An uneducated guess, and one that assumes the 'vma_writer_close: close failed - Host is down' is not what's implied! But, could your live guest backup be failing because you do not have qemu agent installed (VMs) or enabled (PVE guest config)...
Something I forgot: ProxmoxVE9 introduced a new, still in tech-preview-feature which allows converting oci ( aka docker ) container images to lxcs. To be honest I'm not a big fan since this procedure destroys the immutability which is the biggest...
Here's my current thoughts/opinions about running docker/podman in CTs
- It currently works fine (at least in a debian CT)
- It might break on docker (related) or kernel updates
- Breakage is likely to be fixed soon but you'll have to be patient...
Sorry, but I don't see the benefit. Even if it takes a little longer to find a calculator and type in the numbers or do the math in my head, it still takes less than a minute. And if you're creating a large number of virtual machines, wouldn't it...
I haven't come across this kvm warning with PVE as yet (upgrade path PVE7->8->9). But I have encountered it after upgrading a regular Debian 12 desktop to Debian 13. The machine was unsupported and qemu would not even start. The kvm guests...