From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vincent Schut Subject: Re: looking for advice on raid drives upgrade Date: Wed, 30 Mar 2011 13:22:42 +0200 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 03/30/2011 01:10 PM, Mikael Abrahamsson wrote: > On Wed, 30 Mar 2011, Vincent Schut wrote: > >> - offline the raid, dd(rescue) each 1TB drive onto a new 2TB one, >> replace drives, put raid online again > > This works if you have a superblock version that stores its superblock > in the beginning, not the end (or if you use a partition). This is the > safest. Thanks. That is something I would not have thought about myself. according to mdadm --detail, my superblock version is 1.1: mdadm --detail /dev/md0 /dev/md0: Version : 1.1 Creation Time : Fri Apr 2 11:59:08 2010 Raid Level : raid5 Array Size : 2930287104 (2794.54 GiB 3000.61 GB) Used Dev Size : 976762368 (931.51 GiB 1000.20 GB) Raid Devices : 4 Total Devices : 4 Persistence : Superblock is persistent Update Time : Wed Mar 30 13:17:09 2011 State : clean Active Devices : 4 Working Devices : 4 Failed Devices : 0 Spare Devices : 0 Layout : left-symmetric Chunk Size : 512K Name : fransje:0 (local to host fransje) UUID : 0b2e8a3c:a84a6f4e:31ed60f8:d33de960 Events : 319880 Number Major Minor RaidDevice State 0 8 32 0 active sync /dev/sdc 1 8 16 1 active sync /dev/sdb 3 8 0 2 active sync /dev/sda 4 8 48 3 active sync /dev/sdd Version 1.1 stores the superblock at the beginning of the device, right? So that would allow me to use the dd method? > >> or: >> - manually replace one drive at a time, and let the raid recover and >> thus write the data onto the new drive? > > If you have a bad block anywhere on the degraded drives, you're going to > lose data. > Exactly. A risk I'd like to avoid, of course. Thanks for the info! Vincent.