[CentOS-virt] win2008r2 update on centos 6 host made system unbootable

Wed Dec 9 13:23:57 UTC 2015
Dennis Jacobfeuerborn <dennisml at conversis.de>

On 09.12.2015 13:47, Patrick Bervoets wrote:
> Op 09-12-15 om 01:00 schreef Dennis Jacobfeuerborn:
>> On 09.12.2015 00:39, NightLightHosts Admin wrote:
>>> On Tue, Dec 8, 2015 at 5:26 PM, Dennis Jacobfeuerborn
>>> <dennisml at conversis.de> wrote:
>>>> Hi,
>>>> today we ran into a strange problem: When performing a regular Windows
>>>> 2008r2 update apparently among other things the following was
>>>> installed:
>>>> "SUSE - Storage Controller - SUSE Block Driver for Windows"
>>>> [...]
>>>> [...]
>>>> What worries me is that I want to update other win2008r2 guests as well
>>>> but now fear that they will all be rendered unbootable by such an
>>>> update.
>>>> Regards,
>>>>    Dennis
>>>> _______________________________________________
>>>> CentOS-virt mailing list
>>>> CentOS-virt at centos.org
>>>> https://lists.centos.org/mailman/listinfo/centos-virt
> Which virtualization are you using? KVM?
> How did you get that update offered?
> I can't reproduce it, but then my servers are on a patch management
> software.
> And I can't check on WU because I don't want to install the new update
> client.
> Anyway, I would uncheck that patch when updating the other guests if I
> were you. And work on a copy / snapshot.

Yes, this is a CentOS 6 Host using regular libvirt based virtualization.
The Suse driver is apparently an optional update that gets delivered
using the regular Microsoft update mechanism.
It's hard to believe that they didn't catch a completely broken driver
during QA so my hypothesis is that maybe the new Virtio driver is
incompatible only with the older Kernel of CentOS 6 and that this wasn't
properly tested. To verify this one could check if the same thing
happens on a CentOS 7 Host but at the moment I'm to busy the check this.