GRUB -- how to make the secondary drive the primary boot drive

[Thierry de Coulon]

On Wednesday 01 June 2011 07:01:58 Robert Swanson wrote:
> 	I am running Kubuntu 6.06 and I have a problem with grub.  I was
> originally running the system as a multi-boot system.  I had other systems
> on my primary drive, hda, and Kubuntu is on my secondary, hdb.  The
> problem is that my primary drive is dying and I am having a problem
> configuring grub so that I can remove the primary drive and make the
> secondary drive my boot drive. I attempted to install grub on my secondary
> drive, but the problem is that when I pull the primary drive, I can't get
> the system to boot.  I have tried putting the secondary drive on the
> primary cable and it still wouldn't boot. I have a boot partition on hdb
> with what I believe are all the grub files, it is also set as the boot
> drive.
> 	Any help to enable me to successfully remove the primary drive and make
> the secondary my boot drive would be appreciated.  I have all my files
> backed up and am all ready to go.
> Bob

I don't wish to seem insulting but I must ask how your system is build and 
what you know about hardware:

Is your system PATA? "I have tried putting the secondary drive on the primary 
cable and it still wouldn't boot." seems to indicate that yes. Did you set 
this drive as master? "It still wouldn't boot", does that mean you get a GRUB 
error, something like "operating system not found", or what other symptoms?

AFAIK disk priority is not handeld by GRUB, it's handled by your hardware and 
the BIOS.

As a general (PATA) rule I would go this way:
- edit fstab/GRUB to the new /dev/ situation
- set the slave drive as master
- boot with the GRUB Super Disk and start the installed OS
- reinstall GRUB from there on the MBR of the disk

there are alternatives to step 3 such as chrooting from another (possibly 
live) system but I prefer the Grub Super Disk.

Good luck

Thierry