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Date: Tue, 21 Feb 2012 09:40:43 +0100
From: Danilo Godec <danilo.godec@agenda.si>
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Subject: [linux-lvm] Duplicate PV's - how does LVM choose which one to use
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To: LVM general discussion and development <linux-lvm@redhat.com>

Hi,

I had VG's and LV's on top of a Linux MD RAID1 array using two iSCSI 
volumes. Apparently this RAID1 array wasn't started properly after a 
reboot, so LVM detected two duplcate PV's (both RAID1 members had the 
same PV UUID) and chose to use one of them. Unfortunately I didn't 
notice it so it ran like that for a while.

I was lucky and the machine was only rebooted once, so LVM used the same 
PV all the time, but what would happen on a next reboot?

How does LVM decide which one to use?  Will it always choose the same one?


    Thanks, Danilo