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I need help with recovering data from an external hard drive that was in a raid.

Tags:
  • Hard Drives
  • Storage
  • NAS / RAID
  • External Hard Drive
  • Data Recovery
  • Enclosure
Last response: in Storage
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August 23, 2014 11:42:53 PM

I had a 2TB external hard drive that was made up of 2 - 1TB hard drives (I'm guessing they were in a raid) in an enclosure. It came to me in the enclosure. I didn't put them in there.

I made the mistake of plugging the incorrect power adapter into the hard drive and it stopped working. The power adapter was way too high voltage for the hard drive. I found the correct adapter and tried to access the drive with it plugged into USB and the drive wouldn't even turn on. I opened the enclosure and unplugged one drive from the board inside the enclosure and it still wouldn't turn on. I plugged that drive back in and unplugged the other one and it turned on, but still wouldn't be read by the computer.

I decided to remove the drives from the enclosure and plug them into my computer with the SATA port. I plugged the first one in and my computer wouldn't even turn on. Needless to say, I was very concerned. I unplugged it and pressed the power button and it turned on. I plugged the second drive in and the computer turned on. I went to Disk Management and could see the drive, but couldn't access it. The only thing it would let me do was format it (I didn't).

I tried to use TestDisk to recover the data. I believe it showed 4 partitions and said they couldn't be recovered. I just want to copy the files over to another hard drive and salvage what I can. I'm a graphic designer and used this drive, mostly, as a backup, but there are some files on there that aren't backed up and would love to recover my work if I can.

Any help with this situation would be very greatly appreciated.

More about : recovering data external hard drive raid

August 23, 2014 11:47:32 PM

Not sure how to go about solving your problem but if you have 2x1TB HDDs in raid thats 1TB of storage not 2TB. Just clearing that up incase you weren't sure
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a c 132 G Storage
August 24, 2014 12:21:07 AM

Depends what type of RAID. RAID 0 would definitely be 2TB.

Whether RAID 0 counts as RAID is another question, though.
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a c 327 G Storage
August 24, 2014 1:24:11 PM

Oops, I meant "the dead drive ..."
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a c 365 G Storage
August 24, 2014 1:56:44 PM

fzabkar may have pointed to a solution to your "dead drive" issue - here's hoping.

However, even if you can get that second HDD to work, recovering the data is unlikely.

To make 2 x 1TB HDD's behave as one 2 TB "drive", that external unit must have done one of two possibilities: Use them in a RAID0 array; OR use them in a JBOD array.

If it was a RAID0 array, the only really reliable way to recover that data is to connect those drives to a RAID controller that does RAID0 EXACTLY the same way as the controller in the external case. That can be tricky to find. Even then, you have to connect the two units to the controller in the right way - but there really are only two possibilities there. The problem is that, for every set of data written on the array of HDD's, only HALF of each chunk of data is on one drive, and the other half is on the other one. You MUST have BOTH HDD's working to get the data back!

Now, if you can get the second HDD working but you can't find the right controller to connect to, you MAY find software that claims to be able to read anyone's RAID0 array and recover data. I think some of those work, but I have no experience. It's a specialized form of data recovery.

In the unlikely event that the two units in the external case were in a JBOD array, not RAID0, it just MIGHT be easier to recover data. In a JBOD, data are written to the drives n the same manner as to a single HDD. It is not split up into halves on each drive. The JBOD system just sticks the second HDD's space onto the end of the first one. So just MAYBE some common data recovery software for "normal" drives could work in that case.

To find out exactly how the drives were set up in that external case, contact Tech Support of the enclosure maker. IF it was RAID0, you might ask them if you can buy a replacement enclosure with the SAME RAID0 system in it, and mount your two HDD's in that to try to make it all work again. But that's only if fzabkar's suggestion works and the second HDD can function again.

If it turns out the second HDD cannot work, and the arrangement was RAID0, there is NO hope of recovering your data. Only half of it is on the "good" unit - and that's every second chunk.
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a b G Storage
August 24, 2014 2:06:51 PM

I vote with Paperdoc: "replace external case with exact model" is the first option to consider.

We sometimes rebuild RAID0s or 1s that used generic no-name external cases (el cheapo's, in other words) with "legitimate" RAID controllers. The nice thing about El Cheapo type cases is that their controllers are built around one standard RAID Format Controller - simply because they're too cheap to have unique engineering. Sometimes, fancier Adaptec's or LSI's cards can bring those RAIDs back on-line, sometimes not.
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a c 327 G Storage
August 24, 2014 2:34:43 PM

There are software tools that can reconstruct a hardware RAID as a software RAID. In a Linux environment you could use mdadm (freeware). In a Windows environment you could use DMDE (freeware disc editor).

You would first need to locate the MBR. That would be on the first drive in a RAID 0. If the MBR is not located in sector 0, then the actual location would become the "offset" of the array.

Next you would need to determine the stripe size. In DMDE you could experiment with stripe sizes until you find a configuration that correctly reproduces the file system.

If you need a commercial tool, then RAID Reconstructor is just one of many options.
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August 24, 2014 8:01:48 PM

OK! If I am not wrong, stop using this external hard drive and try to rescue your needed data by using other drive data recovery software. There are many similar drive recovery tools that could help you somehow, except this TestDisk.
Just check this thread in this forum to see whether all the mentioned data recovery information can help you out:
http://www.tomshardware.com/forum/298659-32-free-data-r...
If these tools and thread also cannot help you out, just spend some money for professional recovery services.
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