[linux-lvm] lvm2 confused about double UUID

[Christian Kujau]

On Sun, 26 Jul 2009 at 21:55, Ron Johnson wrote:
> So the issue seems really the deeper fact that you've got two physical devices
> with the same UUID.  All your lvm issues tumble out from there.
> 
> Is that a good summary?

Yes, that's it. I know, having 2 physical volumes with the same UUID is 
not cool and is certainly not supported, but due to the split that's what 
I have here now and I assumed that I could convince LVM via the filter 
directive to use a certain device for vg02. I mean, vg02 is working fine, 
but I really want to format either sdb or sdc, but I'm afraid of 
destroying something in the LVM layout...

Let me ask another thing: when I assume for a moment that "pvs" is lying 
and really sdc is used for vg02, I'd go ahead and 1) pvcreate sdb, thus 
assigning a new UUID to sdb and 2) remove the filter from lvm.conf. LVM 
should not complain any more (since we have 2 different UUIDs now) and I/O 
still goes to sdc, as it is now apparently. If things go wrong, how can I 
restore the LVM header on sdb? (Would "pvcreate --uuid <old-UUID>" do the 
trick? Or restoring with dd? How many bytes are changed when using 
pvcreate?)

Christian.
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