[CentOS] Grub fallback problem

Mon Aug 3 17:54:29 UTC 2009
Filipe Brandenburger <filbranden at gmail.com>

Hi,

On Mon, Aug 3, 2009 at 13:44, Matthias
Blankenhaus<matthiasblankenhaus at yahoo.com> wrote:
> I am running CentOS 5 (core pkgs) / x86_64 using grub 0.97 and I am trying to configure a fallback between two partitions on my local disk, each installed with a CentOS image.   The idea is to be able to install a new test OS image and fall back in case of a problem to the default image.  This is a great grub feature !  Except it does not work for me :(

I believe RedHat patches this feature out of Grub, at least that was
what one of the bugs in RedHat's bugzilla was complaining about (BTW,
that bug was posted in this list a couple of days ago, probably in the
same thread you started). However, I did not confirm that statement,
it might be wrong. Inspecting the grub SRPM and the patches it applies
might confirm that.

The bug said something about RedHat adding a custom patch to achieve
the same effect, the patch would store the "default" and/or "fallback"
boot option inside the stage2 file. Though, I did not find any
references to that mechanism or any documentation of it. You might
have to look into the source and patches to see how that is done...

All I can say at this point is "Read the Source, Luke!"

HTH,
Filipe