• “100% successful. Well done”

    Ross Lindsay Cumbernauld

  • “A company that clearly knows exactly what it is doing, delivers exactly what it promises and does so without any fuss, just excellent service.”

    Howard Wilson Bristol

  • “Over the moon with the service, and the fact that I have all my data back is an absolute lifesaver.”

    John McNiff Pontefract

  • “You expect efficiency as standard and once you've got it, you realise that friendliness is extremely important too. Tierra does really well in both areas.”

    Daniel Batista Millares London

  • “Definitely worthwhile using your services to get back what everyone else was telling me was lost! Those photos and accounts are priceless.”

    Paul Edwards Liverpool

  • "I found Tierra to be clear, concise, straight forward, friendly, extremely professional, competent and highly knowledgeable."

    Callum Donez North East Lincolnshire

  • "Tierra salvaged my backup, with persistence that I can't have imagined."

    Gordon Dodds Cornwall

  • "Tierra stepped in quickly, efficiently and professionally restored all my lost data. Outstanding quick service."

    Jonathan Crombie Crombies of Edinburgh

  • "The level of customer service I experienced from your company was very impressive."

    Diane J Earle London

  • "This company truly understands the concept of time-critical recovery."

    Professor Ben Kneller University of Aberdeen

  • "Thank you for your professionalism, speed and quality of work."

    Anna Mavrogianni London

  • "No hesitation in recommending your company to anyone."

    Phil Codd Doncaster

  • “Thank you again for doing what the first computer repair shop I visited told me was basically not possible.”

    Kenny McLeish Carluke

  • “Tierra rocks!”

    Stephan Ringer London

What Do I Do With My Failed RAID?

by PlatterSwapper

This article will cover failed RAID 0 (data spread across multiple drives with no redundancy) and failed RAID 5 (multiple drives, but one drive can fail and RAID is still in operation). But before we get to any specifics you have to be clear in your own mind about the following:

“How important is my data?”

If the answer is “vital” then stop now and contact a data recovery company

By far the most common cause of failed RAID data proving unrecoverable even to a professional recovery company is what was done by the end user or their IT people immediately following the initial RAID failure. If you want to maximise the chances of getting your data back do nothing more with these drives.

If your data is valuable then get a quote – right now. Most data recovery companies will not charge for analysis and most operate a no recovery, no fee policy. Of course the recovery is going to cost what is probably a significant amount of money, but only if you get your data back. Imagine now that the data on your RAID has gone for good- you will have to keep going without it.

Does the failed RAID recovery quote still seem like a lot of money? Let the professionals handle it.

The only exception to this is if you are at the stage where a single drive within a RAID 5 array has failed (see below for advice). At this point as long as you are careful there should be no problem getting back to full operation without the need for professional intervention. That’s why you paid for a RAID5.

First let’s look at failed RAID 5.

One bad drive in the failed RAID:

OK, it’s a worry but you still have access to your critical data, act now and you should be fine. The one thing that you must not do is ignore it. If a second drive fails now then you are going to need professional help. Bear in mind that with most RAIDs all of the hard drives are the same model and rolled off the same assembly line together so whatever it was that caused one to fail may well be about to bring down another one as they have all spent their entire lives in an identical operating environment.

If you have an indication that one of the drives in the RAID array has failed then if it is at all practical I would strongly advise backing-up any critical data to a location outwith the RAID before you replace the failed drive. As soon as you replace the failed drive with a new one the RAID will begin to re-build itself and you’d be amazed how many times a second drive in the RAID will fail during a rebuild. Real-world deployment does not always match test-lab expectations.

Two bad drives in the failed RAID:

Most important of all is what not to do:

  1. Do not run (or allow to run) CHKDSK or any other built-in recovery utility. CHKDSK may well try to start automatically at reboot- DO NOT ALLOW IT TO RUN. CHKDSK is an excellent utility for a drive that is suffering from logical problems only, however it is data-death if one or more of your drives has physical problems (and they do, that’s almost certainly why your RAID has failed).
  2. Before you make any DIY attempt at all – clone every drive (if you don’t know how to do this without changing the drives’ contents then with the greatest respect, you are not the right person to be doing this). You can then work on the clones without making the hole that you’re down any deeper.
  3. Never, ever, ever (ever) run any recovery software that recovers to the RAID volume itself, you will be overwriting your own data.
  4. Finally never copy data that you have backed-up elsewhere back onto the RAID volume until you have recovered all of your data (again you may be overwriting critical data).

    failed RAID controller unit | Tierra Data Recovery

    Typical stand-alone RAID controller unit

Failed RAID 0:

With RAID 0 as soon as a drive fails you are in the same position as a RAID 5 owner with 2 failed drives and so the same advice applies:

  1. Do not run (or allow to run) CHKDSK or any other built-in recovery utility. CHKDSK may well try to start automatically at reboot- DO NOT ALLOW IT TO RUN. CHKDSK is an excellent utility for a drive that is suffering from logical problems only, however it is data-death if one or more of your drives has physical problems (and they do, that’s almost certainly why your RAID has failed).
  2. Before you make any DIY attempt at all – clone every drive (if you don’t know how to do this without changing the drives’ contents then with the greatest respect, you are not the right person to be doing this). You can then work on the clones without digging the hole any deeper.
  3. Never, ever, ever (ever) run any recovery software that recovers to the RAID volume itself, you will be overwriting your own data. That’s a career-defining decision right there.
  4. Finally never copy data that you have backed-up elsewhere back onto the RAID volume until you have recovered all of your data (again you may be overwriting critical data).

So if you have a failed RAID and you want your next action to be the right one, call Tierra Data Recovery on 0845 094 0027 or 0131 663 4137.

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