How to recover GRUB Debian Sarge after reinstalling Windows

Posted by serrador on Wed 4 Jan 2006 at 07:36

Many Debian newbies often have to reinstall Windows on the same machine on where Debian is installed. Usually the Windows installation does not take care of our Debian system booting process, overwriting the master boot record with Windows.

To get back our grub first stage boot, here a procedure you can use.

Boot from debian CD choosing linux2.4 kernel (default)
Change to console 2 with alt + F2 keystrokes
Make a new dir to mount the boot partition, for example /disk
mount the root partition on /disk.
Do a chroot to the root partition: issuing chroot /disk
Run grub command to enter grub shell
Type in the root disk for grub, for example root (hd0,1). This is /dev/hda2 on my system
Type the following command to install grub on /dev/hda: setup (hd0).
Last step, type quit, exit from chroot, unmount all disks and reboot

Some notes:

The boot partition is where you put the boot files, normally newbies use only one partition that is mounted on /. Some advanced users store boot files in a separate partition and mount it under /boot. In that case, is the partition that is mounted under /boot the known-to-grub root partition.

Thats all folks!!

This article can be found online at the Debian Administration website at the following bookmarkable URL:

http://www.debian-administration.org/articles/325