Comment 30 for bug 978464

On Mon, May 07, 2012 at 09:14:53PM -0000, Phillip Susi wrote:
> On 5/7/2012 3:28 PM, Steve Langasek wrote:
> > This has never been the case because we don't believe we have a reliable
> > enough way to identify the correct device to write to.

> It has been the case for some time now. We use debconf to store the
> devices that need grub reinstalled on upgrade. You can run
> dpkg-reconfigure grub-pc to update/correct the list.

Right - Colin set me straight on this. Sorry for the confusion.

> > Regardless, this is not behavior that it's reasonable to change in an SRU.
> > We need to fix the grub.cfg to be compatible with lucid grub.

> If you upgrade to precise, you should no longer be running the precise
> grub, not lucid grub. The grub ABI is not stable, so whenever a new
> grub package is installed, the MBR/core image must also be updated or
> breakage will happen when it tries to use the updated modules in
> /boot/grub. The same rationale applies to the config file.

Yes. But AIUI there are always some cases where we cannot upgrade grub on
the MBR for one reason or another, and this seems to be one of them - so we
really ought to preserve format compatibility where possible.

Dave, can you speak to why grub wouldn't have been upgraded in your case?
What's the output of 'debconf-show grub-pc' for you on the affected machine?