So I was asked about a Western Digital MyBook World Edition II (whew, that’s a mouthful).

It stopped showing up on the network, couldn’t get anything via USB.  Wanted to know if I knew anything about data recovery.  I don’t, specifically, but I’m useful in some ways.

Looking into it, it seems these drives are dual-SATA, with some linux firmware to manage them, actually act as a NAS if you want, which is what this one was for.  However – instead of RAID1, it was set up as RAID0 – so two 500GB disks making a 1TB volume.  Makes it more difficult – if you lose one drive in that, the whole thing is dead.

I agreed to take it on – if it’s linux software RAID, after all, I’m familiar enough to play with it.

Got it, took it apart, mounted the drives.  Had to buy a power adapter and second SATA cable.  Finally left them in the half-case and dropped my desktop on its side and burned a Knoppix liveCD to work in with them.

After several tries, I think I figured it out…

mdadm -E /dev/sda4 /dev/sdb4

Will give enough information to figure out which is disk1 and disk2.  Then:

mdadm -A -R /dev/md4 /dev/sda4 /dev/sdb4 (Depending on the output of the previous command).

Then mounted that and copied stuff off.

The other three matching partitions seem to be for the system/firmware and swap, and… I don’t know.  I didn’t look into recovering the setup, just the data.  Good so far, some errors that may have been from copying files to an NTFS USB drive – all I had around.

I may look into it more in a day and try to make a full writeup… from my searching, there seems to be a dearth of information regarding the RAID0 setup of these things – which, surprisingly, isn’t really RAID0, just linear – so no striping, I gather.  Works out better in this case.

1. Miguel, February 27, 2009:

   Hello… I’ve got the same issue but i can’t mount the disks.. I’ve tried a large of methods but nothing. I used ubuntu. I will tried with knoppix. I can activate the raid but mounting nothing. Always get:

   #mdadm -Cv /dev/md4 -l0 -n2 -c64 /dev/sdb4 /dev/sdc4
   mdadm: /dev/sdb4 appears to be part of a raid array:
   level=raid1 devices=2 ctime=Thu Feb 26 18:19:49 2009
   mdadm: /dev/sdc4 appears to be part of a raid array:
   level=raid1 devices=2 ctime=Thu Feb 26 18:19:49 2009
   Continue creating array? y
   mdadm: array /dev/md4 started.
   #mount -t ext3 /dev/md4 /mnt/array/
   mount: wrong fs type, bad option, bad superblock on /dev/md4,
   missing codepage or helper program, or other error
   In some cases useful info is found in syslog – try
   dmesg | tail or so
   # mdadm –examine /dev/md4
   mdadm: No md superblock detected on /dev/md4.

   Should i try other? Thanks in advance

2. lamerfreak, April 7, 2009:

   It looks like you re-created the array, not sure what effect that would have.

   I found one of the drives in the one I was working with was intermittently dead, so the one time it stayed up, I left it.