On 16.03.22 20:32, DERUMIER, Alexandre wrote: > From my tests: > a already booted vm without the balloon freepage option enabled ---> > migrating to new vm with balloon freepage option enabled : works > > Then failback it to previous node : works > > > But starting a new vm with the option enabled then migrate it to a new > vm withtout the option: > > migration die on resume. > > 2022-03-16 20:28:30 average migration speed: 1.5 GiB/s - downtime 30 ms > 2022-03-16 20:28:30 migration status: completed > 2022-03-16 20:28:30 ERROR: tunnel replied 'ERR: resume failed - VM 104 > not running' to command 'resume 104' > 2022-03-16 20:28:39 ERROR: migration finished with problems (duration > 00:00:18) > TASK ERROR: migration problems >
I now tested with a Debian Testing (bookworm) VM and ensured it actually logs "Free page reporting enabled" in the kernel log and you're right it fails there. But that's only relevant for migrating a VM that got freshly started (!) on a new (upgraded) host and then gets migrated to an old one, and that's something we never supported anyway (besides some very light best-effort). As the VM doesn't even crashes then, and just fails to migrate (source VM stays running), it's not even problematic for that case; the admin can just upgrade the qemu-server on the other node already and continue. Same holds for live-snapshots, only a snasphot from a freshly started VM on an already upgraded host would cause issues on rollback, but *only* on an old host, so the same as any QEMU update would cause anyway. So, it seems we can just enable it with 6.2 as machine guard and be done. > > If think this is because guest kernel balloon driver enabled it at boot > only. > yeah seems so. > > Note that I don't think that current windows drivers already support it > (I have looked at the source code, so even if the option is enabled at > qemu level, it don't do nothing inside windows. > So I think that migration will works in both direction with windows > vms. _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
