Please backport qemu-kvm 0.12.5 from maverick sources

[Serge Hallyn]

This would fix bug 574665.

[Unlogic (unlogic-unlogic)]

I would be really great if 0.12.5 could be backported to Lucid, cause 012.3 that currently ships with Lucid has some serious bugs.

[Serge Hallyn (serge-hallyn)]

For the moment, it will be available in ppa:ubuntu-virt/ppa. For bug 574665 I'm
going to pursue cherrypicking the relevant commit(s).

[Ash Berlin (ashb)]

Another bug fixed since 0.12.3 is http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=575628 "pxe not working with libvirt 0.7.7 + qemu-kvm 0.12" (actually fixed in 0.12.4)

[c.h. (wryfi)]

As someone who was just bit by bug 574665, I am pleading with you to please get 0.12.5 back-ported to lucid. I lost a whole 1.8TB filesystem because of this bug, and others surely will too.

[Serge Hallyn (serge-hallyn)]

Quoting c.h. (<email address hidden>):
> As someone who was just bit by bug 574665, I am pleading with you to
> please get 0.12.5 back-ported to lucid. I lost a whole 1.8TB filesystem
> because of this bug, and others surely will too.

Note that the ubuntu-virt ppa
(https://launchpad.net/~ubuntu-virt/+archive/ppa?field.series_filter=lucid)
has a backported 0.12.5 kvm for lucid.

[c.h. (wryfi)]

Thanks, Serge, I had already found and installed the PPA.

The urgency here is not for those of us who have found the bug already, but for the remaining victims who have yet to discover it. ;-)

I would generally expect data-loss bugs to be be assigned a high importance and urgent status, so that further users can be spared the pain that I and others here have felt.

[Aaron Brady (bradya)]

I'd like to second c.h.'s post - will this backport, or the cherry picked fixes, be targeted for 10.04.2? It is a data-corruption bug in an LTS, after all.

I realise that a PPA is available, but that just means another 4 years of remembering to add a PPA after installing a Lucid machine or risk losing a filesystem :)

[Serge Hallyn (serge-hallyn)]

I'm constantly tempted to do this, but maverick qemu-kvm does have bugs of its own, so by backporting we would be merely switching the problem set and regressing for users who currently are well served by the lucid version.

I am marking this invalid, and will instead keep trying to find a patchset to cherrypick.

[David Nesting (dnesting)]

I understand the rationale behind that, but this is a huge data loss bug that is continuing to bite people. Anyone using virtio with large filesystems on Lucid hosts are guaranteed to have their filesystems destroyed. If we're not going to see a backport, then it seems like we're going to continue to have a massive data loss bug in an LTS release of Ubuntu for the indefinite future? Is there some way we can at least warn users about this?

[Serge Hallyn (serge-hallyn)]

David,

you're very right, thanks for the idea. Before I continue trying to reproduce and fix, I'll see if I can push a patch which simply refuses to start qemu with a >1Tb virtio disk. I considered release notes and manpage, but honestly who'd read the manpage if they've used qemu before.