From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Kraus Subject: mdadm creates corrupt superblock Date: Tue, 28 Oct 2014 19:06:20 +0100 Message-ID: <544FDB1C.5030306@hanswkraus.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: Linux-RAID List-Id: linux-raid.ids Hi, I debugged my problem a bit more: it seems that mdadm creates a defect superblock. That's repeatedly happening, but only for one drive. I copied zeros to that drive (via ddrescue /dev/zero ...) and the drive looks OK. The info I got: ================================================================================================================================================================================================= root@nashorn:/home/kraush/work/smartctrl# mdadm --zero-superblock /dev/sde1 mdadm: Unrecognised md component device - /dev/sde1 root@nashorn:/home/kraush/work/smartctrl# mdadm --add /dev/md126 /dev/sde1 mdadm: add new device failed for /dev/sde1 as 4: Invalid argument root@nashorn:/home/kraush/work/smartctrl# mdadm -E /dev/sde1 /dev/sde1: Magic : a92b4efc Version : 1.2 Feature Map : 0x1 Array UUID : e7caa5d1:b33fd2a5:7782fb0c:9d8d9d5b Name : nashorn:126 (local to host nashorn) Creation Time : Mon Oct 27 15:58:38 2014 Raid Level : raid1 Raid Devices : 2 Avail Dev Size : 1953260976 (931.39 GiB 1000.07 GB) Array Size : 0 Used Dev Size : 0 Data Offset : 262144 sectors Super Offset : 8 sectors Unused Space : before=262056 sectors, after=1953260976 sectors State : clean Device UUID : 4d1420c6:79978477:e86412b1:24beebfc Internal Bitmap : 8 sectors from superblock Update Time : Tue Oct 28 11:53:49 2014 Bad Block Log : 512 entries available at offset 72 sectors Checksum : 6f02d040 - expected 891eedff Events : 0 Device Role : spare Array State : RR ('A' == active, '.' == missing, 'R' == replacing) root@nashorn:/home/kraush/work/smartctrl# ----------------------------------------------------------------------------------------------------------- root@nashorn:/home/kraush/work/smartctrl# cat /proc/mdstat Personalities : [raid1] [raid6] [raid5] [raid4] md127 : active (auto-read-only) raid6 sda1[0] sdk1[6](S) sdl2[7](S) sdh1[5] sdg1[4] sdf1[3] sdc1[2] sdb1[1] 1953017856 blocks super 1.2 level 6, 512k chunk, algorithm 2 [6/6] [UUUUUU] bitmap: 0/4 pages [0KB], 65536KB chunk md10 : active (auto-read-only) raid1 sdi2[0] sdl3[1] 87833408 blocks super 1.2 [2/2] [UU] bitmap: 0/1 pages [0KB], 65536KB chunk md126 : active raid1 sdd1[3] sdj1[2] 488254464 blocks super 1.2 [2/2] [UU] bitmap: 0/4 pages [0KB], 65536KB chunk md0 : active raid1 sdl1[4] sdd2[3] sdi1[5] 156157824 blocks super 1.2 [3/1] [U__] [===================>.] recovery = 95.6% (149290048/156157824) finish=8.4min speed=13496K/sec bitmap: 1/2 pages [4KB], 65536KB chunk unused devices: root@nashorn:/home/kraush/work/smartctrl# ----------------------------------------------------------------------------------------------------------- dmesg: [33299.387382] md: invalid superblock checksum on sde1 [33299.387385] md: sde1 does not have a valid v1.2 superblock, not importing! [33299.387408] md: md_import_device returned -22 root@nashorn:/home/kraush/work/smartctrl# ----------------------------------------------------------------------------------------------------------- root@nashorn:/home/kraush/work/mdadm# mdadm --version mdadm - v3.3-161-gfed12d4 - 21st August 2014 ================================================================================================================================================================================================= Kind regards, Hans