Re: Grub2 with multiple Debians
On Fri, 14 Sep 2012 20:42:21 +0000 (UTC)
Hendrik Boom <hendrik@topoi.pooq.com> wrote:
> On Fri, 14 Sep 2012 23:25:03 +0300, Andrei POPESCU wrote:
>
> > On Vi, 14 sep 12, 17:12:38, Hendrik Boom wrote:
> >>
> >> Of course, after I've made my copy (with slight changes
> >> to /etc/fstab) I have two nearly identical sets of partitions, so
> >> it may be tricky to tell them apart. Is grub2 clever enough to
> >> figure it all out anyway? And what data does it use to this end?
> >> (so I can make sure it's right!)
> >
> > UUIDs? What failure mode(s) do you have in mind, because I can't
> > think of any.
>
> It probably is os-prober that I mean. The misconfiguration I have in
> mind is matching one system's /boot with another systems's /. I've
> had it happen on a laptop sometime ago. and it sure messed up my
> upgrades. I have no idea how it happened, but it has made me
> paranoid.
>
The problem is that update-grub rewrites /boot/grub/grub.cfg. It may be
possible to specify roots and boots in /etc/grub.d/ (I do use a
separate /boot, but I've never needed to try this) or alternatively it
is perfectly possible to edit grub.cfg, but you need to remember to do
so each time update-grub is run, before rebooting. More than once, I've
known versions of grub not deal correctly with a separate /boot, so
I've had to do this until the bug was fixed.
Both update-grub and grub-mkconfig (which it calls) are scripts and
possibly some kind of user warning could be appended to one of them.
Or perhaps if the backup copy were made to a second hard drive (trickier
with a laptop) then os-prober could be trusted not to mix roots and
boots between drives.
--
Joe
Reply to: