[linux-lvm] vgscan won't recognize my VG

[Andreas Dilger]

David Vidal R. (vidalrod at in.tum.de) writes:
> Linux-version: 2.4.0
> LVM-version: 0.9 (IO-Protocoll 10) -- the version of the Linus stock
> kernel, ie, no patches applied.

What version of user tools do you have?  You should use the beta6 tools.

> pvscan detects all my PVs and adds that they belong to "an unknown VG
> (run vgscan)."
> 
> I runned pvdata -U (get UUIDs) and I got some interesting information
> about my PVs. For simplicity's sake I'll use identifiers for the UUIDs.
> 
> List of UUIDs:
> 
> part5:
> <uuid1>
> <uuid2>
> 
> part7:
> <uuid3>
> <uuid2>
> 
> part2:
> <uuid2>
> <uuid2>

Your UUIDs are broken.  This is why vgscan is failing.  All of them are
incorrect.  Each should list all 3 UUIDs on each disk.  There was a bug
in the user tools related to this, fixed in beta4 (I think).  It is
definitely fixed in beta 6.

> it would be very frustrating to lose 3.2 Gb of data that isn't messed up...

Yes, your data is still on the disk, but it would be safer if you had a
backup.

> Please tell me if you need more information in order to find out what's
> gone wrong.

If you have the new beta6 tools, but an old beta2 kernel, you need to
apply a patch to vg_create_restore.c (I posted it to lvm-devel a week
ago or so), for vgscan to work properly.  If you run vgcfgrestore with
the beta6 tools, it should write the UUIDs to disk properly.

Cheers, Andreas
-- 
Andreas Dilger  \ "If a man ate a pound of pasta and a pound of antipasto,
                 \  would they cancel out, leaving him still hungry?"
http://www-mddsp.enel.ucalgary.ca/People/adilger/               -- Dogbert