From mboxrd@z Thu Jan 1 00:00:00 1970 From: Troy Telford Subject: RAID-6 disk superblock issue Date: Tue, 13 Dec 2011 15:42:20 -0700 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7BIT Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids I have a RAID-6 array I'm having trouble with: md2 : active raid6 sdl1[6] sdh1[0] sdm1[5] sdk1[3] sdj1[2] sdi1[1] 1953535488 blocks level 6, 128k chunk, algorithm 2 [6/5] [UUUU_U] [>....................] recovery = 0.0% (27164/488383872) finish=599.1min speed=13582K/sec - When the system boots (or when I attempt to build the array), I get a message that /dev/sdl and /dev/sdl1 have the same superblock, and that I should zero one. - So, I zero the superblock using 'mdadm --zero-superblock /dev/sdl (or /dev/sdl1; doesn't matter which I use). - I then re-add the device to the array (and the RAID-6 array recovers, as above.) - The next time I boot, I get the exact same error message. - It doesn't seem to matter which (between the device or the partition) that I zero the superblock on. I get the same error message at boot (when the drive is being assembled). - Since it's redundant data anyway, I've tried dd'ing from /dev/zero over the drive, repartitioning the drive, and then adding the drive to the array. Same behavior. - My mdadm.conf just has the array itself, and the array's UUID. It doesn't explicitly list devices. So what am I missing? There's got to be a way I can get the array to assemble at boot, instead of having to manually --zero-superblock every time. -- Troy Telford