[CentOS] How to move my MBR

Fri May 23 13:51:32 UTC 2008
Scott Moseman <scmoseman at gmail.com>

> The BIOS determines which disk (the first) will be chosen to boot from.

I have no problems configuring the boot order in the BIOS.

I must have the MBR on /dev/hdc (which is being removed).
The /boot partition is on /dev/sda (where I want to move MBR).

> To make a plain bootsector copy:
> dd if=/dev/sda of=/dev/sdb bs=512 count=1

sda = old MBR source and sdb = new MBR source, I assume?
So, in my instance, I'm going to want to run it in this syntax:

dd if=/dev/hdc of=/dev/sda bs=512 count=1

I'm assuming the first 512 bytes are allocated purely for MBR and
won't hold any data that could be overwritten?  Would that be true?

> grub
> root (hd0,1)   # press tab for command completion
> setup (hd0)

Do I need to move the MBR, remove the old drive, and reboot from
a LiveCD in order to have a reconfigure of grub correctly see which
drive it should find to boot from?  Or can I do this before taking the
system down for the drive removal?