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Cannot delete Checkpoint after manually merging avhdx-files RRS feed

  • Question

  • Hello!

    we had a problem with our backup-software. There have been created checkpoints every day but haven't deleted after the backup.
    I merged the avhdx files until only a vhdx-disk has been left with the following powershell command:

    merge-vhd -Path FS1_F6BECDB6-FE79-4A43-A550-7F5FD563A062.avhdx -DestinationPath FS1_FFA1D4D5-033F-4E3C-ACB4-222CBFBCE14D.avhdx

    This works all find. Then I chanced the disks at the fail-over-manager from the avhdx-files to the vhdx.files. The server now runs without any problems.

    BUT!! in the Hyper-V-manager the old checkpoint are still visble and I'm not able to delete them with the following message:
    The operation failed because the file was not found.
    That message is write - all the avhdx-files have been deleted.

    How do I manage to delete these old - no longer existing - checkpoints? As long as they exist the backup-software will not create new ones and we don't have a backup :(

    I hope someone can help me to solve this problem.

    Thank you in advance

    Michael

    Tuesday, July 17, 2018 12:47 PM

All replies

  • Hi ,

    >>we had a problem with our backup-software. There have been created checkpoints every day but haven't deleted after the backup.

    What backup software did you use? Windows server backup or third-party backup tool?

    Also, you might try the following PowerShell command :

    Get-VM -name | remove-vmsnapshot

    Warning this will remove all snapshots.

    Best Regards,

    Candy


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    • Proposed as answer by sergeyshadow Tuesday, November 20, 2018 7:16 PM
    Wednesday, July 18, 2018 2:57 AM
  • Hello!

    we are using a third party backup tool (NovaStor).

    When run the following command nothing happens:

    PS C:\Windows\system32> Get-VM -name RZMAIL2 | remove-vmsnapshot
    PS C:\Windows\system32>

    No errors but the Checkpoints / Snapshots still there :(

    Best regards

    Michael

    Wednesday, July 18, 2018 8:55 AM
  • Hi Michael,

    Thanks for your updating.

    I would suspect the backup software. Since the checkpoints are created by this third-party tool and you cannot delete the checkpoints with common way, I would suggest you contact NovaStor for further help.

    Best Regards,

    Candy


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    Wednesday, July 18, 2018 9:08 AM
  • Hello Candy!

    I'm also in contact with NovaStor but it looks like they are also not able to help me :(

    I hoped that maybe here can someone help me.

    Best regards,

    Michael

    Wednesday, July 18, 2018 10:50 AM
  • Hi Michael,

    I am sorry that this issue still hasn't been resolved.

    I will do more research on this issue, if I have any thoughts about this issue, I will keep you posted as soon as possible.

    It is also appreciated that the other members in our forum can share their experience with us about this scenario.

    Best Regards,

    Candy


    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com   

    Thursday, July 19, 2018 5:42 AM
  • Hello Candy!

    Thank you in advance for your help!

    Best regards,

    Michael

    Thursday, July 19, 2018 8:17 AM
  • Hi,

    The problem I mentioned in the article I recently encountered is that the backup software is provided by non-Microsoft. When manually merging a differential virtual disk (.avhdx), you cannot use the PowerShell command to delete a snapshot, indicating that the virtual disk corresponding to the checkpoint could not be found.

    However, it seems that the checkpoint cannot be deleted, maybe my method is to re-import the virtual machine.

    By the way, Is there a snapshot residue in the Hyper-V Manager when you initiate a backup task?


     


    Wednesday, August 15, 2018 8:15 AM
  • I reproduce the scene you said, that is, the corresponding disk that the snapshot point cannot find after manually merging the virtual disk. Try it, restore the virtual machine in the Hyper-V Manager.
    Wednesday, August 15, 2018 8:40 AM
  • Hello! 

    I am also having the same Problem.

    The Issue here is not the Backup software, as this is also reproducable without any backupsoftware & is an Hyper-V issue.

    The Issue comes up when you manually merge the checkpoints via the "Edit Disk" function (or powershell), the Hyper-V manager still includes those checkpoints.
    When you try to delete them there (also with the powershell command above) it tells you the corrosponding file cannot be found (yeah, I manually merged them, of course they aren't there anymore) and you cannot delete the Checkpoint in the Hyper-V Manager. 

    Now there has to be some point where the Hyper-V manager stores the information about the checkpoints other than the actual checkpoint avhdx files and this reference also need to be removed, which cannot be done "easily" when the actual avhd file is gone.

    Now I don't know if I'm missing something and I've got that problem for a while now, often exporting and importing does work, sometimes it doesn't, but there needs to be a better way than creating a new VM and giving it the merged Virtual disk.

    Ah yes, for everyone having that problem and still reading:
    SOLUTION: Create an "empty" vm without a drive, add the manually merged drive and start it up 
    -> you'll need to re-configure the network that way

    there needs to be a better way tough...

    Wednesday, June 5, 2019 12:30 PM
  • That will work, but is such a bodge!

    Microsoft, get on the ball, see that there is real life out there!

    Thursday, June 20, 2019 10:54 AM
  • Also once manual merge done, there is no easy way (I will get there in the end) to delete Snapshot folder.

    And there is no way that I know of to create VM with specific GUID (so I could delete old VM & create new VM with same GUID, so anything that uses it ie backup would be no wiser)

    Thursday, June 20, 2019 11:49 AM
  • The title of this post is a hard fact. A consistent checkpoint requires the root virtual machine config files, the root virtual machine VHDX file(s), all checkpoint config files, and all AVHDX files. When you >>>M<<<anually merge the >>A<<<VHDX (A for Automatic), you have broken the checkpoint's consistency and placed the entire virtual machine in an indeterminate state. It is not reasonable to expect the automatic tools to be able to clean that up.

    You must run the Remove-VMSnapshot command FIRST to keep the config files consistent. On the odd chance that a checkpoint leaves behind an AVHDX, THEN you can manually deal with it. If the remove does not work, then you need to stop and troubleshoot from that point. Manually merging the disk files only turns one problem into two.


    Eric Siron
    Altaro Hyper-V Blog
    I am an independent contributor, not an Altaro employee. I accept all responsibility for the content of my posts. You accept all responsibility for any actions that you take based on the content of my posts.

    Thursday, June 20, 2019 1:53 PM
  • It might be hard fact, but it is not a disaster.

    Had it happen yesterday, done merge by hand, deleted Snapshot folder, started VM and it somehow "got" lost in Hyper-V and FCM

    So simply re-imported it from same location & GUI asked about missing snapshots & what to do, chose to delete & VM is as healthy as it should be

    So it is possible (just am I not sure on exact steps)

    Friday, June 21, 2019 9:12 PM
  • Could you please elaborate on your statement "got lost in Hyper-V and FCM"?

    Could you also provide the exact steps to "re-imported it from same location & GUI asked about missing snapshots & what to do, chose to delete & VM"?

    I have two Checkpoint (Snapshot) folders but I think they are empty and they are named like a GUID id.

    Thanks

    Peter

    Wednesday, July 10, 2019 4:27 PM
  • I am sure I could not replicate it, but the VM literally got lost. It was not visible in any HV nor in FCM

    The process was running (I did check the UUID), but no access to machine.

    Killed process & simply chose to import VM in HV & pointed to its folder

    Then the questions came about snapshot (but I know there was no more snapshot as I blown it away by hand)

    Maybe one could get to the same point by just removing the VM from HV & importing it again?

    Thursday, July 11, 2019 4:11 AM