[linux-lvm] How to restore a PV ??

[Jerome]

Hi all,
i've made a mistake on deleting the MBR of a disk who was included in a 
Volume Group of three disks.
Now, when i do a pvdisplay command, i have this result:

  pvdisplay
   2 PV(s) found for VG principal: expected 3
   Logical volume (Database) contains an incomplete mapping table.
   PV segment VG free_count mismatch: 0 != 3576
   PV segment VG extent_count mismatch: 7152 != 10728
   Internal error: PV segments corrupted in principal.

And a vgdisplay show me this following:
vgdisplay
   2 PV(s) found for VG principal: expected 3
   2 PV(s) found for VG principal: expected 3
   Volume group "principal" not found

I'm sure that the data on the hard disk are not erased. But i want to 
restore this third disk, that it is part of the "principal" Volume 
Group. (I have a fourth disk with the same physical caracteristics).
So, how can i do to succeed in this?

Best regards.
-- 
-- Jérôme
Si l'on peut trouver moins que rien, c'est que rien vaut déjà quelque chose.
	(Raymond Devos)