GRUB error 16

Today I had a problem with one of our computers. It did not want to boot. The boot loader is called GRUB. Most Linux distributions now use GRUB which is much more advanced than LILO and some other boot loaders.

GRUB is great for several reasons:

• It is rather easy to setup (except for the drive number that is not the conventional number under the Linux operating system); and
• You can modify the configuration file with a simple text editor without the need to re-run any command for the modifications to be taken in account.

I do not recall having any major problems with GRUB except when trying to also install MS-Windows. Here, the problem is that MS-Windows automatically installs its own Master Boot Record (MBR) since it does not expect a computer to have multiple Operating Systems installed. Needless to say, Microsoft does not support a computer that dual boots with Linux. I have once created a boot drive with 5 OSes: Win98, Win2k, WinXP, FedoraCore and an old Red Hat. This has been useful since different software can be used on different OSes but not all.

Now, I am not too sure why my system stopped working. I had it booted under FedoraCore to update my CVS/SVN repositories, then my kids used Win98. This morning, it did not want to boot at all.

To fix the problem I used an Ubuntu installation disk that includes a Rescue option. This Rescue option starts a Linux Kernel from the CDROM and opens a shell after an automatic chroot to your root drive. If I’m correct, this exists since version 6.10. Inside that shell, I ran grub-install /dev/hda and when I rebooted, it worked just fine.