Sad cojoined hard drive twins seek new lease of life.
January 8, 2010 4:58 AM   Subscribe

How can I recover data from two striped RAID drives if the enclosure is not responding? Is it possible to put them inside another enclosure and have it read the striped data correctly?

I have an 800GB Freecom Data Tank (isn't it pretty!), which contains two 400GB drives. They're configured as one single 800GB drive, which I presume means that they're striped using RAID 0. I know, it's unsafe and pointless, but I never got around to figuring out how to change it until... yes, it's too late. I am a numbskull.

Basically, the drive was hooked up via USB 2 (via a hub) to my Macbook. It's been active very strangely, disconnecting and reconnecting constantly, and only staying connected for moments at a time. I've suspected the enclosure. Now it's only even intermittently connecting, and remaining disconnected for quite some time.

Luckily, I had the critical stuff backed up elsewhere, but there's some stuff I'd really like to get at. I was hoping to get a multi-disk RAID enclosure to access the files. Is this possible, or does it have to be the specific chipset/driver/manafacturer or something?

If so, the second part of my question is what enclosure I should be looking at. I'd really like a 4-bay, as I'd like to expand to a RAID 5 for redundancy, and I really need a lot of space to store large RAW files. A Drobo sounds great, but it presumably wouldn't read anything in the RAID 0 format. I've had a look at RAID enclosures on eBuyer, Aria and Scan, and they're all rather expensive (such as this one), which is great if it works...

Ideally I'd just spend OMGsomuchmoney on a really decent solid setup, but I am on a very low income at the moment. So bonus points for answers that take that into account. For what it's worth, I've thought about buying a cheap RAID card and installing it into a PC, but I only know a couple of people who have a desktop computer(!) and they're probably not the types who'd be happy for me to be ripping them open.

All advice is gratefully received.
posted by Magnakai to Computers & Internet (5 answers total) 1 user marked this as a favorite
 
Open up the enclosure. Hopefully, it'll just be a few screws. Once you get the drives out, hook them up to a computer one way or another. Ideally, you'll have a Windows desktop to plug them into via the built in SATA or PATA controller, but failing that you can buy some reasonably priced adapters on Newegg.

Once it's mounted, try making a disk image of each drive using a live linux CD. After that, you use software to interpret the two images or the original drives. I've never tried this software, but it's free, so give it a shot. I don't know if it works with HFS+ (Mac's filesystem), though. There's probably better choices for this.

Granted, if you are in the market for a new enclosure, skip the adapters and just pick that up. Hopefully someone else in the thread has a good suggestion.
posted by mccarty.tim at 5:14 AM on January 8, 2010


I wasn't going to answer this one originally, as it had several good answers. Now it's a fairly clear field though...

Basically RAID-0 stripes the data alternately across the two drives. The stripe size and other header data changes between different hardware chips (and software implementations), so pulling the drives out and sticking them in a random RAID array is very unlikely to work; you'd basically have to get something with an identical controller to the Data Tank to get it to just work, otherwise you'll likely just end up damaging the data beyond repair. The same goes if you try and repair them with a PC RAID card.

Your best bet really is to get the drives out and plug them into a desktop PC (WITHOUT SETTING UP RAID) as standalone drives, then using a software RAID reconstructor app to rebuild the RAID 0 and extract the files to some space on a spare drive. Having the drives as HFS will add a few extra wrinkles, so you might need R-Studio or the like. (I've had good experience with diskinternals but I don't know how it'd handle HFS).

So treat the new RAID-5 array setup as a different problem to recovering your data; using one to restore the other is basically not gonna happen unless you're staggeringly lucky, I'm afraid. For a new array on its own merits, I'd go with the Drobo, they have a (deserved) excellent reputation.
posted by ArkhanJG at 12:48 PM on January 9, 2010


I had pretty much the same problem
http://ask.metafilter.com/128100/raid-0-recovery/
I got all my information back, but with 400 gigs on each drive it will take a while.

from what I read most of the different raid setups use incompatible systems, so they raid reconstruction program has to test them all out to figure it out.
posted by Iax at 1:33 PM on January 11, 2010


For my storage now i use a DNS 343. I've got four 2 TB drives in there right now in RAID 5 so the total space is about 6 TB.

Its on the low end of price and performance, but it can also run bit torrent and host the printer.
posted by Iax at 1:40 PM on January 11, 2010


Update!

After experimentation, I plugged each of the two striped drives into a USB SATA dock. I then used R-Studio to make individual images of the drives.

Aside: R-Studio lets you do everything up to the actual file recovery for free, so that you know that it's going to work before you splash the cash. Nice of them.

Then I loaded the two images into R-Studio and followed the instructions to make a striped array. But upon trying to recover the files, they all came through corrupted. The log told me that the block sizes were smaller than expected, so I tried again with a block size of 128K, and success! I recovered nearly 750GB of usable data. It took a bit over 12 hours, but worked perfectly. Only 30GB of that wasn't originally backed up, but I wanted to test it.

Thanks ArkhanJG and everyone else for the good advice.
posted by Magnakai at 3:31 AM on June 4, 2010


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