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Re: [LUG] MBR

 

On Tue, Aug 15, 2006 at 09:01:45AM +0100, Terry Hill wrote:
> I solved it quickly by booting with the cd, logging to root and
> running setup/configure and choosing to install lilo on the MBR,
> overwriting the Grub loader.
> 
> I'd assumed that killing the partitions would have killed the MBR, I
> can see now why thats not the case, but was wondering if anyone knew
> of a way to control the contents of the MBR for future reference so
> that I can kill an old grub install if I want to boot from a lilo
> install on a boot partition?

You can't just wipe an MBR, otherwise nothing would work. There has to
be something there. You can backup your current MBR using
dd if=/dev/hda of=/path/to/backup.mbr bs=512 count=1

To install lilo's default MBR, use "lilo -M /dev/hda", I'm not sure
what happens then, but I believe the settings in lilo.conf are written
directly into the MBR (512 bytes on the HDD)

To install dos->windows 98's default MBR (which passes control to the active
partition), run "fdisk /mbr" off a windows/dos boot disk.

Grub's MBR is "Stage 1" of the grub install, it passes control to "stage
2", which reads from menu.lst. It's set when you install grub. You'll
find a copy of it in /boot/grub/stage1 (note 512 bytes)

http://mirror.href.com/thestarman/asm/mbr/GRUB.htm will tell you more
than you could ever know about the MBR.

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