From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx03.extmail.prod.ext.phx2.redhat.com [10.5.110.7]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id oB71DlAN028955 for ; Mon, 6 Dec 2010 20:13:47 -0500 Received: from mail.bmsi.com (www.bmsi.com [24.248.44.156]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id oB71DaGd000926 for ; Mon, 6 Dec 2010 20:13:36 -0500 Received: from melissa.gathman.org (fairfax.gathman.org [72.209.196.211]) (authenticated bits=0) by mail.bmsi.com (8.14.3/8.14.3) with ESMTP id oB71DZg7010497 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 6 Dec 2010 20:13:35 -0500 Message-ID: <4CFD8A3F.8070403@bmsi.com> Date: Mon, 06 Dec 2010 20:13:35 -0500 From: Stuart D Gathman MIME-Version: 1.0 References: <4CFD6563.70508@free.fr> In-Reply-To: <4CFD6563.70508@free.fr> Content-Transfer-Encoding: 7bit Subject: Re: [linux-lvm] A hint on a process Reply-To: 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" To: linux-lvm@redhat.com On 12/06/2010 05:36 PM, Georges Giralt wrote: > Hello ! > I've a system (now on Ubuntu 9.04, but initially on a Fedora ) set up as > follow : > There are two RAID1 software raid arrays (md0 , which is around 100 Mb > and holding an Ext2 FS for use in booting, md1 occupying the rest of the > space used as a PV for LVM) made on a couple of old 160 GB disks. > > On the LVM VG0 are a lot of LV onto which Ubuntu is installed. > > One of the two disks failed. I can't find a 160 GB replacement. Only 320 > Gb for the smallest availlable disk near where I live. > > So I plan to move the system to 320 GB disks and, if possible, not > wasting the 320-160 difference.... > The process I thought about is as follow : > > 1) insert one 320 disk in both arrays (after partitioning it correctly, > 100 Mb for the first partition and the remaining for the second.) > > 2) wait for the raid1 to synchronize. > > 3) mark the remaining 160 GB disk as failed and remove/replace with > another 320 GB disk set up as the first. > > 4) wait for the arrays to reconstruct/synchronize. > > 5) Extend the PV my Volume Group is build on (md1 in this case) > > 6) enjoy a beer... > > What do you think of my method ? Is it a good one or am I missing > something ? You will have understood that losing data is not an option ... > Many thanks in advance for your answers, critics and pointers... > Regards. Your method will fail because the raid superblock is at the end of the partition. I use and recommend this variation: 1. Replace 160 with 320, allocate 2 partitions to match (or slightly exceed if geometry requires) the partitions on the 160. Synchronize. 2. Replace the 2nd 160, resynchronize. 3. Add a 3rd raid1 with the remaining space, and extend the VG with the additional PV. If your system can support 3 drives, you can always partition to mirror everything despite size mismatches. For example, step 3 would become: 3a. reinstall the 160 and allocate 2 80g partitions on the 160 (which is no longer the default boot drive). Allocate an 80g partition on each 320 to mirror the 2 80g partitions giving md2 and md3. Mirror the remaining 80g in each 320 for md4. Extend the VG with the addition 3 PVs.