How to retrieve data from an external hard drive, when it was the enclosure that went bad?
November 15, 2010 2:58 PM   Subscribe

How to rescue data from two SATA drives housed in an external hard drive, where the drives seem to be OK - it was the enclosure that died?

My boss had a 1T Phantom external hard drive where he stored his movies and music. After working perfectly fine since early 2007, suddenly the drive wouldn't fire up at all - the light came on, but no power went to the hard drives or to the fan. The drive is way out of warranty, so we opened up the case, unplugged the two WD 500GB SATA drives , and tried getting at least the fan to start (it always started right away before), but no dice. Looks to me like the hard drive enclosure itself is the problem here.

If it was just one hard drive, I would just plug it in as an internal drive on my computer and copy the info to a new external hard drive. But I have no idea how to do this given that it's two drives. Would buying a new dual-bay external hard drive enclosure allow me to plug them in and extract the data? If so, would any enclosure do, or should I look out for specific features? Would I need something like R-Studio to get my computer to recognize that the drives already hold data? Any other recommendations of software I would need?

I can't figure out the model of the Phantom drive, and he doesn't know either, so I can't look up how it was set up/which controller, etc. I believe he has some of the content of the drive backed up, but he really doesn't want to lose the data if at all possible. I have access to a Mac laptop and several Windows PC:s, should the need arise to use them.

Your thoughts would be much welcome.
posted by gemmy to Computers & Internet (10 answers total) 2 users marked this as a favorite
Take the enclosures apart, and then use a hard drive dock, like these products (Newegg link)
posted by jnrussell at 3:14 PM on November 15, 2010

gemmy, could we get the exact model of the drive? There are several varieties of Fantom brand 1TB external drives.

The big question is if the two 500GB hard drives were set up as two separate drives, or if they were in some sort of RAID configuration. My best guess is that it is in some form of RAID 0. Likely, the drives need to be put into the same or a very similar enclosure to ensure you can pull the data off of them.

You may be best off calling their tech support to get the correct answer: 800-322-8581.
posted by Mister Fabulous at 3:18 PM on November 15, 2010 [1 favorite]

Of course, that doesn't answer the question of whether the dock will recognize both disks as a RAID array, which I assume they are. Not sure how to fix that aspect of the problem, but the docks seem like a good start since they aren't enclosures, many of them can fit two drives at once, and you can re-use them for other future problems.
posted by jnrussell at 3:18 PM on November 15, 2010

My goof, missed the part about not being able to discern model.
posted by Mister Fabulous at 3:26 PM on November 15, 2010

I'm curious, when he used the drives did it read as a single 1TB drive? If thats the case, ignore everything that I say, as I have no experience with that. (and am skeptical that something like that would even work...)

Any enclosure (with the right specs) will work. You'll find it cheaper to get two enclosures than a dual bay or enclosure. Lots of enclosures will stack nicely, though it depends on what this guys preferences are.

I wouldn't bother getting a new drive to copy the information on to. Just get a new enclosure or drive bay. I'd get a cheap one to start, and test each drive to confirm your suspicion that the drives are OK.

Newegg Enclosures Category has every possible option you'd need.

Also, that drive is getting to be a bit old at 4 years. You'll want to add some backup and disk check to your/his maintenance rotation. 1TB of info to loose all at once would be tragic. (which is part of the appeal of these split "1TB" 2x500GB drives)
posted by fontophilic at 3:28 PM on November 15, 2010

It sounds like the external drive was a RAID unit. A lot of external drive enclosures use the same chipset (Oxford is one of the major manufacturers) so it's possible that you can find a similar enclosure that uses the same chipset and just plug in the two drives.

You might want to poke around in the forums at TomsHardware or Anandtech or maybe even SuperUser to see if those resources turn up anything.
posted by kenliu at 3:56 PM on November 15, 2010

Response by poster: Thanks to everyone so far. Yea, when he used the external hard drive it did read as one 1TB drive. That's why I'm a bit worried, tbh, because I have no experience with how that might be set up.

I've been telling him to run maintenance on it and to back it up elsewhere too for a while, and he was in the process of getting a larger drive to do a backup onto. Bad timing...
posted by gemmy at 3:59 PM on November 15, 2010

Best answer: First thing is to get yourself a 2TB drive and save a complete block-for-block image of each of the 500GB drives onto it. That gives you the freedom to try out all kinds of data recovery options without risking data loss.

There are two ways I know of to make a pair of 500GB drives look like a single 1TB drive. The controller can simply direct all requests involving block numbers in the low half of the 1TB to one of the drives, and requests for block numbers in the high half to the other (with a suitable offset subtracted); effectively, the second drive is just appended to the first. This is JBOD (Just a Bunch Of Disks) mode.

The other way is RAID-0, where the blocks are grouped into "stripes" that are dealt out across the drives like playing cards. For example, the first 16KiB of the logical 1TB drive might go on 500GB drive 0, the next 16KiB on drive 1, the next 16KiB on drive 0, the next on drive 1 and so on. If this is what the controller in the old enclosure did, it may well also have stuck a few metadata blocks onto each drive describing the stripe layout, the metadata possibly being in some proprietary format.

Metadata like that is commonly kept at the end of each physical drive, and you might be able to ignore it completely while still rearranging drive accesses by stripe using Linux software RAID. There's a fair old learning curve if you haven't played these games before, but if your boss is willing to pay you to learn to play them, go for it. Provided you always keep a set of pristine image backups, you won't ever do irretrievable damage.
posted by flabdablet at 6:59 PM on November 15, 2010 [1 favorite]

Response by poster: Thanks again to everyone who answered. I tried a few things, using flabdablet's advice on block by block backups to ensure that I didn't mess things up irretrievably. From what I can tell, I was able to salvage the majority of the files on the two drives, about 605GB. What I ended up doing was this:
  • I got a dual hard drive docking station from Newegg. (Just make sure to choose not to format the inserted drives when you first plug it in to the computer.)
  • With the docking station, I was able to use ddrescue, as recommended by flabdablet, to make backup copies of the two drives onto a 2TB external hard drive. That way, I was sure not to accidentally overwrite any data. (Turns out that the software I ended up using also had a block by block imaging option, but I had already made backups by the time I found out.)
  • Then I ended up purchasing and using a software recovery solution called R-Studio to actually extract the files. I liked this program because the demo version allowed me to create any RAID setup and virtual volumes I wanted in an easy drag-drop interface, and I was able to see how many files and how many GBs of files would be recoverable depending on the setup options I chose. So I was able to actually see that the software would work for me, before I made a purchase. I just had to buy the program before I could actually begin to recover any files larger than 64KB.
  • I ended up using the simplest "virtual volume" option, rather than the more complex virtual RAID option, because I could see that doing so would net me the largest number of files, and that the files would be recoverable with the original folder structure intact.
It took a lot of reading and figuring things out, but I learned a lot about RAID setups and command line options during this exercise, and my boss is happy with what I was able to do. Thanks to everyone for helping me be a star!
posted by gemmy at 8:42 AM on January 27, 2011

Result! Well done you.
posted by flabdablet at 5:05 PM on January 27, 2011

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