Hyper-V Virtual Machines disappear after rebooting

Question

Hi. I have two servers, one is a Windows Server 2019 with the Hyper-V role and another is a Windows 2016 Server with the Hyper-V role installed. All of my virtual machines are configuration version 8.0. I setup Hyper-V replication to replicate the Virtual Machines on the 2019 host to the 2016 host. This works fine and replicates the VM's I have selected. When I reboot the Windows 2016 server I notice that in the Hyper-V Manager console all the Virtual Machines that had been replicated are gone and do not show up. I found other articles to check the folder C:\ProgramData\Microsoft\Windows\Hyper-V\Virtual Machines for symbolic links however this folder is completely empty. I checked the drive location where I setup the replication and the virtual machines and virtual hard disks are there, so I know the data still exists but why are all the VM's gone? I don't find anything in the event log to indicate an issue, and I have reformatted the 2016 Hyper-V host with a clean install and run into the same issue. Any ideas on why and how to fix this?

Answer 1

Hi. Any updates on this issue?

Answer 2

Hi, I've been suffering a similar problem.
About one month ago a number of replica VMs disappeared from a replication server.
The first I noticed was that the replication state went to critical on the live Hyper-V server, for several machines.
I spent some time rebooting and Googling for solutions, all to no avail. All machines involved all have the latest updates, and are 2016 or 2019 versions of Server.
My solution took two forms:

1. Remove replication from live Hyper-V server for the lost replicas. Stop the Hyper-V service on the replication server. Identify the GUIDs for the lost machines. Search the file structure of replication server and remove all files and folders related to the GUIDs of the lost machines. Then start the service and attempt to reenable replication.
   For some lost replicas, this worked.
2. For the remaining ones, I imported old Exports of the lost machines to the Replication Server. Then Deleted them again. Then I was able to reenable replication.
   It feels like the process of importing a machine and then deleting it, seems to clean up properly, and allow replication to be re-enabled.
   It implies that I am missing something when attempting to cleanup these lost machines.

Its now 4 weeks later in June, and its happened again. Two more replicated machines have gone missing. These machines were not involved in the previous episode.
I'm currently going through the process of importing an export, so I can delete it, and re-enabled replication.

Best regards,
John Semmens

Answer 3

Hi Lyle,
Thanks for your insights.
It turns out this time, I had to do something similar.
I could not figure out how to remove the remaining traces of the lost replicated machines, in order to allow them to be replicated again. (I must have been lucky last time). This is despite deleting all files and folders related to the machine's GUIDs. Including those within the folder: C:\ProgramData\Microsoft\Windows\Hyper-V\, which appears to be where the list of machines is maintained.
This time around I had to force the creation of new GUIDs on the live machines by exporting and re-importing with "copy" to create new GUIDs. Then replication could proceed as normal.

Best regards,
John Semmens

Answer 4

hi Guys,

thanks for sharing your experiences..

Unfortunately we ran in to this exact issue as well. Source server is 2019 and target replication server is 2016. After reboot VM's seem to disappear.
We reinstalled the Server 2016 just uit of pure despair. But unfortunately we still have missing VM's and are able to reproduce it very easy...

VM configuration is version 8.0 and the VM's are healthy on the source 2019 server. Initial replication goes prefect.. but after a reboot (Or after restarting the Hyper-V Management services) the replications are gone.

If anyone of MS is interested in troubleshooting/learning about the problem I'm willing to collaborate to solve the issue.
For now, my only option is reinstall the 2016 server in 2019 and pray this will work...

any other good advice will be very welcome;)

Jacob

Answer 5

I 100% agree with you. And I don't see MS even addressing the issue to fix it even though I straight out proved it to them that it was not corrupted and was some kind of issue going between 2016 to 2019 and back to 2016. :-)

Lyle Epstein
Kortek Solutions
A Microsoft Silver Partner