ERROR: could not read device /dev/lvm

[Alex Volkov]

Hello all,
I've installed FAI 3.2.8 on a debian etch and the default config FAIBASE
successfully deploys on a target system. Now, I try to install the same
system using lvm. I'm using class SETUPSTORAGE with the following
example config from Setup-storage wiki:

# Simple LVM example
disk_config sda  bootable:1
primary /boot 500 ext3 rw
primary -       4096-   -       -

disk_config lvm
vg my_pv        sda2
my_pv-_swap     swap    2048    swap    sw
my_pv-_root     /       2048    ext3 rw

Now, when FAI runs, I get the following error message: 

ERROR: could not read device /dev/lvm

Here is context of it:
==========================
xecuting FAIBASE.var
++ FAI_ALLOW_UNSIGNED=1
++ CONSOLEFONT=
++ KEYMAP=us-latin1
++ UTC=yes
++ TIMEZONE=America/Toronto
++ ROOTPW='$1$kBnWcO.E$djxB128U7dMkrltJHPf6d1'
++ MODULESLIST='usbkbd ehci-hcd ohci-hcd uhci-hcd usbhid psmouse'
++ STOP_ON_ERROR=700
++ USE_SETUP_STORAGE=1
Executing SETUPSTORAGE.var
++ USE_SETUP_STORAGE=1
++ debug=1
Loading keymap(s) us-latin1 ...done.
Calling task_action
FAI_ACTION: install
Performing FAI installation. All data may be overwritten!

Calling task_install
Calling task_partition
Partitioning local harddisks
setup_harddisks version 0.42fai
Probing disks:  /dev/sda
Disks found: sda

Using config file: /var/lib/fai/config/disk_config/SETUPSTORAGE
ERROR: could not read device /dev/lvm
setup_harddisks version 0.42fai
Probing disks:  /dev/sda
Disks found: sda

==========================

After the setup drops into the shell, all the lvm configuration commands
such as pvs. pvcreate, vgcreate are available and I could use them to
configure lvm manually.

Also I tried to add mknod /dev/lvm c 109 0 
to 20-hwdetect.source, as mentioned here:
http://pigeonsnest.co.uk/stuff/lvm-root/lvm-root.html
but even when the device node is create I'm getting the same error.

Any help is appreciated,

Alex.