Bug#557425: lenny->squeeze upgrade -> system no longer bootable

[Jonathan Nieder]

clone 557425 -1 -2
retitle 557425 lenny->squeeze upgrade, debconf defaults -> system unbootable
retitle -1 please produce a grub.cfg that can be used by payload from lenny
severity -1 wishlist
submitter -1 !
retitle -2 upgrades should run grub-install as a safe default
severity -2 serious
thanks

Josip Rodin wrote:
> On Sun, Nov 22, 2009 at 01:49:51AM +0100, Josip Rodin wrote:

>> I'll go reboot and try to insert 'insmod linux' in those Linux menu entries
>> that no longer work.
> 
> Yep, that worked, together with the removal of the 'search' line which
> complained about the no-floppy parameter. I logged in, ran
> dpkg-reconfigure grub-pc, explicitly selected /dev/sda to install onto,
> and after that rebooted, and all is well again.

Okay, so I see two bugs here:

 - 'update-grub' in squeeze is producing a grub.cfg cannot be used with
   grub2 from lenny.  It would be really nice to fix this, so one could
   upgrade the package and the actual bootloader as separate steps.

   This would also make it easier to recover from situations where the
   grub-install subtly fails.  e.g. I have stupidly made grub-install
   write to the wrong partition before.

 - The debconf prompts have completely wrong defaults.  I think it would
   be nice to detect what version of the bootloader is already installed
   and give appropriate advice, but short of that, grub should default to
   installing the bootloader.  Anything else would be unsafe.

Fixing either of these would fix your symptom, so I’m leaving this bug
as is to track the issue.

> So, please detect the situation where leaving the system in its current
> state would render GRUB useless, and adjust the default accordingly.
> 
> The default setting should be to NOT screw the user. :)

Agreed.

Thanks,
Jonathan