Peter Olson <peabo@???> wrote:

> I have a machine in that state right now, and rather than try to debug it at the Grub prompt, I am just going to reinstall the system.

That's a bit like the old "I'm buying a new car because the ashtray is full" joke.

If you've managed to screw up your kernel and/or init image then that's not a grub problem - a bit like blaming Goodyear (or whoever) because you drove over a rock and shredded both the tyre and rim.
If you haven't then the system is recoverable.

Many installers have a rescue option (may be under an advanced submenu) that will allow you to boot the system and mount your chosen partition as a temporary root. Then "update-grub" "grub-install /dev/..." should fix it.

Or you can do it manually. Boot off a live disk and
mount /dev/... /mnt
mount /dev/... /mnt/boot (if you use a boot filesystem)
mount -o bind /proc /mnt/proc
mount -o bind /sys /mnt/sys
mount -o bind /dev /mnt/dev
chroot /mnt
- fix your grub setup
exit the chroot,, unmount filesystems, sync, reboot

That usually does it for me.

Or simpler than the above, give http://www.supergrubdisk.org a try. It was suggested to me last week, and it's really good.