From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Robinson Subject: Re: RAID halting Date: Thu, 30 Apr 2009 13:34:25 +0100 Message-ID: <49F99AD1.9090204@anonymous.org.uk> References: <20090430005510167.LLPB6143@cdptpa-omta03.mail.rr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090430005510167.LLPB6143@cdptpa-omta03.mail.rr.com> Sender: linux-raid-owner@vger.kernel.org To: lrhorer@satx.rr.com Cc: 'Linux RAID' List-Id: linux-raid.ids On 30/04/2009 01:55, Leslie Rhorer wrote: >> What I'd be much more inclined to do is create 2 RAID 5 sets, one of 1T >> discs, and one of 1.5T discs, then combine the two using LVM. It just >> feels more natural to me that way. In addition, while both setups will >> tolerate one disc failure, yours will then only tolerate one particular >> one of the remaining 11 failing (the companion drive in the LVM/linear >> pair), and mine will tolerate a failure of any drive on the other RAID-5. > > I had thought of this, but then replacing the 1T + 1.5T pairs with 3T > drives, which I expect to happen eventually, will be more difficult. Not really. You can just replace the drives in one array with 3T ones (one at a time, waiting for the rebuild to complete each time), grow the array, resize LVM's PV with `pvresize`, tell LVM to move the data from the other array across with `pvmove`, decommission the now-empty array/PV, and finally resize the filesystem. If you can have all the drives online at once, it's easier than that - make a new array of 3T drives, add it to the LVM VG, and `pvmove` all your data, decommission the now-empty arrays/PVs, and resize the fs. Or you might choose to keep one of the arrays of smaller drives and have a larger backup system, no `pvmove`s required. Cheers, John.