[CentOS] Lost all info in a file server because of LVM - HEEEELP ME, please

Hi,

I'm totally desperated.

I have this file server with a total of about 200 GB of my user's files.

The server has "3 in 1" discs, using LVM.

Somehow, i don't know why, the LVM info is gone and i cannot access my 
file system.

I had in LVM:

sda1 -> /boot
sda2 -> /
sda3 -> /home (where all the Samba shares resides).
sda4 -> swap

sdb

sdc

Tha machine now starts with a single partition ( / ) mounted on /dev/root

 From there i can manually mount under /mnt partitions "/boot", "/", but 
NOT "/home".
Trying to mount /home, i always get the busy error.
I cannot unmount the "/" on /dev/root, obviously.

How can i (if possible) restore the LVM info ?

I have a backup from Sunday, so, it's really not a life or death case, 
but nevertheless it is a real annoiance, and the server is already down 
for 24 hours :(

Any help would be apreciated.

Warm Regards,
Mário Gamito