Hi!
I used a western digital mybookworld (SOHO NAS storage using Linux) as backup for my Linux box. Suddenly, the mybookworld does not boot up any more. So I opened the box, removed the hard disk and put the hard disk into an external USB HDD case, and connected it to my Linux box.
[ 530.640301] usb 2-1: new high speed USB device using ehci_hcd and address 3
[ 530.797630] scsi7 : usb-storage 2-1:1.0
[ 531.794844] scsi 7:0:0:0: Direct-Access WDC WD75 00AAKS-00RBA0 PQ: 0 ANSI: 2
[ 531.796490] sd 7:0:0:0: Attached scsi generic sg3 type 0
[ 531.797966] sd 7:0:0:0: [sdc] 1465149168 512-byte logical blocks: (750 GB/698 GiB)
[ 531.800317] sd 7:0:0:0: [sdc] Write Protect is off
[ 531.800327] sd 7:0:0:0: [sdc] Mode Sense: 38 00 00 00
[ 531.800333] sd 7:0:0:0: [sdc] Assuming drive cache: write through
[ 531.803821] sd 7:0:0:0: [sdc] Assuming drive cache: write through
[ 531.803836] sdc: sdc1 sdc2 sdc3 sdc4
[ 531.815831] sd 7:0:0:0: [sdc] Assuming drive cache: write through
[ 531.815842] sd 7:0:0:0: [sdc] Attached SCSI disk
The dmesg output looks normal, but I was wondering why the hardisk was not mounted at all. And why there are 4 different partitions on it. fdisk showed the following:
root@ubuntu:/home/ubuntu# fdisk /dev/sdc
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): p
Disk /dev/sdc: 750.2 GB, 750156374016 bytes
255 heads, 63 sectors/track, 91201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00007c00
Device Boot Start End Blocks Id System
/dev/sdc1 4 369 2939895 fd Linux raid autodetect
/dev/sdc2 370 382 104422+ fd Linux raid autodetect
/dev/sdc3 383 505 987997+ fd Linux raid autodetect
/dev/sdc4 506 91201 728515620 fd Linux raid autodetect
Oh no! Everything seems to be created as a mdadm software raid. Calling mdadm --examine with the different partitions seems to affirm that.
I think the only partition I am interested in, is /dev/sdc4 (because it is the largest). But nevertheless I called mdadm --examine with every partition.
root@ubuntu:/home/ubuntu# mdadm --examine /dev/sdc1
/dev/sdc1:
Magic : a92b4efc
Version : 00.90.00
UUID : 5626a2d8:070ad992:ef1c8d24:cd8e13e4
Creation Time : Wed Feb 20 00:57:49 2002
Raid Level : raid1
Used Dev Size : 2939776 (2.80 GiB 3.01 GB)
Array Size : 2939776 (2.80 GiB 3.01 GB)
Raid Devices : 2
Total Devices : 1
Preferred Minor : 1
Update Time : Sun Nov 21 11:05:27 2010
State : clean
Active Devices : 1
Working Devices : 1
Failed Devices : 1
Spare Devices : 0
Checksum : 4c90bc55 - correct
Events : 16682
Number Major Minor RaidDevice State
this 0 8 1 0 active sync /dev/sda1
0 0 8 1 0 active sync /dev/sda1
1 1 0 0 1 faulty removed
root@ubuntu:/home/ubuntu# mdadm --examine /dev/sdc2
/dev/sdc2:
Magic : a92b4efc
Version : 00.90.00
UUID : 9734b3ee:2d5af206:05fe3413:585f7f26
Creation Time : Wed Feb 20 00:57:54 2002
Raid Level : raid1
Used Dev Size : 104320 (101.89 MiB 106.82 MB)
Array Size : 104320 (101.89 MiB 106.82 MB)
Raid Devices : 2
Total Devices : 1
Preferred Minor : 2
Update Time : Wed Oct 27 20:19:08 2010
State : clean
Active Devices : 1
Working Devices : 1
Failed Devices : 1
Spare Devices : 0
Checksum : 55560b40 - correct
Events : 9884
Number Major Minor RaidDevice State
this 0 8 2 0 active sync /dev/sda2
0 0 8 2 0 active sync /dev/sda2
1 1 0 0 1 faulty removed
root@ubuntu:/home/ubuntu# mdadm --examine /dev/sdc3
/dev/sdc3:
Magic : a92b4efc
Version : 00.90.00
UUID : 08f30b4f:91cca15d:2332bfef:48e67824
Creation Time : Wed Feb 20 00:57:54 2002
Raid Level : raid1
Used Dev Size : 987904 (964.91 MiB 1011.61 MB)
Array Size : 987904 (964.91 MiB 1011.61 MB)
Raid Devices : 2
Total Devices : 1
Preferred Minor : 3
Update Time : Sun Nov 21 11:05:27 2010
State : clean
Active Devices : 1
Working Devices : 1
Failed Devices : 1
Spare Devices : 0
Checksum : 39717874 - correct
Events : 73678
Number Major Minor RaidDevice State
this 0 8 3 0 active sync
0 0 8 3 0 active sync
1 1 0 0 1 faulty removed
root@ubuntu:/home/ubuntu# mdadm --examine /dev/sdc4
/dev/sdc4:
Magic : a92b4efc
Version : 00.90.00
UUID : febb75ca:e9d1ce18:f14cc006:f759419a
Creation Time : Wed Feb 20 00:57:55 2002
Raid Level : raid1
Used Dev Size : 728515520 (694.77 GiB 746.00 GB)
Array Size : 728515520 (694.77 GiB 746.00 GB)
Raid Devices : 2
Total Devices : 1
Preferred Minor : 4
Update Time : Sun Nov 21 11:05:27 2010
State : clean
Active Devices : 1
Working Devices : 1
Failed Devices : 1
Spare Devices : 0
Checksum : 2f36a392 - correct
Events : 519320
Number Major Minor RaidDevice State
this 0 8 4 0 active sync
0 0 8 4 0 active sync
1 1 0 0 1 faulty removed
If I read the output correctly everything was removed, because it was faulty. Is there ANY way to see the contents of the largest partition? Or seeing somehow which files are broken? I see that everything is raid1 which is only mirroring, so this should be a normal partition. I am anxious to do anything with mdadm, in fear that I destroy the data on the hard disk. I would be very thankful for any help.
