I had a problem with a client’s file server yesterday. They had installed RH9 on it and did software RAID level 1. They only had one ext3 partition on the two disks- just the root filesystem and no separate /boot. Because of the ineptitude of Red Hat’s grub-install script, the machine could not boot after grub was reinstalled.

I had to deal with a similar problem before, but I couldn’t remember the exact grub commands. In the end, I figured out the solution.

    # grub
    grub> device (hd0) /dev/hde
    grub> root (hd0,1)
    grub> install (hd0,1)/boot/grub/stage1 (hd0) \
       (hd0,1)/boot/grub/stage2 \
       (hd0,1)/boot/grub/grub.conf
    grub> device (hd1) /dev/hdg
    grub> root (hd1,1)
    grub> install (hd1,1)/boot/grub/stage1 (hd1) \
       (hd1,1)/boot/grub/stage2 \
       (hd1,1)/boot/grub/grub.conf
    grub> quit