From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Greaves Subject: Re: RAID5 - 2nd drive died whilst waiting for RMA Date: Fri, 12 Nov 2004 12:17:45 +0000 Message-ID: <4194A9E9.70003@dgreaves.com> References: <41948B65.3090504@dgreaves.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <41948B65.3090504@dgreaves.com> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids David Greaves wrote: > So my RAID5 has 2 dead drives and is toasted :( > I had a few smaller disks on another machine which I lvm'ed together > to do a backup - but I could only fit about a quarter of my data > there. I'd *really* like not to have lost all this stuff. > > However I do now have a 'good' drive. > Can I dd the newly dead drive (bear in mind it probably only has a bad > block or two) onto the new drive and come back up in degraded mode? > I've had a think and this is my plan.... comments appreciated. Currently: /dev/md0: Version : 00.90.01 Creation Time : Sat Jun 5 18:13:04 2004 Raid Level : raid5 Array Size : 980446208 (935.03 GiB 1003.98 GB) Device Size : 245111552 (233.76 GiB 250.99 GB) Raid Devices : 5 Total Devices : 4 Preferred Minor : 0 Persistence : Superblock is persistent Update Time : Fri Nov 12 09:46:53 2004 State : clean, degraded Active Devices : 3 Working Devices : 3 Failed Devices : 1 Spare Devices : 0 Layout : left-symmetric Chunk Size : 128K Number Major Minor RaidDevice State 0 0 0 -1 removed 1 8 33 1 active sync /dev/sdc1 2 8 17 2 active sync /dev/sdb1 3 0 0 -1 removed 4 3 65 4 active sync /dev/hdb1 5 8 1 -1 faulty /dev/sda1 UUID : 19779db7:1b41c34b:f70aa853:062c9fe5 Events : 0.4443578 so, the plan in order to try and extract data: * insert new drive as /dev/sdd1 * dd if=/dev/sda1 of=/dev/sdd1 * mdadm /dev/md0 --remove /dev/sda1 * physically swap /dev/sda and /dev/sdd so /dev/sdd * mdadm /dev/md0 --add /dev/sda1 * fsck filesystem and expect to lose files where there were bad blocks * wait for new drive (special delivery - tomorrow morning) * insert new drive as /dev/sdd * mdadm /dev/md0 --add /dev/sdd1 or am I wasting my time? David