With my motherboard, I just leave the USB drive plugged, and change a bios setting to boot
from the usb port. (Intel Motherboard D945gnt).
Leslie Satenstein
Message: 14
Date: Tue, 01 Jan 2008 13:12:54 +0000
From: John Austin
Subject: Re: F8 installation in external usb disk (not USB key)
To: For users of Fedora
Message-ID: <1199193174.5598.76.camel@fuerte>
Content-Type: text/plain
On Mon, 2007-12-31 at 12:33 -0600, Mikkel L. Ellertson wrote:
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
--
Hi Mikkel
I liked your way of doing things but when I try on my machine as soon as
I use the map command grub gets in a real muddle.
It is not a problem to me but it should work !!!!!!!!!
Even simple things from the grub command start failing
Eg
I can boot into interactive grub from SATA disk
and re enter grub many times as follows
With SATA=(hd0) USB=(hd1)
(SATA is F8 x86-64, USB is F8 i386) both updated to within 3 days.
Both have /dev/sdx1 = /boot, /dev/sdx2 = /, /dev/sdx3 = swap
root (hd0)
chainloader +1
re-enters the SATA grub menu
root (hd1)
chainloader +1
enters the USB grub menu
root (hd1)
chainloader +1
re-enters the USB grub menu
root (hd0)
chainloader +1
re-enters the SATA grub menu
as soon as I do the following grub falls apart !!!!!!!!!!
root (hd0)
map (hd0) (hd1)
map (hd1) (hd0)
chainloader +1
Interesting ?
John