From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <3AE6BA27.1FC18A3C@in.tum.de> Date: Wed, 25 Apr 2001 13:51:03 +0200 From: David Vidal Rodriguez MIME-Version: 1.0 Subject: Re: [linux-lvm] Problem with UUID, vgscan, vgcfgrestore References: <200104022100.f32L0jL13101@webber.adilger.int> <01040307345000.00915@darkvader> Content-Transfer-Encoding: 7bit Sender: linux-lvm-admin@sistina.com Errors-To: linux-lvm-admin@sistina.com Reply-To: linux-lvm@sistina.com List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: List-Id: Content-Type: text/plain; charset="us-ascii" To: linux-lvm@sistina.com Oh yes, this procedure has helped me too! I had the same problem and now I can use my VG with no single byte being lost. But from now on I'll start making backups of my data... :) Thanks! > > OK, I have figured out why vgcfgrestore doesn't work properly with broken > > UUIDs. It is because vgcfgrestore only restores the backup VGDA data to > > each disk separately. This means it is not possible to have consistent > > UUIDs generated for all PVs in a VG when vgcfgrestore is run. > > > > You can try the following (experimental) procedure to fix the UUIDs: > > > > Check each PV with "pvdata -PP /dev/hdX" to ensure it has a valid > > UUID assigned. Also get the PV numbers (starting with 1) for each of > > the PVs. Finally, check the pv_uuidlist_on_disk.base for each PV. > > It will normally be 6144, but it does not have to be. > > > > for each PV (in PV# order) > > dd if=/dev/hdX bs=1 skip=44 count=128 >> /tmp/uuids > > > > This should create a file /tmp/uuids which has all of the PV UUIDs in it. > > Make sure there are as many UUIDs in the file ("od -a /tmp/uuids" is good) > > as you have PVs (8 in your case). > > > > Now, we want to write the UUID list back to the PVs so vgscan is happy: > > > > for each PV (in any order) > > dd if=/tmp/uuids of=/dev/hdX bs=1 seek= > hdX> > > Unfortunately this doesn't work. I get on of=/dev/hda2 an invalid argument. > Can you write to a partition with dd ? Or has it to be a disk such as > /dev/hda ? > > > > > example: > > dd if=/tmp/uuids of=/dev/hda2 bs=1 seek=6144 > > > > Now vgscan should be able to detect all of the disks and work properly. > > > > Cheers, Andreas > > _______________________________________________ > linux-lvm mailing list > linux-lvm@sistina.com > http://lists.sistina.com/mailman/listinfo/linux-lvm -- ------------------------------------------------------------------------ David Vidal R. (vidalrod@in.tum.de) http://dvr.ismad.com "Ein Computer ohne Windows ist wie ein Fisch ohne Fahrrad."