Please I Need Help Dual booting with two hard drives

[Dragonlive64]

Hello -

I am trying to set up my computer to dual boot with Ubuntu and Windows XP.
In a tutorial I found I was told all I need to do is the following -
-----------------------------------------------------------------------
The problem is that Windows boot must be on the first hard disk/partition in order to boot. You trick it into thinking that by adding those last two lines with the map command in the Grub menu entry.


(The solution is simply adding this to /boot/grub/menu.lst:)

title Windows XP Professional
root (hd1,0)
savedefault
makeactive
chainloader +1
map (hd0) (hd1)
map (hd1) (hd0)

The parts with (hd1,0),(hd0) (hd1) and (hd1) (hd0) depend on where your Windows partition is, which you can find out by typing:

sudo fdisk -l
In this example, Windows is assumed to be on hd1 and Ubuntu on hd0.
-----------------------------------------------------------------------
Alright, I did that but now I am having problems understanding exactly what that output is telling me! I will paste that output below.....

Disk /dev/sda: 20.0 GB, 20020396032 bytes
255 heads, 63 sectors/track, 2434 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x35ac187e

Device Boot Start End Blocks Id System
/dev/sda1 * 1 2327 18691596 83 Linux
/dev/sda2 2328 2434 859477+ 5 Extended
/dev/sda5 2328 2434 859446 82 Linux swap / Solaris

Disk /dev/sdb: 20.0 GB, 20020396032 bytes
255 heads, 63 sectors/track, 2434 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0xec1bc085

Device Boot Start End Blocks Id System
/dev/sdb1 * 1 2327 18691596 7 HPFS/NTFS
/dev/sdb2 2328 2434 859477+ 5 Extended
/dev/sdb5 2328 2434 859446 82 Linux swap / Solaris
-------------------------------------------------------------------------

So now I am not sure which hard drive is which, so I can figure out how to use map correctly! I would appreciate any help that you could provide!

Sincerely
J.E. Elmore

[Herman]

Actually, Windows can be located anywhere, in any partition, on any hard drive and boot, if you know how.

If you have Windows in the fist hard drive, there's no need for the 'map' commands.
Grub's 'map' commands help make it easier for most users to boot Windows on a non-first hard drive because that way you don't need to edit Windows /boot.ini file, which is something most people find a little bit scary.

In most computers you should be able to just run the Ubuntu installer and it will guess the correct hard disk to install the boot loader to and everything will be set up automatically for you.

In a few computers, especially if one hard drive is the IDE type and another is SATA, sometimes the boot loader's pointer gets installed on the wrong MBR by mistake.
If that happens all you need to do is go into your BIOS and switch the hard disks around so the one GRUB was installed to will be the first hard disk. If you do it that way it's very easy and it will be most unlikely that you will need to know any Linux commands or edit any files.

Regards, Herman :D

[Herman]

Disk /dev/sda: 20.0 GB, 20020396032 bytes
255 heads, 63 sectors/track, 2434 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x35ac187e

Device Boot Start End Blocks Id System
/dev/sda1 * 1 2327 18691596 83 Linux
/dev/sda2 2328 2434 859477+ 5 Extended
/dev/sda5 2328 2434 859446 82 Linux swap / Solaris

Disk /dev/sdb: 20.0 GB, 20020396032 bytes
255 heads, 63 sectors/track, 2434 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0xec1bc085

Device Boot Start End Blocks Id System
/dev/sdb1 * 1 2327 18691596 7 HPFS/NTFS
/dev/sdb2 2328 2434 859477+ 5 Extended
/dev/sdb5 2328 2434 859446 82 Linux swap / Solaris:D That looks okay, you have Ubuntu in your first hard disk and Windows in the second hard disk, so you can use the 'map' commands, only put them up higher in the booting stanza, they should come before the 'chainloader' command, because GRUB will run those commands in sequence from the top down, so it's not getting the 'map' commands or it's getting them too late, it has already started booting your Windows boot loader by then.


title Windows XP Professional
root (hd1,0)
savedefault
makeactive
chainloader +1
map (hd0) (hd1)
map (hd1) (hd0)

title Windows XP Professional
root (hd1,0)
map (hd0) (hd1)
map (hd1) (hd0)
savedefault
makeactive
chainloader +1