asked on

Server 2016 Standard Hyper-V Guest will not start.

Server 2016 Standard Hyper-V Host volume ran out of diskspace. Guest Hyper-V was unable to start.
Guest Hyper-V had 1 Snapshot which I deleted via Hyper-V Manager. Snapshot appeared to delete. However, I did not see Merge take place and .avhd file remained intact.
From Hyper-V Manager SCSI Controller, selected Virtual hard disk and Inspect. Received notification Virtual Hard Disk Chain was broken. Please reconnect the child to the correct parent virtual hard disk. I followed Reconnect process and selected Ignore ID Mismatch. It appeared to complete successfully and started the Merge process. The Merge process stoped/disappeard at around 40% with no error. The .avhd file was removed and ~ 5GB disk space was available. However, when I try to start VM, I receive attached error:

I did make backup copy of .avhd and .vhd files prior to makinng changes. To recover data, I tried to rename .avhd file to .vhd file and Mount via File Explorer. I receive: Couldn't Mount File. There was a problem mounting file.

Any suggestions would be greatly appreciated. Please let me know if you need additional informamtion.

ASKER CERTIFIED SOLUTION

Philip Elder

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

atsanders

ASKER

Hi Philip,
Apologizes for delay. Thanks for quick response and info. I seem to be in a catch 22. When I try Manual Merge, Merge is not an option under Edit Disk. Options are Compact, Convert, Expand. I must go into Virtual hard disk and Inspect. Once again I receive notification Virtual Hard Disk Chain was broken. Please reconnect the child to the correct parent virtual hard disk. I followed Reconnect process again and selected Ignore ID Mismatch. It appeared to complete successfully and started the Merge process. The Merge process stoped/disappeard at around 40% with no error.

This time I tried mounting the resulting .vdx file from File Explorer. It does mount. Unfortunately, very little updated data. I'm wondering if .avdx file is corrupt. Any other thoughts?

Have a great US Thanksgiving! ;)

Philip Elder

After renaming the .AVHDX to .VHDX it does not allow the process indicated in the TN article?

Happy Thanksgiving to you. :)

atsanders

ASKER

Good morning Philip,
Correct.. In TN article, Step 5. Merge is not an option. Only Compact, Convert, Expand.

Philip Elder

That's not a happy place to be in.

Is there a known good backup that can be restored?

atsanders

ASKER

HA! I was afraid of that. "Fortunately", client has current backup of Data. System State and VM's not backed up. I'm in process of rebuilding VM. I'm almost positive I created snapshot back in 2019 and forgot to delete. That won't happen again. Philip... Thanks so much for taking the time and assistance. Much appreciated sir!

Philip Elder

Does the host have Volume Shadow Copy snapshots enabled?

If yes, you may be able to pull a copy of the needed .AVHDX or even the .VHDX parent file to get the VM to boot and at least work through cleaning up ADDS, resyncing user and machine passwords (I've lost domain trust), and get them going with a lot less pain.

If you do need to greenfield, that is do a side-by-side new ADDS, please use a slightly different domain name and NETBIOS name to avoid Group Policy Tattoo issues. BTDT

atsanders

ASKER

Good thought. Unfortunately, VSC Disabled. Fortunately, VM was not the DC. It was the License, File, and RDS server. Hopefully they have RDS CAL's and Activation keys documented.

Philip Elder

RDS CALs should be either paper or in the Microsoft VLSC portal.