Cannot snapshot VM - VFIO migration not supported

[TheBokke]

Hi folks,

I'm trying to snapshot a VM running TrueNAS Scale. Never had any issues before, but when trying to create the snapshot I get this error:

TASK ERROR: VM 100 qmp command 'savevm-start' failed - 0000:01:00.0: VFIO migration is not supported in kernel

I read something about the NoVNC clipboard in this thread:

https://forum.proxmox.com/threads/qmp-command-savevm-start-failed-the-vdagent-chardev-doesnt-yet-support-migration.174785/imilar issue.

But I don't see a solution or workaround.

Any suggestions appreciated.

 

[fiona]

Hi,
migration with noVNC clipboard will be supported in an upcoming qemu-server release, under the condition that the machine version of the VM is at least 10.1. It's already applied in git, but it's not packaged yet.

 

[TheBokke]

Hi,
migration with noVNC clipboard will be supported in an upcoming qemu-server release, under the condition that the machine version of the VM is at least 10.1. It's already applied in git, but it's not packaged yet.

Thanks Fiona. Is there another way to create a snapshot not using noVNC clipboard? I don't seem to have this issue on my other VM's and can create a snapshot from the Proxmox UI no problem.

 

[fiona]

Unfortunately no. You'll have to wait for the new qemu-server package (or apply the patch yourself if you have experience with such things), then snapshots and migration will work for VMs running machine version >=10.1.

 

[firsway]

Hi,
migration with noVNC clipboard will be supported in an upcoming qemu-server release, under the condition that the machine version of the VM is at least 10.1. It's already applied in git, but it's not packaged yet.

Hi, I have the same error trying to snapshot an Ubuntu VM but this time on Proxmox 8.4.16. Exact error below.

snapshot create failed: starting cleanup
TASK ERROR: VM 101 qmp command 'savevm-start' failed - 0000:0c:00.3: VFIO migration is not supported in kernel

The interesting thing about this is that snapshots for other VMs on the same box work without issue.
The only difference with the VM that fails is that it passes through to a GPU.
Is there any more information I can provide to help? Thanks in advance.

 

[fiona]

Hi @firsway,
you cannot snapshot the VM if it has a passed-through GPU, since the GPU state cannot be preserved. The error is expected. There is an experimental flag, you could try at your own risk:

live-migration-capable (PCI): This marks the PCI device as being capable of being live migrated between nodes. This requires driver and hardware support. Only NVIDIA GPUs with recent kernel are known to support this. Note that live migrating passed through devices is an experimental feature and may not work or cause issues.

 

[Rick_W]

I see almost an identical error taking a snapshot of a Linux VM with pass through audio. I find the snapshot works if I shutdown the VM and restart after. I know that's inconvenient depending on what your VM is doing but it works.

 

[firsway]

Hi @firsway,
you cannot snapshot the VM if it has a passed-through GPU, since the GPU state cannot be preserved. The error is expected. There is an experimental flag, you could try at your own risk:

Hi @fiona ,

Thanks for your response. I might try out the experimental approach and just make sure I have a good backup beforehand!

 

[firsway]

I see almost an identical error taking a snapshot of a Linux VM with pass through audio. I find the snapshot works if I shutdown the VM and restart after. I know that's inconvenient depending on what your VM is doing but it works.

Thanks, will give that a try also..

 

[fiona]

Hi,

I see almost an identical error taking a snapshot of a Linux VM with pass through audio. I find the snapshot works if I shutdown the VM and restart after. I know that's inconvenient depending on what your VM is doing but it works.

if you shut down, only the disks need to be snapshotted. There is no device state when the VM isn't running.