[linux-lvm] LVM groups not visible

["J.L. Blom" <jlblom neuroweave nl>]

Hi,
I'm rather new to LVM and I have a - I think - simple question.
I have a removable disk (USB) with several volumegroups on it created
with one system (linux 2.6.18-1.2200.fc5). I wanted to use it to backup
from another system (linux 2.6.14-386: ubuntu) the W2000 partition.
WHen I connect the disk it is seen as usbdisk on /dev/sda1 and the
content is displayed.
However, lvdisplay says: " no volume groups found"
lvscan says: " no volume groups found"
pvscan says: " no matching physical volumes found"
But the content is visible in nautilus and I can write and read.
Hope somebody can clarify and help me.
Joep