How can I recover Data from a RAID 5 Array containing 3 Hard drives with 2 of the drives not working?

Hi,

    I have a situation where on a Dell Power Edge Server running Windows Server 2003 Standard x64 in a RAID 5 array ( 3 Hard Drives ) 2 of the drives failed. Is there any way to Recover the data from just one working drive. I ran each hard drive through a program called HDD Regenerator and 2 of the 3 showed the whole drive having Bad sectors. 1 drive came out with no bad sectors. are there any programs which can recreate or UnStripe the data using only one drive or am i at a total loss? Any help would be greatly appreciated.  
Computers4meAsked:
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Alan HardistyCo-OwnerCommented:
On a RAID 5 array, data is written to 2 of the drives and Parity info to the 3rd.  With one drive gone, you can calculate the data that was on the dead drive and it can be rebuilt.

With 2 drives gone, there isn't enough information to work out what data was on the other drives, so you are not going to find anything of any use I'm afraid.

Time to revert to your most recent backup.
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charlestasseCommented:
You can try sending the drives to Ontrack or Drive Savers if the data is critical. Other than that, replace with good drives and reload OS and restore from backup.
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Steven CarnahanNetwork ManagerCommented:
I'm affraid you have lost everything unless you have a good backup.  Even with RAID configurations, nothing beats a good backup.

With one drive gone it can look at the other 2 and recreate the 3rd however one drive is not capable of recreating two failed.
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DavidPresidentCommented:
Big mistake HDD regenerator corrupts data behind RAID controllers. You have now lost information for some of the recovery.  If block #2 was bad on a disk, then the controller knew that, and could use the XOR parity from the other drives.  But by regenerating them, you changed a known bad, one that has likely been bad, into data which is now "good".  The controller could have used that information, and reconstruction needs to know that as well.

Maybe the bad block was on a parity drive, so there would have been no need to reconstruct.  NEver run a regenerator on a disk behind a RAID controller since this changes how data and bad blocks are interpreted, resulting in partial data loss.

Anyway, back to problem at hand. Call in a pro.  Drives may not have really failed, you likely reached the bad block error threshold, so rebuild / reconstruction was terminated.  No way can I walk you through recovery since it would involve binary editors and specialized software to do some XOR calculations.   The off-the-shelf software for a few hundred dollars will also mess you up, as it died in a reconstruction, so you have to account for that.  The controller does background reconstruction while doing foreground I/O.

The consumer recovery software can't deal with that.  You'll end up with severe damage and large percentage of loss, even if you do binary images and work with the copies.  You need to spend $1000+ with a pro.
Turn everything off.  Every moment those disks are even powered up adds risk of further damage also.
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lscarborCommented:
True, 2 dead drives you have a real problem.
However, we've had luck with this product:
http://www.ufsexplorer.com/products.php

Recovered Buffalo RAID data thought to be unrecoverable and LSI controller RAID in a DELL 2900 -- drive issues that didn't work in the RAID controller were 'seeable' when attached to a 4 port SATA PC (Windows 7). One case was 1 dead drive in a 4 drive RAID 5, another was a 3 drive RAID that would not mount.

The product lit claims no writing and it they also do recovery. It did not write to the drives in the RAIDs we recovered and the data was copied to an external location.

Good luck.
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Computers4meAuthor Commented:
I am running Easus Data recovery Professional Paid 100.00 for it says will take 45 hours to complete but progress shows 50,000 files identified and over 450,000 files found I just hope the files I'm looking for are in the identified files. Will post as soon I get the final outcome.
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Computers4meAuthor Commented:
I ment to say I scanned the drives to identify bad sectors but I didn't do the regenerating with HDD Regen.
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DavidPresidentCommented:
Be warned, if the drives died during a rebuild, the vast majority of the files are corrupted.  Any file that is larger than the chunk size (likely 64kb) is also going to be suspect.  Best practice is also to clone the drives and run it with the cloned disks also.   If you are trying to recover a large file that is more than a few MB in size, then the odds are very much against recovery. If data is valuable, I strongly advise you stop and clone the disks with linux or perhaps easus and work with the copy also.

I wish you good luck, but be mentally prepared for corruption.
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Computers4meAuthor Commented:
Hey dlethe your right I stopped the recovery was able to get list of files recovered and everything above  65KB is corrupt The files and folders are all there but things like .jpg images come out distorted. Was looking at a company called Gillware ( www.gillware.com ) prices seem unbeatable. Any idea if this company is any good?
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CallandorCommented:
Gillware has been recommended by some of the top experts on this site - they are a reputable recovery company.
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DavidPresidentCommented:
Like I said.  I write RAID firmware, diags, and even consult for people who do recoveries.   I have not used Gillware, but it is a company that other experts  have used, and they are OK with it.   You have a perfect storm of worst case scenario.   Your HDD Generator (which I  mention again to insure it gets in database) was a big mistake .. but unless you're an internals/architect person like me, then you wouldn't have been expected to know; combined with the aborted rebuild will do in the consumer-class software you used.

All of the off-the-shelf products will give incorrect results.  I know that ontrack can deal with this.  I  have no idea if gillware has sophisticated enough people or software to deal with it.   Since you also had a drive failure then you pretty much have one shot.

Call Gillware, talk to an engineer who knows what they are doing, and tell them about an aborted rebuild and everything you do.  If he/she doesn't editorialize how much more difficult it is and that ask things like, was the system on when you were doing recoveries .. then don't use them.

Ontrack can deal with this.
(The problem is if system is online during any of this, then the blocks that were rebuilt are spread all over the drive)

But, my pessimism is still high.  without seeing it for myself and running some of my own code, I can't fully assess, but if  you are trying to get a multi GB file that was actively used and the system was online during at least part of a rebuild ... then it is likely corrupted.

Be mentally prepared for full data loss.  I'd say odds are 2:1 against getting something like a large database file, even with ontrack. Also you're probably in the $2500 - $5000 region if it is as bad as I think.
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Computers4meAuthor Commented:
Hey guys Thanks for all your help it happens that the drives were not recoverable as to the explanation of gillware. Was able to find a Tape Backup with all the critical backups on it what a relief.  
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Alan HardistyCo-OwnerCommented:
Gotta love Tape Backups :)

Glad you salvaged something.
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Computers4meAuthor Commented:
The Server was installed by another computer consulting group and they were refusing to talk to me unless they got a contract agreement signed.
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Alan HardistyCo-OwnerCommented:
Sound like Cowboys to me.  That's not the way I/we operate.
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Windows Server 2003

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