kvm + raid1 showstopper bug

Pete Ashdown
2012-02-17T04:57:34Z

I've been waiting for some response from the Ubuntu team regarding a bug on
launchpad, but it appears that it isn't being taken seriously:

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/745785

We are running Ubuntu Natty 11.04 with KVM with our storage on RAID10 + drbd.
While we were running the resync command, we could expect an IO block during
every resync. I eventually disabled resync. Yesterday we had a kernel panic,
which I am presuming may trace back to KVM and its interactions with RAID10.
I run KVM on some other boxes with some built-in Dell hardware RAIDs. They
have been stable for well over a year on Ubuntu 10.04.

Here are the 11.04 current versions if that helps.

kvm 84+dfsg-0ubuntu16+0.14.0+noroms+0ubuntu4.4
kvm-pxe 5.4.4-7ubuntu2
qemu-kvm 0.14.0+noroms-0ubuntu4.4
drbd8-utils 8.3.9-1ubuntu1

What I'd like to know is if this bug between KVM & RAID1 is known and whether
it has been addressed in newer versions of the kernel and/or KVM. I'm on the
verge of buying a hardware RAID card to resolve this and I'd rather not have
to deal with that. Software RAID is so much nicer to manage.