Iordan, you may be hitting an issue I recently discussed with Neil here: http://www.spinics.net/lists/raid/msg39137.html Please check (using mdadm --examine) whether the drive you are trying to re-add has a valid "Recovery Offset" in the superblock. In other words, the drive was recovering before the reboot. If yes, then this is the issue. Hopefully, we can convince (somebody) to backport it to ubuntu-precise... Alex. On Wed, Jun 13, 2012 at 12:08 AM, Iordan Iordanov <iordan@xxxxxxxxxxxxxxx> wrote: > Hello, > > On Ubuntu 12.04 with a standard kernel (3.2) we've been seeing very strange > behavior with our RAID1 sets, both with superblock 1.2, and with 0.9. The > system has been instructed to come up with a degraded array in initrd, in > case this is relevant. Here is an example of what is happening. We have 5 > RAID1 sets on a server. They live on partitions on /dev/sda and /dev/sdb. > The sever comes up with 2 out of 5 sets degraded, and the others just fine. > > Trying to re-add or add the partitions into the arrays fails like this: > > # mdadm /dev/md2 --re-add /dev/sda6 > mdadm: --re-add for /dev/sda6 to /dev/md2 is not possible > > # mdadm /dev/md2 --add /dev/sda6 > mdadm: /dev/sda6 reports being an active member for /dev/md2, but a --re-add > fails. > mdadm: not performing --add as that would convert /dev/sda6 in to a spare. > mdadm: To make this a spare, use "mdadm --zero-superblock /dev/sda6" first. > > Here is some more information from /proc/mdstat, dmesg, and syslog. > > # cat /proc/mdstat > md2 : active raid1 sdb6[1] > 20479872 blocks [2/1] [_U] > > md3 : active raid1 sdb7[0] > 10239872 blocks [2/1] [U_] > > # dmesg | grep md2 > [ 4.087037] md/raid1:md2: active with 1 out of 2 mirrors > [ 4.087147] md2: detected capacity change from 0 to 20971388928 > [ 4.119168] md2: unknown partition table > [ 12.383035] EXT4-fs (md2): mounted filesystem with ordered data mode. > Opts: (null) > > # dmesg | grep md3 > [ 4.083084] md/raid1:md3: active with 1 out of 2 mirrors > [ 4.083230] md3: detected capacity change from 0 to 10485628928 > [ 4.180986] md3: unknown partition table > [ 9.631814] EXT4-fs (md3): mounted filesystem with ordered data mode. > Opts: (null) > > # ls -l /dev/sda6 > brw-rw---- 1 root disk 8, 6 Jun 12 16:54 /dev/sda6 > # ls -l /dev/sda7 > brw-rw---- 1 root disk 8, 7 Jun 12 16:54 /dev/sda7 > > # grep md2 /var/log/syslog > Jun 12 16:54:32 ps2 kernel: [ 4.087037] md/raid1:md2: active with 1 out > of 2 mirrors > Jun 12 16:54:32 ps2 kernel: [ 4.087147] md2: detected capacity change > from 0 to 20971388928 > Jun 12 16:54:32 ps2 kernel: [ 4.119168] md2: unknown partition table > Jun 12 16:54:32 ps2 kernel: [ 12.383035] EXT4-fs (md2): mounted filesystem > with ordered data mode. Opts: (null) > Jun 12 16:54:38 ps2 mdadm[1181]: DegradedArray event detected on md device > /dev/md2 > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
