John Austin wrote:
The only real decisions are to do with how to boot.
If the USB disk is to rely on the MBR of a main SATA/IDE type disk then
choose the /dev/sdxy device associated with the USB disk at install
time.
Then add an entry to grub.conf on the fixed disk.
title USB disk
root (hdp,q)
chainloader +1
In addition after install I would then configure grub on the MBR of the
USB disk as well such that I can boot the disk with and without the
presence of the "main", "fixed" disk.
What I did was install a copy of Grub to the MBR of the USB drive,
and then create an entry like this in the SATA Grub menu:
title USB disk
root (hd0)
map (hd0) (hd1)
map (hd1) (hd0)
chainload +1
Because of the map commands, the USB drive is hd0 when the chainload
command is executed, and it loads Grub from the USB drive. (hd0 is
the entire disk, starting from the MBR.) From there it is the same
as if you had used the BIOS option to boot from the USB drive. The
only thing you have to be careful of is if you have more then one
USB drive plugged in. You will get a Grub error is the wrong one is
detected first, and does not have a boot loader on it.
Mikkel
--
Do not meddle in the affairs of dragons,
for thou art crunchy and taste good with Ketchup!