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Proposed Disk Array With 99.999% Availablity For 4 Years, Sans Maintenance

Posted by timothy on from the with-enough-disks-all-rooms-are-full dept.

Thorfinn.au writes with this paper from four researchers (Jehan-François Pâris, Ahmed Amer, Darrell D. E. Long, and Thomas Schwarz, S. J.), with an interesting approach to long-term, fault-tolerant storage: As the prices of magnetic storage continue to decrease, the cost of replacing failed disks becomes increasingly dominated by the cost of the service call itself. We propose to eliminate these calls by building disk arrays that contain enough spare disks to operate without any human intervention during their whole lifetime. To evaluate the feasibility of this approach, we have simulated the behaviour of two-dimensional disk arrays with N parity disks and N(N – 1)/2 data disks under realistic failure and repair assumptions. Our conclusion is that having N(N + 1)/2 spare disks is more than enough to achieve a 99.999 percent probability of not losing data over four years. We observe that the same objectives cannot be reached with RAID level 6 organizations and would require RAID stripes that could tolerate triple disk failures.

5 of 258 comments (clear)

  1. Re:Naive to say the least. by alphatel · · Score: 3, Funny

    100,000 hours = 273 years. Does anyone believe that?

    Everyone except you apparently.

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  2. Re:Naive to say the least. by oodaloop · · Score: 1, Funny

    Girls suck at math.

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  3. Re:4 years??? by ArcadeMan · · Score: 4, Funny

    I am so tired of dealing with these RS/6000 systems that were made back in 1994, and these intel systems made back in 2002.

    Yeah, we get it. You like to deal with cutting-edge stuff. Now get off my lawn.

    Sent from my Commodore 64.

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  4. Re:Naive to say the least. by grylnsmn · · Score: 3, Funny

    That is one of the greatest subtle Wrath of Khan references I've seen yet.

    Spock: "Admiral, if we go by the book, like Lieutenant Saavik, hours would seem like days."

    Masterful!

  5. Re:Power Costs by Sloppy · · Score: 5, Funny

    This is how we're going bring our keepers to their knees, and eventually break out of the Matrix. We spend imaginary money on imaginary storage and then put all sorts of high-entropy stuff on it and run calculations to verify that it's really working, but they have to spend actually real resources, to emulate it.

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