I was under the impression Fedora 6is supposed to support booting from
external USB drives? It does work, but I had to boot from the rescue CD and
use mkinitrd to create an image with the required modules using the
--preload option for ehci-hcd usb-storage and scsi_mod, otherwise the boot
process would end early on in a kernel panic, unable to mount the root
partition.
I had to do the same to get the systems promise sata controller working,
with the libata and sata_promise modules.
Of course, the first thing I did after this was update the system which
installed kernel 2849. And I had to do the same.
Also interesting was the fact that the 586 kernels installed by default on
the system, even though it is a 3.6 GHz P4 (Alienware M7700 laptop). Any
reason that this would happen? I ended up downloading manually the 686 2849
rpm, uninstalling the 586 version, installing the 686 version, and then
rerunning mkinitrd to get the system to boot properly from the external
drive.
Third time was a charm...