[ALUG] Boot question

[Chris G]

On Mon, Nov 05, 2007 at 10:01:02AM +0000, Bill Hill wrote:
> Chris G wrote:
> 
> > However what worries me slightly is that there is presumably an MBR
> > (that's what DOS used to call it) on /dev/sda which the BIOS goes to
> > when the system is powered up. If I repartition /dev/sda will I lose
> > this boot record?  How does this get created in the Linux way of doing
> > things?
> 
> Which bootloader are you using?
> Usually grub, which would mean: grub_install /dev/sda

But.....

My existing Fedora installation (using grub as you say) is on /dev/sdb
with /dev/sdb1 being mounted as /boot for grub etc.

So if I (say) completely repartitioned and reformatted /dev/sda would
I lose the MBR that tells the system to boot from /boot on /dev/sdb?
If it wouldn't reboot then I can't run grub.

... and wouldn't "grub-install /dev/sda" expect a boot partition or
something on /dev/sda, there might not be one.

> Lilo, just rerun.
> And there should be a backup in /boot/boot_mbr (or something like that)
> which you could dd if=/boot/boot_mbr of=/dev/sda but only if everything
> else fails and your data's safe on another drive.
> 

None of the documentation I can find tells how the MBR relates to the
rest of the boot process if it's on a different drive.

-- 
Chris Green