AVHDX files left on Hyper-V Server after backup-error

[Retrofreak]

Hi,
I just wanted to try if veeam agent is okay, to do a manual backup on our hyper-v server. It started, created suddenly avhdx files of all (7) VM's, then after a while suddenly the access to the destination (synology-nas DS918+) failed (I dont know why, it just stopped working). Backup broke with errors (destination missing...). The problems now are the leftover-"*.avhdx" Files. They are NOT shown as snapshots in the hyper-v manager?! In powershell (Get-VMSnapshot) also no information. But they are active and in use!! How can I merge the snapshots back to the original VHDX? Please help, they are growing fast!! Why does Veeam-Agent produce those AVHDX at all, without asking for it? Isnt VSS-Shadow-Copy enough? Can I disable creating avhdx the next time? Sorry, I'm in a kind of panic. Please help me to get rid of those mystic AVHDX Files... Please.....

[DGrinev]

Hi Mirko and welcome to the community!

In the situation you've described it's worth to contact the support team, since the log diving is a huge part of investigation to understand the real cause of the issue and apply the right fix.
Please do not forget to share the case id here, so we can track it internally. Thanks!

[Retrofreak]

Hi, thanks for the reply!
Meanwhile I got rid of those avhdx containers: First I ran veeam agent again to a local destination (USB harddisk). Then there were still some avhdx left, but a few less than before. I cloned the affected vm's, and did some other manual repair-trying and so I got "new" clean, one-file vhdx-machines. But the process needed a lot of my nerves and time. I think it would be a good option in veeam agent to choose disabling the creation of Hyper-V avhdx containers.

Some links, that helped me
> https://blog.workinghardinit.work/2015/ ... l-machine/
> https://blog.workinghardinit.work/2014/ ... eckpoints/
> https://www.altaro.com/hyper-v/how-to-m ... eckpoints/
> https://gallery.technet.microsoft.com/s ... e-72a96c17

[Gostev]

Wait, do you have Veeam Agents installed on the Hyper-V host itself (which is totally unsupported for VM backups), or inside of the each VM (which is fine)?

[Retrofreak]

Hi,
Yes, I know now. But I did not get it before the problem happened...
So I just looked for a quick solution to backup the full host system manually once, and in my childish carelessness I thought veeam agent would be great for this job... So I tried, and got into trouble. Now I know, after bleeding.
I think the manual one-time backup probably will work, if I shutdown the Hyper-V guests before starting the backup?! But I am not in the mood to try. Perhaps sometime in the near future. I will report.