Problem with VM; Server 2016

Question

Hi,

I've got Windows Server 2016 Server running Hyper-V. I have one of the Hyper-V machines I've managed to mess up.

I have desactivated checkpoints, because they always cause problems, but I still have a .avhdx file. It's dated from two days ago while the main disk is dated today. These are the only two files.

(I tried exporting 2 days ago and had some issues, mainly lack of disk space)

I just want to get this running again, had stopped it to do the export.

Not the first time I've messed this up, not sure why this happens, I must be doing something wrong! I have restarted the host machine a few times but that hasn't helped.

If i try to start the stopped VM it says the disk chain is damaged.

When I open up hard disk settings it shows the .avhdx file. If I click inspect I get an error about MaxInternalSize not existing.

If I try to go back to the main disk (I can loose two days data thats better than loosing everything) it says a disk merge is pending.

How to do get out of this mess and get my VM running again? I do have a veeam backup but I'm afraid to touch anything at this point.

I don't mind recreating the VM in hyper-v but I'd like to get at least most of my data back (it's a linux vm with data on it).

Thank you,

Answer 1

Found a solution:

https://blog.virtualcenter.com/2019/01/19/property-maxinternalsize-does-not-exist-in-class-msvm_virtualharddisksettingdata-vhdx-on-hyper-v/

Be sure to put the full path of the disks in, I forgot that at first, worked great once I did that!

Answer 2

Hi KC76,

Thanks for your post. This can happen because of hardware problem like storage LUN going full and pause, third party backup software trying to back up a full VM while failing over and over causing detached out of sync snapshots and broken disk chains.

Is there anything in event viewer?

I would suggest you to use proc mon to identify if there is nothing on the event viewer.

If your virtual machine had snapshots, these snapshots can sometimes cause disk chain corruption. Try to merge or delete any snapshots that might exist.

Open the Hyper-V Manager and right-click on the virtual machine. Go to "Settings" and examine the disk configuration. Ensure that all disks are correctly attached and the paths are accurate.

Best Regards,

Ian Xue

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