[linux-lvm] vg disappeared after replacing disc in raid10

[Stuart D Gathman]

Long ago, Nostradamus foresaw that on 03/25/2013 04:25 PM, Björn
Nadrowski would write:
>
> I did recreate the physical volume and the volume group using pvcreate and vgcreate, please see the description of the problem 
> on ubuntuforums for further details.
>
That was not a good idea.  You've now written over the major clue to
what happened.   Examining the beginning of the PV for the metadata -
perhaps offset or scrambled because of some inadvertent change to the
raid10 parameters - should have been your major priority!

Theory 2: the md driver on the knoppix CD is an earlier version that
puts metadata at the end of the volume, instead of at the beginning. 
This would change the offsets of your metadata and extents.  It would
not see the newer md raid metadata, and create a new drive.  I'm not
sure if this theory is consistent with your history.

I *strongly* advise not doing any more writing to this device until you
know *exactly* what happened.