From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from o.ww.redhat.com (vpn-4-8.stuttgart.redhat.com [10.32.4.8]) by int-mx1.corp.redhat.com (8.12.11.20060308/8.12.11) with ESMTP id k4VLVv1Z001020 for ; Wed, 31 May 2006 17:31:57 -0400 Received: from o.ww.redhat.com (localhost.localdomain [127.0.0.1]) by o.ww.redhat.com (8.13.6/8.13.6) with ESMTP id k4VLVtxF031371 for ; Wed, 31 May 2006 23:31:56 +0200 Received: (from mauelsha@localhost) by o.ww.redhat.com (8.13.6/8.13.6/Submit) id k4VLVsLH031370 for linux-lvm@redhat.com; Wed, 31 May 2006 23:31:54 +0200 Date: Wed, 31 May 2006 23:31:54 +0200 From: Heinz Mauelshagen Subject: Re: [linux-lvm] rescue data after hd crash Message-ID: <20060531213154.GA2236@redhat.com> References: <20060531124546.GF13142@dragonhold.org> Mime-Version: 1.0 Content-Disposition: inline In-Reply-To: <20060531124546.GF13142@dragonhold.org> Reply-To: mauelshagen@redhat.com, LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: LVM general discussion and development vgchange -ay --partial On Wed, May 31, 2006 at 01:45:46PM +0100, Graham Wood wrote: > On Wed, May 31, 2006 at 02:34:04PM +0200, chris wrote: > > I have create a volume group with 4 250GByte harddisks with an ext3 file > > system on the 1TB result. > Stripe or concat? > > > now the third harddisk failed and the volume group is "dead" - obviously. > The way you created the volume had no redundancy - therefore 25% of your data is gone, as > well as the volume's "completeness". > > If you did a concat, then you (with playing) may be able to get some data back from the > first 500GB of the volume - but I wouldn't want to rely on anything that came back from it. > I'd suggest getting hold of 2 identical blank disks, and doing a binary (dd) copy of disks 1 > and 2 to them - and then work on them. You might be able to use vgcfg{backup,restore} to > tell the system that this volume is actually only on 2 disks.... However, anything that > references data > 500GB into the volume is almost definitely lost - because although you've > got 750G-1TB, it's almost all going to be linked back into the section that you've lost. > > If you did a stripe, then you can forget getting any data back off it. You've lost every > 4th block of whatever size you striped on. E.g. with a 64k stripe size, you'll have lost > from 128k-192k, 384k-448k, etc. - and there's almost definitely going to be nothing > salvagable from that. > > Graham > > _______________________________________________ > linux-lvm mailing list > linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ -- Regards, Heinz -- The LVM Guy -- *** Software bugs are stupid. Nevertheless it needs not so stupid people to solve them *** =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Heinz Mauelshagen Red Hat GmbH Consulting Development Engineer Am Sonnenhang 11 Storage Development 56242 Marienrachdorf Germany Mauelshagen@RedHat.com PHONE +49 171 7803392 FAX +49 2626 924446 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-