Rebuild Raid5

Hello,

Recently I lost on my server my raid5, I discovered because the data was partly accessible.

It seems, from the data below, that I lost a drive in december 2012 but did not know that and lost a second one last weekend. This one I noticed because the data was partly accessible. I did shut down the server and disconnected all the hdd’s and connect them again and all 4 were seen by the bios and the md0 worked again because it booted in safe mode. So I have good hope that most of my data is still fine if I make the right rebuild.

when I perform:

mdadm –examine /dev/md1

I got:

/dev/md1:Version : 00.90
Creation Time : Sun Oct 12 18:16:02 2008
Raid Level : raid5
Used Dev Size : 722209984 (688.75 GiB 739.54 GB)
Raid Devices : 4
Total Devices : 2
Preferred Minor : 1
Persistance : Superblock is persistent
Update Time : Fri Jan 17 12:11:13 2014
State : active, FAILED, Not Started
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Events : 3910
Layout : left-symmetric
Chunk Size : 512K
Events : 0.251432
Number Major Minor RaidDevice State
0 0 0 0 removed
1 8 22 1 active sync /dev/sdb6
2 8 38 2 active sync /dev/sdc6
3 0 0 3 removed

and after

mdadm –examine /dev/sda6

I got:

/dev/sda6:Magic : a92b4efc
Version : 00.90.00
UUID :
Creation Time : Sun Oct 12 18:16:02 2008
Raid Level : raid5
Used Dev Size : 722209984 (688.75 GiB 739.54 GB)
Array Size : 2166629952 (2066.26 GiB 2218.63 GB)
Raid Devices : 4
Total Devices : 4
Preferred Minor : 1
Update Time : Sun Dec 30 11:35:30 2012
State : active
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0
Checksum : f38f0a97 – correct
Events : 127013
Layout : left-symmetric
Chunk Size : 64K
Number Major Minor RaidDevice State
this 0 8 6 0 active sync /dev/sda6
0 0 8 6 0 active sync /dev/sda6
1 1 8 22 1 active sync /dev/sdb6
2 2 8 38 2 active sync /dev/sdc6
3 3 8 54 3 active sync /dev/sdd6

and after

mdadm –examine /dev/sdd6

I got:


/dev/sdd6:
Magic : a92b4efc
Version : 00.90.00
UUID :
Creation Time : Sun Oct 12 18:16:02 2008
Raid Level : raid5
Used Dev Size : 722209984 (688.75 GiB 739.54 GB)
Array Size : 2166629952 (2066.26 GiB 2218.63 GB)
Raid Devices : 4
Total Devices : 3
Preferred Minor : 1
Update Time : Fri Jan 10 17:43:59 2014
State : clean
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Checksum : f584d13d – correct
Events : 251427
Layout : left-symmetric
Chunk Size : 64K
Number Major Minor RaidDevice State
this 3 8 54 3 active sync /dev/sda6
0 0 8 6 0 removed
1 1 8 22 1 active sync /dev/sdb6
2 2 8 38 2 active sync /dev/sdc6
3 3 8 54 3 active sync /dev/sdd6

I stopped the array by

mdadm –stop /dev/md1

and perform

mdadm –verbose –create /dev/md1 –chunk=64 –metadate=0.90 –level=5 –raid-devices=4 /dev/sd[a,b,c,d]6
cat /proc/mdstat

gave

Personalities : [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]

md1 : active (auto-read-only) raid5 sdd6[4](S) sdc6[2] sdb6[1] sda6[0]
2166626688 blocks super 0.90 level 5, 64k chunk, algorithm 2 [4/3] [UUU_]
md0 : active raid0 sdd5[3] sdc5[2] sdb5[1] sda5[0]

39069696 blocks 64k chunks

But /fdisk/md1 gives "unknown partition table”

What did I wrong. The raid0 array on the same disks recovered so I have hope to recover most data on the raid5.

Can some one help me out, please
[FONT=Verdana]
[/FONT]