I have (*ahem had) a raid 5 setup with four 500GB SATA hard drives for storage. I rebooted the machine and it did not mount the raid drive.
Short Version: mdstat says I only have 2/4 working drives, but it looks like I have 3/4 (at least) working drives.
Long Version:
So I checked mdastat
Code:
>sudo cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4]
md0 : inactive sdc1[1](S) sdd1[2](S)
976767872 blocks
unused devices: <none>
and that was odd so I tried to use mdadm
Code:
>sudo mdadm -As /dev/md0
mdadm: /dev/md0 assembled from 2 drives - not enough to start the array.
Then I thought that 2(!) drives out of the 4 failed, no way since I just bought them and it is been working for about 4 days now. So then I used sfdisk for each of the four drives
Code:
>sudo sfdisk -l /dev/sdb
Disk /dev/sdb: 60801 cylinders, 255 heads, 63 sectors/track
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0
Device Boot Start End #cyls #blocks Id System
/dev/sdb1 0 - 0 0 0 Empty
/dev/sdb2 0 - 0 0 0 Empty
/dev/sdb3 0 - 0 0 0 Empty
/dev/sdb4 0 - 0 0 0 Empty
>sudo sfdisk -l /dev/sdc
Disk /dev/sdc: 60801 cylinders, 255 heads, 63 sectors/track
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0
Device Boot Start End #cyls #blocks Id System
/dev/sdc1 0+ 60800 60801- 488384001 83 Linux
/dev/sdc2 0 - 0 0 0 Empty
/dev/sdc3 0 - 0 0 0 Empty
/dev/sdc4 0 - 0 0 0 Empty
>sudo sfdisk -l /dev/sdd
Disk /dev/sdd: 60801 cylinders, 255 heads, 63 sectors/track
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0
Device Boot Start End #cyls #blocks Id System
/dev/sdd1 0+ 60800 60801- 488384001 83 Linux
/dev/sdd2 0 - 0 0 0 Empty
/dev/sdd3 0 - 0 0 0 Empty
/dev/sdd4 0 - 0 0 0 Empty
>sudo sfdisk -l /dev/sde
Disk /dev/sde: 60801 cylinders, 255 heads, 63 sectors/track
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0
Device Boot Start End #cyls #blocks Id System
/dev/sde1 0+ 60800 60801- 488384001 83 Linux
/dev/sde2 0 - 0 0 0 Empty
/dev/sde3 0 - 0 0 0 Empty
/dev/sde4 0 - 0 0 0 Empty
and we see that there is something wrong with /dev/sdb (where did you go?).
But when I try to start up the device (because it looks like I have 3 working) I get the same error that there are only 2 drives available.
So then I tried to use mdadm again and got:
Code:
>sudo mdadm -E /dev/sdb1
mdadm: cannot open /dev/sdb1: No such file or directory
nhomer@ubuntu-desktop:~$ sudo mdadm -E /dev/sdc1
/dev/sdc1:
Magic : a92b4efc
Version : 00.90.00
UUID : a5dcb6ff:0d931c7f:bb855af7:201184b4 (local to host ubuntu-desktop)
Creation Time : Sun Sep 9 22:14:31 2007
Raid Level : raid5
Device Size : 488383936 (465.76 GiB 500.11 GB)
Array Size : 1465151808 (1397.28 GiB 1500.32 GB)
Raid Devices : 4
Total Devices : 3
Preferred Minor : 0
Update Time : Thu Sep 13 01:43:04 2007
State : clean
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Checksum : e31dd26f - correct
Events : 0.28452
Layout : left-symmetric
Chunk Size : 64K
Number Major Minor RaidDevice State
this 1 8 33 1 active sync /dev/sdc1
0 0 0 0 0 removed
1 1 8 33 1 active sync /dev/sdc1
2 2 8 49 2 active sync /dev/sdd1
3 3 8 65 3 active sync /dev/sde1
>sudo mdadm -E /dev/sdd1
/dev/sdd1:
Magic : a92b4efc
Version : 00.90.00
UUID : a5dcb6ff:0d931c7f:bb855af7:201184b4 (local to host ubuntu-desktop)
Creation Time : Sun Sep 9 22:14:31 2007
Raid Level : raid5
Device Size : 488383936 (465.76 GiB 500.11 GB)
Array Size : 1465151808 (1397.28 GiB 1500.32 GB)
Raid Devices : 4
Total Devices : 3
Preferred Minor : 0
Update Time : Thu Sep 13 01:43:04 2007
State : clean
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Checksum : e31dd281 - correct
Events : 0.28452
Layout : left-symmetric
Chunk Size : 64K
Number Major Minor RaidDevice State
this 2 8 49 2 active sync /dev/sdd1
0 0 0 0 0 removed
1 1 8 33 1 active sync /dev/sdc1
2 2 8 49 2 active sync /dev/sdd1
3 3 8 65 3 active sync /dev/sde1
>sudo mdadm -E /dev/sde1
/dev/sde1:
Magic : a92b4efc
Version : 00.90.00
UUID : a5dcb6ff:0d931c7f:4bc81c71:77d10fa7
Creation Time : Sun Sep 9 22:14:31 2007
Raid Level : raid5
Device Size : 488383936 (465.76 GiB 500.11 GB)
Array Size : 1465151808 (1397.28 GiB 1500.32 GB)
Raid Devices : 4
Total Devices : 3
Preferred Minor : 0
Update Time : Thu Sep 13 01:43:04 2007
State : clean
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Checksum : cb201f00 - correct
Events : 0.28452
Layout : left-symmetric
Chunk Size : 64K
Number Major Minor RaidDevice State
this 3 8 65 3 active sync /dev/sde1
0 0 0 0 0 removed
1 1 8 33 1 active sync /dev/sdc1
2 2 8 49 2 active sync /dev/sdd1
3 3 8 65 3 active sync /dev/sde1
Basically at this point I am open to any suggestions (I don't want to have to reload ~1 TB of data please). How do I get this working and am I even on the right track?
Did you have an answer or find a solution ?
