Bug#544157: Bug#544155: [grub-pc] grub update renders system unbootable (unaligned pointer 0x700ba)

[Felix Zielcke]

Am Samstag, den 29.08.2009, 14:23 +0200 schrieb Martin Steigerwald:
> > > > > Then I booted into grml, overwrote the swap partition and
> > > > > recreated it via mkswap in order to make sure the TuxOnIce
> > > > > snapshot is invalidated to avoid data loss in next boot.
> > > > >
> > > > > Then I chrooted to my debian system after bind mounting /dev,
> > > > > /proc, /sys to it, downgraded grub-pc to 1.96+20090317-1 from
> > > > > squeeze and ran grub- install.
> > > > >
> > > > > I thought about running grub-install for the grub-pc from
> > > > > unstable, but I read the current sid version might be broken
> > > > > anyway[1], thus I thought I'd better downgrade to the squeeze one
> > > > > in order to get a working system quickly again. I could try
> > > > > updating to the sid one again, without running grub-install
> > > > > manually and then I run it manually and see whether it fixes the
> > > > > issue. So you could know whether its grub itself or a missing
> > > > > grub- install.
> > > >
> > > > If grub-install doestn't get run then /boot/grub still has the old
> > > > grub and so nothing actually changed, except if grub-mkconfig
> > > > generates a different grub.cfg.
> > >
> > > So since something changed it means that grub-install has been run?
> >
> > It should be run, else it can happen that you can't boot your system.
> > For example we added `--no-floppy' to the search lines, but an older
> > GRUB 2 doestn't understand it and so prints an error.
> 
> What about the following test:
> 
> - upgrade grub-pc from squeeze to sid again
> - reboot
> - if it gives the same error, run grub-installl
> - reboot
> 
> ?

You can't test if the system booted fine with the config or not.

> I wonder whether I should run dpkg-reconfigure grub-pc and enable grub-
> install on upgrades before. I think otherwise it doesn't make much sense. 
> Actually I think grub-pc post install should make it a bit more difficult to 
> render the system unbootable and thus should always ask whether it should 
> run grub-install and default the question to yes. Probably it should only 
> be asked on lower debconf priority and just be done in any other case.

We need to ask for the device. We can't assume /dev/sda or /dev/hda is
always the one where you have GRUB in MBR installed.


> 
> > > > > This is on an IBM ThinkPad T42.
> > > > >
> > > > > [1] http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=540125#75
> > > >
> > > > I should have mentioned that I meant the 1.96+20090825-1 and 1.96
> > > > +20090826-1 at that time currently in sid and not the
> > > > 1.96+20090826-3.
> > >
> > > So I should try the unstable one again?
> > >
> > > What would be your directions?
> >
> > You can also try the current squeeze version which is 1.96+20090808-1
> > That uses the new Linux loader too.
> > With linux16 and initrd16 you can try out the old one. That should
> > work.
> 
> Well I do use the current squeeze version right now:
> 
> shambhala:~> apt-show-versions | grep grub-pc
> grub-pc/squeeze uptodate 1.96+20090317-1
> 
> And this one works. The one that didn't was the sid version. And thus I 
> downgraded to the squeeze one. So squeeze versions works while sid one did 
> not work.

The mirror you use is broken or outdated.
http://packages.debian.org/search?keywords=grub-pc
http://packages.qa.debian.org/g/grub2.html
Both say 1.96+20090808-1 is in testing/squeeze.
Anyway the 0808 version or the 0823 currently in sid shouldn't matter.


-- 
Felix Zielcke
Proud Debian Maintainer