Manually merge checkpoints if chain is broken

I had a situation when VM had 42 checkpoints after backup failure. I’ve tried the actions from my article Merge checkpoints (avhdx / vhdx), but it didn’t work, I had┬ácatastrofic failure error.┬áThat means the chain of snapshots (checkpoints) is broken.

Follow these steps to fix the issue:

  1. Turn off the VM and backup VM’s content
  2. Open Hyper-V Manager where is VM located. This will assures you have proper access permissions to the virtual disk
  3. Click on Edit disk, select the folder where VM keeps it’s vhdx
  4. Select very last check point file (with .avhdx extension)
  5. Select “Merge”
  6. You will be asked to confirm merge this file with the parent disk. The parent disk is a previous .avhdx file
  7. Do it until you have no avhdx files in VM’s folder. At the end you should have just single vhdx file
  8. Your VM will not run with this disk, because its only remember last avhdx file. Create new VM and copy vhdx file to there, attach it in VM’s hardware configuration.
  9. You will need to reconfigure network settings as well because your VM also get new vNIC.

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  1. I copied vhdx and avhdx files to test environment after powering off the virtual machine. after selecting latest avhdx file in hard drive setting(vm settings) i power on the VM in test environment. i am getting the error “The chain of virtual hard disk is inaccessible. There was an error opening a virtual hard disk further up the chain. When try to merge using edit disk wizard after selecting latest avhdx it is asking for reconnect to parent. then i selected parent. when i try to finish the wizard it is saying failed to set new parent. id mismatch … do you provide solution for this problem? live environment running on the file(which was a avhdx renamed to vhdx) do you provide solution for this problem?

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