usb hard disk

[Zoran Kolic]

Dear all!
This is not strictly "stable", unless I make a mistake and shoot myself
in the foot.
I have 6.2 amd64 with mobo asus k8n nforce3 250. This box I'd like to
use as host for usb hdd, that should contain linux install (debian 4.0,
when comes out). Two worlds have not to interfare in any meaning. I hesi-
tate to take internal freebsd hdd out of the box. Here's the plan:
plug external hdd to usb, change bios option to boot from cd, install
debian on sda, change bios option to boot from usb disk. Lilo or grub
should be installed on external disk, without writing any data on inter-
nal hdd. Is it possible at all?
I'm aware that partition table on external hdd could have data for freebsd
disk, but nothing has to be writen on internal disk. No boot manager
needed, all has to be done using bios. What obstacle would I see doing
that? When usb hdd goes away, I want my freebsd system as I have it now.
And... I don't like the idea to add hdd inside the box, as slave.
I'd like to hear hints, not to have linux mbr on internal (sata) disk,
or any adage to it.
Best regards

                                      Zoran