Hi,

I am getting a peculiar output from mdadm that I am having trouble understanding, and looks like it could be incorrect, or at least inconsistent between the two commands.

Some background setup for my configuration is that I am using 5 hard drives. 2 of the hard drives are in raid-0 as device /dev/md0. I also have a raid-5 device that is made up of /dev/md0 and 3 other hard disk partitions.

Below is output of mdadm after assembling the arrays on boot-up.

root@zboll-desktop:/home/zboll# mdadm -D /dev/md0
/dev/md0:
Version : 00.90
Creation Time : Sun Aug 22 15:36:40 2010
Raid Level : raid0
Array Size : 625137152 (596.18 GiB 640.14 GB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 0
Persistence : Superblock is persistent

Update Time : Sun Aug 22 15:36:40 2010
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0

Chunk Size : 64K

UUID : 7c846a89:6700d1f8:3d692fa4:89c397b2 (local to host zboll-desktop)
Events : 0.1

Number Major Minor RaidDevice State
0 8 33 0 active sync /dev/sdc1
1 8 1 1 active sync /dev/sda1

root@zboll-desktop:/home/zboll# mdadm -D /dev/md1
/dev/md1:
Version : 00.90
Creation Time : Sun Aug 22 15:45:26 2010
Raid Level : raid5
Array Size : 1875387648 (1788.51 GiB 1920.40 GB)
Used Dev Size : 625129216 (596.17 GiB 640.13 GB)
Raid Devices : 4
Total Devices : 4
Preferred Minor : 1
Persistence : Superblock is persistent

Update Time : Wed Aug 25 00:33:37 2010
State : active, resyncing
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0

Layout : left-symmetric
Chunk Size : 64K

Rebuild Status : 9% complete

UUID : edf4e42e:e7bc87f6:3d692fa4:89c397b2 (local to host zboll-desktop)
Events : 0.255

Number Major Minor RaidDevice State
0 259 0 0 active sync /dev/md0p1
1 8 17 1 active sync /dev/sdb1
2 8 51 2 active sync /dev/sdd3
3 8 65 3 active sync /dev/sde1

Everything looks reasonable so far. But I am unable to mount the md1 device partition that I was using last night when copying data over. When I run command

root@zboll-desktop:/home/zboll# mdadm --examine /dev/md0
/dev/md0:
Magic : a92b4efc
Version : 00.90.00
UUID : d76330c6:392fe154:3d692fa4:89c397b2 (local to host zboll-desktop)
Creation Time : Sun Aug 22 15:39:09 2010
Raid Level : raid5
Used Dev Size : 625129216 (596.17 GiB 640.13 GB)
Array Size : 1875387648 (1788.51 GiB 1920.40 GB)
Raid Devices : 4
Total Devices : 4
Preferred Minor : 1

Update Time : Sun Aug 22 15:40:04 2010
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0
Checksum : 3f11da80 - correct
Events : 2

Layout : left-symmetric
Chunk Size : 64K

Number Major Minor RaidDevice State
this 0 9 0 0 active sync /dev/block/9:0

0 0 9 0 0 active sync /dev/block/9:0
1 1 8 1 1 active sync /dev/sda1
2 2 8 35 2 active sync
3 3 8 49 3 active sync /dev/sdd1

root@zboll-desktop:/home/zboll# mdadm --examine /dev/md1
mdadm: No md superblock detected on /dev/md1.

The examine and detail statements don't seem to correspond with each other. Does anyone see what I am missing here?

Thanks,
Zack

Nevermind, I misunderstood the output of --examine. What I am seeing makes sense, but I don't know why I can no longer mount the file system.

I have tried

mount /dev/md1p1 /media/raid-5

mount -t ext4 /dev/md1p1 /media/raid-5

Both are failing, I was able to mount the array last night using "mount /dev/md1p1 /media/raid-5" without the need to specify file system type.

below is output for dmesg
root@zboll-desktop:/home/zboll# dmesg | tail
[ 1322.369796] res 51/04:3f:a8:f7:35/00:00:03:00:00/f0 Emask 0x1 (device error)
[ 1322.369802] ata5.00: status: { DRDY ERR }
[ 1322.369806] ata5.00: error: { ABRT }
[ 1322.401868] ata5.00: configured for UDMA/100
[ 1322.401913] ata5: EH complete
[ 2412.006034] md: md0 still in use.
[ 2413.931272] md: md1 still in use.
[ 2427.696655] md: md1 still in use.
[ 2598.966603] md: md1 still in use.
[ 3308.568554] EXT4-fs (md1p1): VFS: Can't find ext4 filesystem


I am worried that I may have lost all of the data I copied over to the md device last night.

I will try mounting again once the file system finishes its resync.

mdadm finished resyncing, but I am still unable to stop the mdadm device, any ideas?

root@zboll-desktop:/media# mdadm --stop /dev/md1
mdadm: fail to stop array /dev/md1: Device or resource busy
root@zboll-desktop:/media# mdadm --stop /dev/md1p1
mdadm: fail to stop array /dev/md1p1: Device or resource busy

root@zboll-desktop:/media# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md1 : active raid5 md0p1[0] sde1[3] sdd3[2] sdb1[1]
1875387648 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU]

md0 : active raid0 sdc1[0] sda1[1]
625137152 blocks 64k chunks

unused devices: <none>




Thanks,
Zack