[plug] How to install grub on an external disk, so it boots as primary.

[Gavin Chester]

On Sat, 2007-07-14 at 08:52 +0800, Mike Holland wrote:
> Hi folks,
> I'm far from home with a CD-less laptop and a USB external drive full of 
> data.
> I have copied Linux and my essential data from laptop to the external
> drive, and wish to make it bootable as a backup, in case the primary fails.
> 
>   However I cannot see how to install GRUB so that it
> can be swapped to the primary drive. Ordinarily, I would boot off
> CD with the new HDD installed, but this laptop has no optical drive,
> and I'm out in the wilderness without another Linux PC to use.
>   The laptop BIOS will not boot from USB-mass-storage.
> 
> So, Is there a way to get grub to install on sdb for booting as sda?
> Or should I try LILO?

This isn't a rebuke to RTFM, but have you read the grub manual? I found
it very comprehensive when I had grub trouble several years ago. Can you
install grub on the primary drive (either in the primary partition or
mbr) to point to the usb drive, or is that not an option? Again, the
grub manual will walk you thru' how to install grub where you want. I
may stand corrected, but I think you can install grub on any partition,
as long as it points to the correct booting partition containing your
kernel. 

Gavin.