gargamel:/var/spool# mdadm --version mdadm - v3.2.3 - 23rd December 2011 gargamel:/var/spool# mdadm -a /dev/md1 /dev/sdf2 mdadm: /dev/sdf2 reports being an active member for /dev/md1, but a --re-add fails. mdadm: not performing --add as that would convert /dev/sdf2 in to a spare. mdadm: To make this a spare, use "mdadm --zero-superblock /dev/sdf2" first. gargamel:/var/spool# mdadm --zero-superblock /dev/sdf2 gargamel:/var/spool# mdadm -a /dev/md1 /dev/sdf2 mdadm: added /dev/sdf2 I have this: gargamel:/var/spool# mdadm -q --detail /dev/md1 /dev/md1: Version : 0.90 Creation Time : Sun Jul 25 00:46:56 2010 Raid Level : raid1 Array Size : 1048512 (1024.11 MiB 1073.68 MB) Used Dev Size : 1048512 (1024.11 MiB 1073.68 MB) Raid Devices : 2 Total Devices : 2 Preferred Minor : 1 Persistence : Superblock is persistent Update Time : Fri Nov 2 07:19:36 2012 State : clean Active Devices : 2 Working Devices : 2 Failed Devices : 0 Spare Devices : 0 UUID : c5d9db9e:ea8efce2:5f1e94b5:d63edfe3 Events : 0.318 Number Major Minor RaidDevice State 0 8 82 0 active sync /dev/sdf2 1 8 98 1 active sync /dev/sdg2 shutdown shows: Stopping MD array md1...done (stopped). Boot was like this, and it shows md1 being made out of just one drive but not why. My other 3 md1 arrays re-assemble just fine, just this one does not. kernel: 3.5.3: md: Waiting for all devices to be available before autodetect md: If you don't use raid, use raid=noautodetect md: Autodetecting RAID arrays. md: invalid raid superblock magic on sda1 md: sda1 does not have a valid v0.90 superblock, not importing! md: invalid raid superblock magic on sdb1 md: sdb1 does not have a valid v0.90 superblock, not importing! md: invalid raid superblock magic on sdc1 md: sdc1 does not have a valid v0.90 superblock, not importing! md: invalid raid superblock magic on sdd1 md: sdd1 does not have a valid v0.90 superblock, not importing! md: invalid raid superblock magic on sde1 md: sde1 does not have a valid v0.90 superblock, not importing! md: invalid raid superblock magic on sdf6 md: sdf6 does not have a valid v0.90 superblock, not importing! md: invalid raid superblock magic on sdg6 md: sdg6 does not have a valid v0.90 superblock, not importing! md: Scanned 12 and added 5 devices. md: autorun ... md: considering sdg5 ... md: adding sdg5 ... md: sdg2 has different UUID to sdg5 md: sdg1 has different UUID to sdg5 md: adding sdf5 ... md: sdf1 has different UUID to sdg5 md: created md2 md: bind<sdf5> md: bind<sdg5> md: running: <sdg5><sdf5> bio: create slab <bio-1> at 1 md/raid1:md2: active with 2 out of 2 mirrors md2: detected capacity change from 0 to 6442385408 md: considering sdg2 ... md: adding sdg2 ... md: sdg1 has different UUID to sdg2 md: sdf1 has different UUID to sdg2 md: created md1 md: bind<sdg2> md: running: <sdg2> md/raid1:md1: active with 1 out of 2 mirrors Before I force re-adding sdf2, here's what things look like. gargamel:~# mdadm --examine /dev/sdg2 /dev/sdg2: Magic : a92b4efc Version : 0.90.00 UUID : c5d9db9e:ea8efce2:5f1e94b5:d63edfe3 Creation Time : Sun Jul 25 00:46:56 2010 Raid Level : raid1 Used Dev Size : 1048512 (1024.11 MiB 1073.68 MB) Array Size : 1048512 (1024.11 MiB 1073.68 MB) Raid Devices : 2 Total Devices : 1 Preferred Minor : 1 Update Time : Fri Nov 2 07:32:38 2012 State : clean Active Devices : 1 Working Devices : 1 Failed Devices : 0 Spare Devices : 0 Checksum : 2be1651c - correct Events : 320 Number Major Minor RaidDevice State this 1 8 98 1 active sync /dev/sdg2 0 0 0 0 0 removed 1 1 8 98 1 active sync /dev/sdg2 gargamel:~# mdadm --examine /dev/sdf2 /dev/sdf2: Magic : a92b4efc Version : 0.90.00 UUID : c5d9db9e:ea8efce2:5f1e94b5:d63edfe3 Creation Time : Sun Jul 25 00:46:56 2010 Raid Level : raid1 Used Dev Size : 1048512 (1024.11 MiB 1073.68 MB) Array Size : 1048512 (1024.11 MiB 1073.68 MB) Raid Devices : 2 Total Devices : 2 Preferred Minor : 1 Update Time : Fri Nov 2 07:31:18 2012 State : clean Active Devices : 2 Working Devices : 2 Failed Devices : 0 Spare Devices : 0 Checksum : 2be16511 - correct Events : 318 Number Major Minor RaidDevice State this 0 8 82 0 active sync /dev/sdf2 0 0 8 82 0 active sync /dev/sdf2 1 1 8 98 1 active sync /dev/sdg2 Marc -- "A mouse is a device used to point at the xterm you want to type in" - A.S.R. Microsoft is to operating systems .... .... what McDonalds is to gourmet cooking Home page: http://marc.merlins.org/ -- 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