Hi all, I've got a CentOS 6.4 box with a 4-drive RAID level 5 array that died while I was away (so I didn't see the error(s) on screen). I took a fresh drive, did a new minimal install. I then plugged in the four drives from the dead box and tried to re-assemble the array. It didn't work, so here I am. :) Note that I can't get to the machine's dmesg or syslogs as they're on the failed array. I was following https://raid.wiki.kernel.org/index.php/RAID_Recovery and stopped when I hit "Restore array by recreating". I tried some steps suggested by folks in #centos on freenode, but had no more luck. Below is the output of 'mdadm --examine ...'. I'm trying to get just a few files off. Ironically, it was a backup server, but there were a couple files on there that I don't have elsewhere anymore. It's not the end of the world if I don't get it back, but it would certainly save me a lot of hassle to recover some or all of it. Some details; When I try; ==== [root@an-to-nas01 ~]# mdadm --assemble --run /dev/md1 /dev/sd[bcde]2 mdadm: ignoring /dev/sde2 as it reports /dev/sdb2 as failed mdadm: failed to RUN_ARRAY /dev/md1: Input/output error mdadm: Not enough devices to start the array. [root@an-to-nas01 ~]# cat /proc/mdstat Personalities : [raid1] [raid6] [raid5] [raid4] md1 : inactive sdc2[0] sdd2[4](S) sdb2[2] 4393872384 blocks super 1.1 unused devices: <none> ==== Syslog shows; ==== Oct 10 03:19:01 an-to-nas01 kernel: md: md1 stopped. Oct 10 03:19:01 an-to-nas01 kernel: md: bind<sdb2> Oct 10 03:19:01 an-to-nas01 kernel: md: bind<sdd2> Oct 10 03:19:01 an-to-nas01 kernel: md: bind<sdc2> Oct 10 03:19:01 an-to-nas01 kernel: bio: create slab <bio-1> at 1 Oct 10 03:19:01 an-to-nas01 kernel: md/raid:md1: device sdc2 operational as raid disk 0 Oct 10 03:19:01 an-to-nas01 kernel: md/raid:md1: device sdb2 operational as raid disk 2 Oct 10 03:19:01 an-to-nas01 kernel: md/raid:md1: allocated 4314kB Oct 10 03:19:01 an-to-nas01 kernel: md/raid:md1: not enough operational devices (2/4 failed) Oct 10 03:19:01 an-to-nas01 kernel: md/raid:md1: failed to run raid set. Oct 10 03:19:01 an-to-nas01 kernel: md: pers->run() failed ... ==== As you can see, for some odd reason, it says that sde2 thinks sdb2 has failed and tosses it out. ==== [root@an-to-nas01 ~]# mdadm --examine /dev/sd[b-e]2 /dev/sdb2: Magic : a92b4efc Version : 1.1 Feature Map : 0x1 Array UUID : 8be7648d:09648bf3:f406b7fc:5ebd6b44 Name : ikebukuro.alteeve.ca:1 Creation Time : Sat Jun 16 14:01:41 2012 Raid Level : raid5 Raid Devices : 4 Avail Dev Size : 2929248256 (1396.77 GiB 1499.78 GB) Array Size : 4393870848 (4190.32 GiB 4499.32 GB) Used Dev Size : 2929247232 (1396.77 GiB 1499.77 GB) Data Offset : 2048 sectors Super Offset : 0 sectors State : clean Device UUID : 127735bd:0ba713c2:57900a47:3ffe04e3 Internal Bitmap : 8 sectors from superblock Update Time : Fri Sep 13 04:00:39 2013 Checksum : 2c41412c - correct Events : 2376224 Layout : left-symmetric Chunk Size : 512K Device Role : Active device 2 Array State : AAAA ('A' == active, '.' == missing) /dev/sdc2: Magic : a92b4efc Version : 1.1 Feature Map : 0x1 Array UUID : 8be7648d:09648bf3:f406b7fc:5ebd6b44 Name : ikebukuro.alteeve.ca:1 Creation Time : Sat Jun 16 14:01:41 2012 Raid Level : raid5 Raid Devices : 4 Avail Dev Size : 2929248256 (1396.77 GiB 1499.78 GB) Array Size : 4393870848 (4190.32 GiB 4499.32 GB) Used Dev Size : 2929247232 (1396.77 GiB 1499.77 GB) Data Offset : 2048 sectors Super Offset : 0 sectors State : clean Device UUID : 83e37849:5d985457:acf0e3b7:b7207a73 Internal Bitmap : 8 sectors from superblock Update Time : Fri Sep 13 04:01:13 2013 Checksum : 4f1521d7 - correct Events : 2376224 Layout : left-symmetric Chunk Size : 512K Device Role : Active device 0 Array State : AAA. ('A' == active, '.' == missing) /dev/sdd2: Magic : a92b4efc Version : 1.1 Feature Map : 0x1 Array UUID : 8be7648d:09648bf3:f406b7fc:5ebd6b44 Name : ikebukuro.alteeve.ca:1 Creation Time : Sat Jun 16 14:01:41 2012 Raid Level : raid5 Raid Devices : 4 Avail Dev Size : 2929248256 (1396.77 GiB 1499.78 GB) Array Size : 4393870848 (4190.32 GiB 4499.32 GB) Used Dev Size : 2929247232 (1396.77 GiB 1499.77 GB) Data Offset : 2048 sectors Super Offset : 0 sectors State : clean Device UUID : a2dac6b5:b1dc31aa:84ebd704:53bf55d9 Internal Bitmap : 8 sectors from superblock Update Time : Fri Sep 13 04:01:13 2013 Checksum : c110f6be - correct Events : 2376224 Layout : left-symmetric Chunk Size : 512K Device Role : spare Array State : AA.. ('A' == active, '.' == missing) /dev/sde2: Magic : a92b4efc Version : 1.1 Feature Map : 0x1 Array UUID : 8be7648d:09648bf3:f406b7fc:5ebd6b44 Name : ikebukuro.alteeve.ca:1 Creation Time : Sat Jun 16 14:01:41 2012 Raid Level : raid5 Raid Devices : 4 Avail Dev Size : 2929248256 (1396.77 GiB 1499.78 GB) Array Size : 4393870848 (4190.32 GiB 4499.32 GB) Used Dev Size : 2929247232 (1396.77 GiB 1499.77 GB) Data Offset : 2048 sectors Super Offset : 0 sectors State : clean Device UUID : faa31bd7:f9c11afb:650fc564:f50bb8f7 Internal Bitmap : 8 sectors from superblock Update Time : Fri Sep 13 04:01:13 2013 Checksum : b19e15df - correct Events : 2376224 Layout : left-symmetric Chunk Size : 512K Device Role : Active device 1 Array State : AA.. ('A' == active, '.' == missing) ==== Any help is appreciated! -- Digimer Papers and Projects: https://alteeve.ca/w/ What if the cure for cancer is trapped in the mind of a person without access to education? -- 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
