RAID Recovery: The Data Knight Kroll Ontrack To The Rescue!

bgerber

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In the event of catastrophic hard drive failure, only professional data recovery can help. During a visit to Kroll Ontrack we gained insight into how data can even be restored from a crashed RAID array.
 

DonE

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Really enjoyed the article. Most likely because I had my laptop hardrive die on me recently. I must admit that I'm guilty of trying to see if I could fix it myself, but I've now given up completely. As a result I've decided to try use a professional service, but here in the UK they are very expensive at approx £200 for a drive. Does anybody here know of any cheaper options, or highly recommended shops?

Thanks,
E
 

p05esto

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Jun 11, 2001
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Interesting article indeed. I gave up on RAID 1 after I had a problem with the array only to find that one of the drives wasn't being written to at all...for two years I thought the array was working fine (According to bios it was) but at some point the array stopped writing to the one drive and the data was old. The other drive was failing.... I was ticked and threw RAID in the trash. Too much room for error - and user error. Nothing beats regular backups, and keeping a backup drive off-site. Too bad it's so expensive to buy 3 500GB drives....two just for back-up purposes. But still cheaper then $1k+ to recover a dead drive!
 

Luscious

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The old adage "prevention is better than cure" holds so true with hard drives. ALWAYS keep backups! You'll not only be saving your ass, but saving your time, money, job and even your marriage!

Of course, it is good to know that data recovery specialists are at hand when ALL ELSE fails.
 

ManODay

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We lost some data on a RAID Server about 7 months ago after 2 SCSI drives failed due to power fluctuation, we found and sent it out to a company in California who jerked us around for 5 days after charging us a $1,000 evaluation fee only to finally declare the data unrecoverable. We decided to get a second opinion from a local company near the New York area Called SalvageData Recovery and they got everything back for us in 24hrs.
We learned a pretty tough lesson from that experience and hope to never have to go thought it again, but Ontrack and SalvageData are the most reputable in the business.
 

joebrainer

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There is another often overlooked tool that can oftentimes allow a failed RAID set's data to be recovered: hardware logs. And this method -- if it works -- is free...

Most of the time, a perceived hard drive failure is actually the array controller flagging the drive as failed as a result of an exceeded error threshold -- not because the drive has really failed. A common effect of this can be seen when a server reports that a drive has "failed", but the drive can be resurrected by reseating.
If two drives in a RAID5 set (or even both drives in a RAID1 set) fail, check the hardware logs to see which drive failed last, then shut the system down. Pull both failed drives, then reseat JUST the most recently failed drive. Reboot the system -- if you're lucky, the most recently failed drive will come back online and stay online for long enough to secure and/or recover data.
Replace the drive that failed first with a new one, cross your fingers, and wait for the RAID set to rebuild. Once this has completed, you can then replace the other failed drive. Once the RAID set finishes rebuilding to the second drive, the RAID set's health will almost always be fully restored.
 

pkquat

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We had/are having a pretty interesting discussion here
http://forumz.tomshardware.com/hardware/Hard-Disk-RAID-Land-Minesftopic-223601-days0-orderasc-25.html

about different ways RAID arrays fail, and primarily the incompatability of controllers. So if the controller fails, its almost as bad as if all the hard drives crashed.

What I am wondering is what a recovery place does to recover data from a RAID 1 array where the controller fails? I had been under the assumption that with a RAID 1 array, if the controller (or MoBo) crashed, (but didn't splatter the data all over the drive(s), that a person could at least put one of the drives in another computer to at least recover the data. I learned this is incorrect. I mentioned in the thread above how nice it would be if the RAID controller supplier also included some software to at least be able to recover data off one of the drives if the controller fails.
 

Luscious

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RAID 5 and RAID 1 will protect data from a hard drive crash, we all know, but it won't help at all if, as you say, the controller goes dead.

A redundant level of protection using another backup medium is even better when one day you get into a situation where you know that your hard drives are good, but either the controller is freaking out or your data has been messed up.

That's exactly why I always have a tape drive installed in every RAID system. It not only gives me protection against controller failure, but will also protect me from any accidental file deletion and lets me keep a copy of all my files in a safe location offline.

You can never be too careful with backups when you resort to using RAID.
 

rockgeek

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I'm still very very confused why people go to OnTrack. They charge for diagnosis so even if they are too lazy not to recover the drive, they'll charge you anyway. Also, after they calculated whether your work is going to be profitable enough, they charge you again, and a hell lot more.

Their success rate is beyond a joke. Granted, they probably do more recoveries than anyone else isn't that why the diagnosis was brought in?

Firms like http://www.retrodata.co.uk and http://www.r-tt.com/ have such a better reputation, at much reduced prices, with improved customer service and at higher success rates.
 

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