SATA Hard disk(Windows) MBR corrupted by IDE hard disk(Linux)

Peter_APIIT · 07-05-2007, 01:51 AM

Hello all LIinux Expert, i have a strange problem where the SATA hard disk MBR is corrupted by Linux Grub Boot loader. When i forgot to set priority of hard disk in BIOS , the MBR of SATA is couurpted by IDE(Linux). Now, the problem is solved but i want to know the reason.

Thanks for your help.

Your help is greatly appreciated by me and others.

b0uncer · 07-05-2007, 01:54 AM

Quote:

When i forgot to set priority of hard disk in BIOS , the MBR of SATA is couurpted by IDE(Linux).

Wasn't it that?

No, really - what did happen exactly? MBR (Main Boot Record) is the first 512 bytes of the harddisk. So..originally on the SATA drive there was something, and then happened something and GRUB did something. Now what are those 'something's? Did GRUB install itself to the SATA drive instead of the IDE drive or what?

A good practise is, when modifying bootloaders, to backup the MBRs of harddisks. It's simply done with dd.

Simon Bridge · 07-05-2007, 02:01 AM

Your statements are contradictory:

1. the SATA hard disk MBR is corrupted by Linux Grub Boot loader
2. the MBR of SATA is couurpted by IDE(Linux)

Which is it?

When you install linux, you are given an option to install GRUB to different places. Normally you would want to install to the MBR of the drive that BIOS will try to boot from. So it is normal for GRUB to write to the MBR.

If a windows recovery disk is used later, it will report (incorrectly) that the MBR has been "corrupted", even declaring that a virus is in there. This is because Windows will assume that it is the only OS on the computer. "Fixing" this with Windows fixboot will break your installation.

I hope this answers your question.

Peter_APIIT · 07-06-2007, 02:07 AM

the problem is ovled now but i want to map the windows partition into grub. How to do so ?

Simon Bridge · 07-06-2007, 04:31 AM

Quote:

the problem is ovled now

Yes, so you said. Can you let us know if any of the replies make sense to you? Otherwise, why should anyone bother?

Quote:

but i want to map the windows partition into grub

There are any number of tutorials and posts about dual boot with GRUB. Read one of those.

For your specific case, we need to know your existing /boot/grub/menu.lst and fdisk -l output.

decrepit · 07-06-2007, 04:55 AM

I agree with Simon, you're not giving us much to go on.
But just in case it helps, here's how my windows is mapped, in /boot/grub/grub.conf

# on /dev/sda1
title Microsoft Windows XP Home Edition
root (hd1,0)
savedefault
makeactive
map (hd0) (hd1)
map (hd1) (hd0)
chainloader +1

Peter_APIIT · 07-07-2007, 12:20 AM

Sorry to do that. Anyway, thanks for your help.