[linux-lvm] root on lvm

[Rich Turner <rich storix com>]

i am trying to mount / on a logical volume with reiserfs. my initrd
appears to be loading all of the appropriate modules (lvm-mod, dm-mod,
reiserfs) but i get the following error when the initrd exits and tries
to mount /.

device-mapper: unknown block ioctl 0x5310
sh-2021: reiserfs_read_super: can not find reiserfs on device mapper
(254,1)

is this related to reiserfs or lvm? or my initrd?
using:
lvm-2.00.07
reiserfs-3.6.9-37
suse-9.0
kernel-2.4.21-144-athlon