How to Repair or Reinstall GRUB Bootloader on SUSE Linux

If your GRUB bootloader is damaged or missing on your SUSE Linux system, you can repair or reinstall it using the rescue system on your installation media. This guide will walk you through the process step-by-step.

Requirements

Before you begin, make sure you have the following:

SLES/SLED 10 installation media (CD or DVD)
Root access to your system
Knowledge of your root partition device name (e.g. /dev/sda2)

Reinstalling GRUB from the Rescue System

Boot from the SLES/SLED 10 installation media and select “Rescue System” from the menu.
At the login prompt, enter “root” to access the rescue system.
Run “fdisk -l” to list the partitions on your system. Note the device name of your root partition (e.g. /dev/sda2).
Mount your root partition by running “mount /dev/sda2 /mnt” (replace /dev/sda2 with your actual root partition).
Verify the mount by checking the /mnt/etc/fstab file. You should see your root partition mounted as “/”.
Reinstall GRUB by running “grub-install –root-directory=/mnt /dev/sda” (replace /dev/sda with your actual hard drive device).
Once the command completes successfully, reboot your system by running “reboot”.

After the reboot, your GRUB bootloader should be restored, and you should be able to boot into your SUSE Linux system normally.

Troubleshooting Tips

If the “grub-install” command fails, try using the full path: “/usr/sbin/grub-install –root-directory=/mnt /dev/sda”.
If you have multiple disks or a RAID setup, ensure that all disks have the necessary bootloader partitions (e.g. PReP partition on POWER systems).
If you encounter any other issues, refer to the GRUB man pages for additional options and troubleshooting steps.

Remember to always have a reliable backup of your data before attempting any system repairs or reinstallations.