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Server crashed, now missing volume RRS feed

  • Question

  • Can someone point me in the right direction? We had our DPM server crash. It has rebooted fine and all else is functioning fine however 1 member of the protection group says "Volume missing"

    Peaking at Disk Management it looks like the volume might be hosed.

    What is the best plan of action here?

    Thanks in advance.

    Friday, June 12, 2015 3:23 PM

Answers

  • Hi,

    Unfortunately, this volsnap error says it all, and in my experience VSS metadata corruption is not really recoverable.

    Source volsnap EventID 82

    Volume \\?\Volume{736c20a9-c999-11e3-93fe-00155d0a1204} is offline for shadow copy protection.  A shadow copy meta data corruption was detected.  Please try clearing the protection fault or restart the computer.  If all else fails, revert out of shadow copy protection mode to reclaim the use of the volume while losing the shadow copies.

    The easiest and quickest solution is to stop protection and delete the replica then re-protect so new volumes get created and new VSS snapshots can be created. However, with a volume that size I can see where that would not be a desirable solution, so you can call support and they can run a special version of vshadow.exe utility to reset shadow copy protection mode without having to delete the replica.


    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.

    Friday, June 12, 2015 5:56 PM
    Moderator

All replies

  • Hi,

    1 - Try assigning a drive letter to the volume and then run chkdsk against it and see what it says.

    2 - Look in the System Event log for events from VOLSNAP and see if that volume is in shadow copy protection mode.


    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.

    Friday, June 12, 2015 4:17 PM
    Moderator
  • 1 - 

    I get this response 

    The type of the file system is RAW.
    CHKDSK is not available for RAW drives.

    2- 

    I have 3 volsnap erroers

    2 at time of crash 1 from a reboot this morning.

    Source volsnap EventID 82

    Volume \\?\Volume{736c20a9-c999-11e3-93fe-00155d0a1204} is offline for shadow copy protection.  A shadow copy meta data corruption was detected.  Please try clearing the protection fault or restart the computer.  If all else fails, revert out of shadow copy protection mode to reclaim the use of the volume while losing the shadow copies.

    Ideas from here?



    • Edited by JustusIV Friday, June 12, 2015 5:38 PM
    Friday, June 12, 2015 5:22 PM
  • Googling around i found this article

    http://blogs.technet.com/b/dpm/archive/2011/12/13/troubleshooting-dpm-volumes-are-flagged-as-missing-and-volsnap-logs-event-id-86.aspx

    at the end it says this

    If any of the volumes are showing up in Disk Manager as "Raw" you will need to bring them out of Shadow Copy Protection mode using vshadow-x64.exe

    Trying to decide what to do at this point.

    Thanks

    Friday, June 12, 2015 5:42 PM
  • Hi,

    Unfortunately, this volsnap error says it all, and in my experience VSS metadata corruption is not really recoverable.

    Source volsnap EventID 82

    Volume \\?\Volume{736c20a9-c999-11e3-93fe-00155d0a1204} is offline for shadow copy protection.  A shadow copy meta data corruption was detected.  Please try clearing the protection fault or restart the computer.  If all else fails, revert out of shadow copy protection mode to reclaim the use of the volume while losing the shadow copies.

    The easiest and quickest solution is to stop protection and delete the replica then re-protect so new volumes get created and new VSS snapshots can be created. However, with a volume that size I can see where that would not be a desirable solution, so you can call support and they can run a special version of vshadow.exe utility to reset shadow copy protection mode without having to delete the replica.


    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.

    Friday, June 12, 2015 5:56 PM
    Moderator
  • Its a bummer for sure but not the end of the world.

    Will i lose the Recovery points, when recreating the protection?


    • Edited by JustusIV Friday, June 12, 2015 5:59 PM
    Friday, June 12, 2015 5:58 PM
  • Hi,

    Yes, when you stop protection and delete the replica you will loose the snapshots, but they are already unrecoverable so you really have little choice. 


    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.

    Friday, June 12, 2015 6:02 PM
    Moderator
  • Thank you for your advice. that will be my plan of action.

    Friday, June 12, 2015 6:02 PM
  • If you could maybe explain a bit why I have lost my recovery points, when the Volume labeled Reovery Point Volume is still intact?

    Why losing the Replica Volume causes me to lose everything?

    Just for my own understanding.


    • Edited by JustusIV Friday, June 12, 2015 6:11 PM
    Friday, June 12, 2015 6:11 PM
  • Hi,

    There are two volumes for every protected data source.  The replica holds the protected data and the recovery point volume hold VSS shadow copies for recovery points.  Under normal circumstances, before a block of data is overwritten on the replica, that block is first copied to the recovery point volume (this is called copy-on-write COW) and stored in the active snapshot.   VSS maintains metadata about the snapshot files associated with the replica.  If the active snapshot cannot be maintained (IE: metadata corruption, or missing recovery point volume etc.) then VSS takes the replica volume offline for shadow copy protection so no new blocks can be written. If new writes were allowed without being able to perform a COW the previous shadow copies would be invalidated and would have to be deleted.    So, basically, you cannot write to the replica because it is in an offline (RAW) state and cannot be brought back online because of the VSS metadata corruption.   Recovery points are only valid if the replica volume is readable.  VSS snapshots are of no use without the matching replica volume for which the snapshots were taken for.


    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.

    Friday, June 12, 2015 6:28 PM
    Moderator
  • Thank you for this
    Friday, June 12, 2015 6:29 PM