grub-pc error : no such disk occuring at boot

[flash . 54n]

Hi,

I update grub-legacy to grub2 (ie grub-pc) on debian machine but on machine with
lvm set up, I get a error message just after the hello grub and before the grub
menu (the menu where you chose which system to boot).
The error message is : "Error : no such disk".
The system seem to boot normally except this "error message".

Trying to see what happen, I set up a virtual machine with virtualbox software,
here is the config :

Two virtual 4.5 Go IDE disk (like the trues machines with lvm that cause me
problem except that is 80Go IDE HDD).
Virtual HDD ' setting :
hda1 /boot 100 Mo
hda2 swap 252 Mo
vg00 hda3 and hdb
vg00-lv00 / 512 Mo
vg00-lv01 /tmp 252 Mo
vg00-lv02 /usr 3.5 Go
vg00-lv03 /var 3.5 Go
vg00-lv04 /home "what is left."
(format is ext3 for the whole)

Lenny was installed up to date, following by a grub-pc install and
update-from-grub-legacy (note the error message was already present in grub-pc
chainloaded by grub-legacy). grub-pc 's version is 1.96+20080724-16, the version
comming form Debian Lenny depot.

Extract of config file /boot/grub/grub.cfg (only what can cause havoc is copied
here) :
...
# BEGIN 00_header
...
insmod lvm
set root=(vg00-lv02)
search --fs-uuid --set xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxxxxxxx
if font /share/grub/ascii.pff ; then
set gfxmode = 640x480
insmod gfxterm
insmod vbe
terminal gfxterm
fi
# END 00_header
...
# BEGIN 10_linux
menuentry "Debian GNU/Linux, Linux 2.6.26-2-686" {
set root=(hd0,1)
search --fs-uuid --set yyyyyyy-yyyy-yyyy-yyyy-yyyyyyyy
linux /vmlinuz-2.6.26-2-686 root=/dev/mapper/vg00-lv00 ro
initrd /initrd.img-2.6.26-2-686
}
# Like normal but for single user
menuentry ... (single user mode)" {
...
... ro single
}
# END

I 've tested to modify /etc/defautl/grub, deactivate uuid do nothing and I don't
find info on search command (what this thing do is mystery for me).
note : uuid in grub.cfg is the uuid of the different partition (hda[i],
vg00-lv0[j]).

I 've tested to activate "GRUB_TERMINAL=console", this remove all the line in
00_header's part in /boot/grub/grub.cfg (after update-grub of course) and become
:
# BEGIN 00_header
set default = 0
set timeout = 5
terminal console
# END 00_header

When I reboot with this options, the error message have disapear.

So I put some sleep command to recheck and no more message.

Next, I had the line that was present manually in /boot/grub/grub.cfg (don't do
that because this file will be construct a time or another, it's ok for test
purpose only).
The first line added : insmod lvm, so the header becomes :
# BEGIN 00_header
set default = 0
set timeout = 5
insmod lvm
sleep 5
terminal console
# END 00_header
reboot and the error coming back. So lvm module cause this but why ? I 've
checked /boot/grub/lvm.mod and the file is present, so what ?

Someone pointing out that I lack a line after lvm and before set root commande
something like insmod ext2 :
"insmod lvm
insmod ext2
set root=(hd0,1)"
As the format is ext3, why module ext2 isn't present in my config ? I can't add
it manually because update-grub will remove it, can I ?

I have tried to find some tips on the net but info on grub2 are spartiate.
I need (or I think I need) grub2 because I want to transform this hdd setting on
a raid1 using mdadm with lvm :
/dev/md0 /boot 100 Mo
/dev/md1 swap 252 Mo
vg00 /dev/md2
vg00-lv00 / 512 Mo
vg00-lv01 /tmp 252 Mo
vg00-lv02 /usr 3.5 Go
vg00-lv03 /var 3.5 Go
vg00-lv04 /home "what is left."
With :
md0 = hda1+hdb1
md1 = hda2+hdb2
md2 = hda3+hdb3
This will set a more robust system as I need only far less than 80 Go for my
system and don't want to lose all because of a failled drive.

So anyhelp is welcome, in advance thanks for you help.

Flash Koti
Debian fan