[linux-lvm] LVM data recovery

[Mihai Tanasescu <Mihai Tanasescu skyraven pcnet ro>]

Hello,

I've read the how-to at tldp.org but still can't figure out how to 
recover the data  I have on a LVM setup like this:

/dev/hda + /dev/hdb

/dev/hda has crashed....
I need to recover all data that is on /dev/hdb but vgscan and vgchange 
-ay volume_group_name don't seem to work if /dev/hda is gone

Can anyone help ?
What should I do ?