Hi,
Proxmox doesn't permit to take a snapshot when your VM has a passthru device attached, which sounds rational since snapshots by definition "freeze" (save) the whole state of the VM and that's impossible for non-emulated hardware.
BUT there are some scenarios where I think it's still useful to be able to take a snapshot and even "safe". For instance, let's say we have a VM with GPU-passthru and I'd still like to take a snapshot. Then I could power off the VM and take the snapshot when the VM is off (GPU should be powered-off and thus you shouldn't need to preserve its state; and even memory is not needed to be preserved because the VM is still off). Why isn't it permitted with Proxmox? It should be.
Now a second scenario: let's suppose we have a VM with two disks: the main one is an emulated disk while the second one is an additional disk with direct access. Snapshots are disabled due to this second disk (direct-access) but I'd still like to take a snapshot for my main disk. Proxmox could include some form of "exception" or "exclude from snapshot" configuration where you could tell Proxmox to ignore the second disk and still be able to take snapshot of the first disk (maybe this could only be permitted when VM is powered-off).
Hope Proxmox developers find these ideas useful.
Cheers,
-Román
Proxmox doesn't permit to take a snapshot when your VM has a passthru device attached, which sounds rational since snapshots by definition "freeze" (save) the whole state of the VM and that's impossible for non-emulated hardware.
BUT there are some scenarios where I think it's still useful to be able to take a snapshot and even "safe". For instance, let's say we have a VM with GPU-passthru and I'd still like to take a snapshot. Then I could power off the VM and take the snapshot when the VM is off (GPU should be powered-off and thus you shouldn't need to preserve its state; and even memory is not needed to be preserved because the VM is still off). Why isn't it permitted with Proxmox? It should be.
Now a second scenario: let's suppose we have a VM with two disks: the main one is an emulated disk while the second one is an additional disk with direct access. Snapshots are disabled due to this second disk (direct-access) but I'd still like to take a snapshot for my main disk. Proxmox could include some form of "exception" or "exclude from snapshot" configuration where you could tell Proxmox to ignore the second disk and still be able to take snapshot of the first disk (maybe this could only be permitted when VM is powered-off).
Hope Proxmox developers find these ideas useful.
Cheers,
-Román
