On Fri, 6 Jul 2012 12:09:43 -0400 Alex <mysqlstudent@xxxxxxxxx> wrote: > Hi, > > I had a situation where after rebooting all three drives of a RAID5 > array were marked as spares. I rebuild the array using "mdadm -C > /dev/md1 -e 1.1 --level 5 -n 3 --chunk 512 --assume-clean /dev/sda2 > /dev/sdb2 /dev/sdc2" and mdstat showed it was again assembled. The > filesystem types on /dev/sdb were all "Linux" instead of "Linux raid > autodetect", so I changed them back. You've been bitten by http://neil.brown.name/blog/20120615073245 So md1 is all happy again is it? > > /dev/md2 also has a problem, and I have no idea what to do there either. > > When I tried to fsck it to be sure it was intact, it prompted me that > there was a problem with the superblock, and I answered Yes to "Fix?". Always use "fsck -n" to check if something is intact!! > > After there being a number of further errors, I quit fsck, and am here for help. > > Did I perhaps assemble the array in the wrong disk order? Is there > another superblock that may be useful here and how would I find it? Certainly possible. With only 3 devices there aren't may different orders to test so you could try them all. As fsck thought it recognised a filesystem it is very likely that the first device is correct, so just try swapping the other to and issuing a new --create command. Then "fsck -n". NeilBrown > > I'm really concerned that I've lost the data and really hope someone > has some ideas. > > # cat /proc/mdstat > Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] > [raid4] [raid10] > md1 : active raid5 sda2[0] sdc2[2] sdb2[1] > 51196928 blocks super 1.1 level 5, 512k chunk, algorithm 2 [3/3] [UUU] > > md2 : active raid5 sdc3[0] sdb3[2] sda3[1] > 1890300928 blocks super 1.1 level 5, 512k chunk, algorithm 2 [3/3] [UUU] > > md0 : active raid1 sdc1[0] sdb1[1] > 255988 blocks super 1.0 [3/2] [U_U] > > unused devices: <none> > > # mdadm -E /dev/md1 > mdadm: No md superblock detected on /dev/md1. > > # mdadm --detail /dev/md1 > /dev/md1: > Version : 1.1 > Creation Time : Fri Jul 6 13:41:54 2012 > Raid Level : raid5 > Array Size : 51196928 (48.83 GiB 52.43 GB) > Used Dev Size : 25598464 (24.41 GiB 26.21 GB) > Raid Devices : 3 > Total Devices : 3 > Persistence : Superblock is persistent > > Update Time : Fri Jul 6 16:01:18 2012 > State : clean > Active Devices : 3 > Working Devices : 3 > Failed Devices : 0 > Spare Devices : 0 > > Layout : left-symmetric > Chunk Size : 512K > > Name : sysresccd:1 (local to host sysresccd) > UUID : 4ce6925e:b6cbd20e:7f3efbfc:668295fe > Events : 2 > > Number Major Minor RaidDevice State > 0 8 2 0 active sync /dev/sda2 > 1 8 18 1 active sync /dev/sdb2 > 2 8 34 2 active sync /dev/sdc2 > > Thanks for any ideas, > Alex > -- > 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
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