: \System Volume Information\{c439e6e3-cc8f-11e1-82cc-00155d41d00f}{3808876b-c176-4e48-b7ae-04046e6cc752}::$DATA
     - The last cluster of the file is: 0x861ff
     - Shrink potential target (LCN address): 0x2877b
     - The NTFS file flags are: ---AD
     - Shrink phase: <analysis>
     
     To find more details about this file please use the "fsutil volume querycluster \\?\Volume{9b9c6f59-a9f5-11e1-bac6-00155d41d00f} 0x861ff" command.

     

    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.

    Wednesday, June 5, 2013 5:14 PM
    Moderator