[linux-lvm] lvm with raid

[James]

Hello

I am trying to use lvm with a /dev/md0 partition which I believe is
possible. But I miust be missing something. 

Using lvm_0.9, kernel 2.4.0 under debian Linux

I created /dev/md0 (raid autodetect)
Did a pvcreate /dev/md0
lvcreate'd partitions /usr /home /var

copied and remounted everything.
This all goes surprisingly well, until I decided to test with a reboot.

vgscan and vgchange don't find a thing !

test:/home/james# vgscan 
vgscan -- reading all physical volumes (this may take a while...)
vgscan -- no volume groups found

test:/home/james# vgchange -a y
vgchange -- no volume groups found

but if I try to recreate a PV 

test:/home/james# pvcreate /dev/md0
pvcreate -- ERROR: can't initialize physical volume "/dev/md0" of volume
group "devlvm" without -ff
 
Everything is still there apparantly.

I must be missing something fundamental. Thanks fot any help in advance.

James