Booting from USB

[Salvatore De Paolis]

Hi all

I'm having a weird problem while trying to boot from USB pendrive.
My idea is to create a small size distro (kind of DSL) for learning purpose.
I installed grub into the MBR of USB (which as an ext3 partition) and when i
boot on my laptop i get that (hd0,0) is currently the usb pendrive and (hd1,0)
the hard disk.
Kernel seems to be loaded from usb but after that it switch to hard disk and
after it boots, i get the prompt to the hard disk..
Launching again grub from command line i see that (hd0,0) now is the hard disk
and (hd1,0) changed to the usb pendrive.

I tried using device.map (hd0,0) /dev/disk/by-uiid/my_usb_pen_uuid but also
(hd0,0) /dev/sdb but i cant get it to work.

Any hints is apprecciated,
regards
S.