[lug] Grub question

[Collins Richey]

On 11/10/06, Kenneth D. Weinert <kenw at quarter-flash.com> wrote:
> Lee Woodworth wrote:
> > Ken Weinert wrote:
> >> Lee Woodworth wrote:
> >>> Ken Weinert wrote:
> >>>
> >>>> Well, I'm not sure how I did it, or what exactly I did, but grub is sort
> >>>> of non-working right now.
> >>>>
> >>> When this has happened to me, reinstalling grub on the boot drive
> >>> has fixed things.
> >>>
> >>> (I have a /boot partition on hda1, system is on hda2, grub boot sector
> >>> on hda)
> >>>
> >>> # grub
> >>> root (hd0,0)
> >>> setup (hd0)
> >>> quit
> >>>
> >> I'll give that a try when I get home tonight and let you know if that
> >> fixes it. If not I'll post up the info the other responder asked about
> >> for further discussion.
> >>
> >> Any ideas on can cause this temporary insanity?
> >>
> >> And no, I've not added/deleted drives or partitions, just compiled up a
> >> new kernel and tried to add it to the boot menu. Yes, that implies that
> >> I messed up the boot menu somehow, but I've not yet seen it and I didn't
> >> keep a copy of what it looked like before (why should I? what could go
> >> wrong? :)
> > This has happened to me when I changed /boot/grub/grub.conf to add a new
> > kernel line. I suspect that grub.conf moved to a different set of blocks
> > when the file was rewritten.  It appears the early boot stage has the
> > config file location hard-coded as  block addresses so it didn't know
> > where the config was anymore. The grub setup command looks for the grub
> > boot code and could be calculating block addresses that it inserts into
> > the early stage boot loader.
>
> Yes, I had added a new kernel line before this madness started. The good
> news is that re-running grub as said before restored it to a working
> condition.
>
> Thanks to all for the assistance - it's much appreciated.
>

I have also seen this behavior after grub software updates. I have a
multi-boot system, and occasionally I have to boot another distro to
fix a problem. My CentOS4 distro, for example, does not always produce
a bootable grub when running grub setup. Not too surprising, since
CentOS4/RHEL4 is pretty aged at this point.

-- 
Collins Richey
     If you fill your heart with regrets of yesterday and the worries
     of tomorrow, you have no today to be thankful for.