Well here is what I ended up

pr0gr4mm3r — Tue, 17 Nov 2009 22:32:00 +0000

Well here is what I ended up doing. I have been working on this on and off since my OP. I am by no means a data recovery expert, but I like me a good challenge.

So the problem is that "Drive A" was failing, which is why the NAS failed to boot up. Here is what the partition table look like on that drive...

The partition tables are the same on each drive, except this one has that alert flag on sdc1. Clicking on that revealed all sorts of errors on the drive. It does have that same error flag on sdc4, but it doesn't even know the partition type, and when I connect "Drive B", it has the error flag on the 4th partition as well. After some reasearch, I learned that they have some proprietary filesystem, which is why it looks like a blob of data.

sdc1, sdc2, and sdc3 are system partitions that the NAS uses to boot up. They are the same on each drive, so in case one fails, the device can still boot up. When I disconnected Drive A, the device booted up, but obviously the data wasn't available. So...here is what I did recover the data (and I must say I feel like a genius).

I searched the model of the drive, and they were luckily still for sale on Tiger Direct, so I bought one. I will call this one "Drive C". I used dd to copy the system partitions from Drive B (good drive) to Drive C, and then I used dd_rescue to copy the data from Drive A (bad drive) to Drive C. So Drive C contained the system data from Drive B and the user data from Drive A. I had to use dd_rescue because there were unfortunately bad sectors in the data partition. I got all but a couple MB. All in all, not bad, but I was concerned it wasn't going to be able to mount the filesystem with the missing sectors.

So once I had my made up Drive C, I put that in place of Drive A and powered up, and...it mounted!! Seeing the list of folders was extremely satisfying. I am still copying the data off it because I have to do it a little at a time. When it hits to what was a bad sector, it locks up. Still, it looks like I am going to get most of it off the drive.

Lesson to learn: Do not use RAID 0 on a NAS unless you have a backup!

Err - on reading my own

Shaggy — Tue, 17 Nov 2009 16:28:47 +0000

Err - on reading my own answer - that isn't to say the exact SAME unit - but the same make/model unit...

Cheers,
Shaggy.

I'm by no means an expert,

Shaggy — Tue, 17 Nov 2009 16:27:13 +0000

I'm by no means an expert, but I believe you'll have a hard time getting data off the drive with anything but the same controller / software that wrote the striping/parity data across the raid array.