DPM 2012 R2 is leaving avhd files on Hyper-V host after backup RRS feed

  • Question

  • Hi

    I am running DPM 2012R2 (version 4.2.1603.0) on a Windows 2012R2 server and it is backing up two VMs on a Hyper-V 2012R2 host which has Hyper-V replication enabled and set to replicate every 300 seconds for one of the VMs.

    I have noticed that the drive containing the VM has filled up with .avhd files which are generated each time a DPM backup is run.  I can see checkpoints in the Hyper-V manager, but other users (administrators) cannot.  I am also unable to access the settings for them and get an unhandled exception error and also another error message stating: "Hyper-V encountered an error trying to access an object on computer '<serverName>' because an object was not found.  The object might have been deleted.  Verify that the Virtual Machine Management service on the computer is running."

    It seems that the checkpoints I can see are corrupted or non-existent as far as Hyper-V manager is concerned, and I am reluctant to start trying to merge them manually at this stage as the server is a production machine and in constant use and also has .avhd files set as the hard drive in Hyper-V settings.

    Does anyone know, firstly, what could be preventing these files from being cleared up by DPM/Hyper-V after a backup and how I could therefore prevent this from happening again in future, and secondly, how to remove/merge the existing files toresolve my current problem?

    Any advice would be greatly appreciated,



    • Edited by chris624 Tuesday, August 28, 2018 11:39 AM
    Tuesday, August 28, 2018 10:57 AM


All replies

  • Hello,

    Have you made sure that these checkpoints are made by DPM and not any leftovers from manual checkpoints?

    I would suggest you to manually merge the checkpoints and once there are no checkpoints left, keep monitoring the next time your backup runs and check for left over avhd/avhdx.

    If they reappear after the next backup, then check closely at what times they appear to see if there's any pattern. 

    Hyper-V Replica is supported with DPM backups, but I suspect something is colliding.

    If possible, after cleaning the checkpoints try pausing the Hyper-V replication to see if there's any change.

    Also are you getting any errors/warnings in DPM?

    Best regards,

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    Tuesday, August 28, 2018 11:54 AM
  • Hi Leon,

    They are definitely from when the backups run judging by the time stamps and also that there are so many.  There are 12 associated with the C drive and 83 with the F drive which is that much larger.  It may take some time to manually merge them but I will look into doing this.

    Having looked at the link you provided regarding DPM support, I take it that I can backup the replica instead of the primary with these versions of DPM and Hyper-V host?  If so I will try this and stop backing up the primary VM.

    Thanks for your help,



    Tuesday, August 28, 2018 1:55 PM
  • Yes try changing by backing up the replica instead of the primary VM, let us know how it goes!

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    Tuesday, August 28, 2018 2:01 PM
  • I may need to wait until Thursday as I am unable to shutdown the VM until then as it is a production server (am I correct in thinking the VM needs to be powered off first before merging AVHD files?)
    Tuesday, August 28, 2018 2:33 PM
  • Yes that's right, the VMs need to be powered off to be able to merge the avhd/avhdx files.

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    • Proposed as answer by Leon Laude Thursday, July 4, 2019 3:22 PM
    • Marked as answer by chris624 Wednesday, September 25, 2019 10:28 AM
    Tuesday, August 28, 2018 2:39 PM