From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hubert Verstraete Subject: Re: problems with faulty disks and superblocks 1.0, 1.1 and 1.2 Date: Mon, 04 Jun 2007 18:43:32 +0200 Message-ID: <46644134.6050404@free.fr> References: <465E9351.2070505@free.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <465E9351.2070505@free.fr> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hubert Verstraete wrote: > Hello > > I'm having problems with a RAID-1 configuration. I cannot re-add a > disk that I've failed, because each time I do this, the re-added disk > is still seen as failed. > After some investigations, I found that this problem only occur when I > create the RAID array with superblocks 1.0, 1.1 and 1.2. > With the superblock 0.90 I don't encounter this issue. > > Here are the commands to easily reproduce the issue > > mdadm -C /dev/md_d0 -e 1.0 -l 1 -n 2 -b internal -R /dev/sda /dev/sdb > mdadm /dev/md_d0 -f /dev/sda > mdadm /dev/md_d0 -r /dev/sda > mdadm /dev/md_d0 -a /dev/sda > cat /proc/mdstat > > The output of mdstat is: > Personalities : [raid1] > md_d0 : active raid1 sda[0](F) sdb[1] > 104849 blocks super 1.2 [2/1] [_U] > bitmap: 0/7 pages [0KB], 8KB chunk > unused devices: > > I'm wondering if the way I'm failing and re-adding a disk is correct. > Did I make something wrong? > > If I change the superblock to "-e 0.90", there's no problem with this > set of commands. > > For now, I found a work-around with superblock 1.0 which consists in > zeroing the superblock before re-adding the disk. But I suppose that > doing so will force a full rebuild of the re-added disk, and I don't > want this, because I'm using write-intent bitmaps. > > I'm using mdadm - v2.5.6 on Debian Etch with kernel 2.6.18-4. > > Bug or misunderstanding from myself? Any help would be appreciated :) > > Thanks > Hubert The kernel 2.6.20 Changelog says: - restarting device recovery after a clean shutdown (version-1 metadata only) didn't work as intended (or at all). That might be my problem, and I confirm 2.6.20.12 is working correctly. Hubert