Grub - Nuts n Boldt

What is GRUB

Grub is an insect that eats my yard and is only useful for fish bait. It is also the Boot loader installed by Ubuntu.

Topics

You Install Ubuntu but Windows is not a boot option.

I have just installed Ubuntu on my primary master drive. How do i set it up so i can choose at start-up what OS to load? Is it just a matter of adding some stuff to grub?

Yes its just a matter of adding an entry to menu.lst...

Open Applications > Accessories > terminal
Backup
sudo cp /boot/grub/menu.lst /boot/grub/menu.lst-b
Edit
gksudo gedit /boot/grub/menu.lst
Add following below line
### END DEBIAN AUTOMAGIC KERNELS LIST

   
title Win XP Home
      rootnoverify (hd0,0)
      makeactive
      chainloader +1
      boot

OR Add this if Linux is on the 1st drive and Windows is on the second

   
title Win XP Home
      map (hd0) (hd1)
      map (hd1) (hd0)
      rootnoverify (hd1,0)
      makeactive
      chainloader +1
      boot

Make XP the default opperating system

Open Applications > Accessories > terminal
Backup
sudo cp /boot/grub/menu.lst /boot/grub/menu.lst-b
Edit
gksudo gedit /boot/grub/menu.lst
Copy the XP menu entry and find the line that reads
### BEGIN AUTOMAGIC KERNELS LIST
then paste the XP entry just before that line

Configfile and Chainloader Entries

You have a 2^nd Linux distro you want to install. Install its boot loader pointer in the boot sector of its root partition
Now add an entry in the 1^st Linux distro /boot/grub/menu.lst - Adjust (hd#,#) to fit your installation.
Configfile
title Linux Distro 2 on /dev/sda3
configfile (hd0,2)/boot/grub/menu.lst
Chainload
title Linux Distro 2 on /dev/sda3
root (hd0,2)
chainloader +1

Live CD - Mount hard drive partition for edit

sudo mkdir /mnt/root

sudo mount -t ext3 /dev/hda1 /mnt/root

Master Boot Record

The MBR and Dual Booting go hand in hand. The MBR occupies the first 512 bytes of a hard drive (or any other disk drive for that matter) and has three parts:

The boot code which is 446 bytes long. When you see install GRUB to the MBR This is the area of disk that the GRUB install writes a little bit of code to. What this code does is execute the program /boot/grub/stage2
The partition table which is 64 bytes long
The boot code signature of hex(55aa) which is 2 bytes long and goes at the very end

Grub Links

How to restore Grub from a live Ubuntu cd. This will restore grub if you already had grub installed but lost it to a windows install or some other occurence that erased/changed your MBR so that grub no longer appears at start up or it returns an error.
Super Grub Disk is a bootable cdrom, usb or floppy specially designed for the restore of boot.
GNU GRUB - Wikipedia, the free encyclopedia
Illustrated Dual Boot Site Good stuff here.

Nuts n Boldt on Grub