[Grml] booting from external disk

[August C. Quint]

Hi,

I'm looing for a Linux-system that can boot from an USB-hard-disk. Via a 
Google I found Grml. But I have some problems with this. So please allow me 
to describe the system, the problems etc.

My system: Aldi offered a notebook in may 2006 and I bought one. This is my 
system, if you need more information about it let me know.

What I did: I downloaded the grml.iso-file via grml.gwendoline.at, burned a Cd 
and started the notebook: works, fine. I added my external hard-disk via USB 
( I removed the internal hard-disk for safety, I want to keep the installed 
XP) and installed the software via grml2hd: works, fine.

For a test I stopped the machine, removed the CD and started it again. In the 
BIOS I've checked 'boot from USB-device' already and voila: it worked.

The next day I wanted to do this again: problems. So please allow me to 
describe my problems.

problem #1: the inital screen comes up with the 3 choices. By doing nothing 
the choice 'grml' was started. Next was a scrren with the text: loading 
2.6.18-grml, followed by approx. 180 dots (takes 10 minutes or so). What's 
this?
At the end of this a message was displayed: BIOS data check succesfull (or 
something similar).

Now we come to the booting-process. This works, a lot of lines are running on 
the screen. But we come to
problem #2: a message appears:
usb 2-2: reset high speed USB device using ehci_hcd and address 2
This will be repeated multiple times, some other messages are appearing and 
these messages appear over and over again. One of the messages between is:
SCSI-error, return-code = 0x00050000

What's this?

Can you please give me a hint.
Thanks.
AugustQ

PS: on my desktop-machine I can easily switch operating system by removing the 
hard-disk (power off). I'm looking for a similar solution for my notebook. 
Opening a bay and swapping the disk is possible but I don't want it this way.