How To Access RAID Disks From Another Device?

[kindastuck]

I have a faulty NAS which has been running RAID 1. I need to extract the data from the disks (it is the NAS device itself that has failed, not the disks). I removed the disks and put them into a PC which I then booted up with Ubuntu 12.04 LiveCD. It can see the disks (through disk utility) but will not start the RAID array. The error message simply says "not enough components available to start the RAID array".

I'm a Ubuntu newbie and don't know which direction to turn in. Can somebody point me in the right direction to accessing this data please?

Many thanks!

[Bushflyr]

First thing is: What NAS? If it uses a hardware RAID controller you could have problems.

[kindastuck]

First thing is: What NAS? If it uses a hardware RAID controller you could have problems.

It is an Iomega ix2. The Iomega people have suggested that accessing the data is possible (but without explaining how )

[steeldriver]

does the LiveCD system include the mdadm package? I don't think the regular install does

what does sudo fdisk -l see? does it at least identify the partition type?

is there anything like /dev/md0 or /dev/md1 in /dev?

if there is you could start by at least grabbing mdadm and then trying

$ mdadm --detail /dev/mdX

(where X is the number of the md block device) although you might need a reboot after adding the mdadm tool to get it to detect - might work if you use a LiveUSB with persistence - if not you will need to actually install a system somewhere

sorry, I'm pretty much a RAID n00b too

[kindastuck]

does the LiveCD system include the mdadm package? I don't think the regular install does

what does sudo fdisk -l see? does it at least identify the partition type?

is there anything like /dev/md0 or /dev/md1 in /dev?

if there is you could start by at least grabbing mdadm and then trying

$ mdadm --detail /dev/mdX

(where X is the number of the md block device) although you might need a reboot after adding the mdadm tool to get it to detect - might work if you use a LiveUSB with persistence - if not you will need to actually install a system somewhere

sorry, I'm pretty much a RAID n00b too

Hi Steeldriver,

Thanks for getting back to me. You have moved me forwards....

The disk utility tells me that each disk contains two "RAID Components". In each case, the first one is 1GB and the second one is 999GB. The "device" names are /dev/sda1, /dev/sda2, /dev/sdb1 and /dev/sdb2.

I ran "sudo fdisk -l /dev/sda2" and it told me:

Disk /dev/sda2: 999.2GB, 999160274432 bytes
255 heads, 63 sectors/track, 121474 cylinders, total 1951484911 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimal/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/sda2 doesn't contain a valid partition table

mdadm was not installed so I installed it. I then ran "sudo mdadm --detail /dev/sda2" and got the error message "mdadm: /dev/sda2 does not appear to be an md device".

Does that mean that this is a "sd" device (as it is sda2?). Whatever "sd" might mean .... ? (I got the same error on /dev/sda1).

[kindastuck]

I've just run "sudo fdisk -l" again and it has given a different result. I'm not sure whether that is because I have mdadm installed for for some of the other things I have been trying. Anyway, it tells me ....

Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0007ecea

Device Boot Start End Blocks Id System
/dev/sda1 1 2040254 1020127 83 Linux
/dev/sda2 2040257 1953525167 975742455+ 83 Linux

Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0005b6f1

Device Boot Start End Blocks Id System
/dev/sdb1 1 2040254 1020127 83 Linux
/dev/sdb2 2040257 1953525167 975742455+ 83 Linux

Does that help ????