From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Boman Subject: Re: Failed during rebuild (raid5) Date: Sun, 05 May 2013 13:16:31 -0400 Message-ID: <518693EF.6090802@midgaard.us> References: <51839E4F.7050102@midgaard.us> <51866602.8000704@midgaard.us> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <51866602.8000704@midgaard.us> Sender: linux-raid-owner@vger.kernel.org To: Ole Tange Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 05/05/2013 10:00 AM, Andreas Boman wrote: > On 05/03/2013 08:26 AM, Ole Tange wrote: >> On Fri, May 3, 2013 at 1:23 PM, Andreas Boman >> wrote: >> >>> This morning I came up to see the array degraded with two missing >>> drives, >>> another failed during the rebuild. >> I just started this page for dealing with situations like yours: >> https://raid.wiki.kernel.org/index.php/Recovering_a_failed_software_RAID >> >> >> /Ole > > After having ddrescue running all night, it dropped to copying at a > rate of 512B/s. I interrupted it and restarted, it stays at that > speed. shows no errors: > > Press Ctrl-C to interrupt > Initial status (read from logfile) > rescued: 557052 MB, errsize: 0 B, errors: 0 > Current status > rescued: 1493 GB, errsize: 0 B, current rate: 512 > B/s > ipos: 937316 MB, errors: 0, average rate: 16431 > kB/s > opos: 937316 MB, time from last successful read: > 0 s > Copying non-tried blocks... > > > However that is much too slow... > > Then, I decided to take a look at the superblocks and to my horror > discovered this: > > # mdadm --examine /dev/sd[b-g] >>raid.status > mdadm: No md superblock detected on /dev/sdb. > mdadm: No md superblock detected on /dev/sdc. > mdadm: No md superblock detected on /dev/sdd. > mdadm: No md superblock detected on /dev/sde. > mdadm: No md superblock detected on /dev/sdf. > mdadm: No md superblock detected on /dev/sdg. > > Can I recover still? What is going on here? > > Thanks, > Andreas > Turns out the superblocks are there. I ran --examine on the disk instead of partition. OOps. I still have the problem with ddrescue being very slow, it is running at 512 B/s pretty much no matter what options I use. The ddrescued disk does NOT have a md superblock. I tried to ddrescue -i to skip and grab the last 3MB or so of the disk, that seemed to work, but I still don't have the superblock. How do I find/recover the superblock from the original disk? After that is done I'll try to get the array up with 4 disks, then add the spare and have it rebuild. After that I'll add a disk to go to raid 6. Thanks, Andreas