Author: Dimitris

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Interpreting $/IOPS and IOPS/RAID correctly for various RAID types

<Article updated with more accurate calculation>

There are some impressive new scores at storageperformance.org, with the usual crazy configurations of thousands of drives etc.

Regarding price/performance:

When looking at $/IOP, make sure you are comparing list price (look at the full disclosure report, that has all the details for each config).

Otherwise, you could get the wrong $/IOP since some vendors have list prices, others show heavy discounting.

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Buyer beware: is your storage vendor sizing properly for performance, or are they under-sizing technologies like Megacaching and Autotiering?

With the advent of performance-altering technologies (notice the word choice), storage sizing is just not what it used to be.

I’m writing this post because more and more I see some vendors not using scientific methods to size their solution, instead aiming to reach a price point, hoping the technology will work to achieve the requisite performance (and if it doesn’t, it’s sold anyway, either they can give some free gear to make the problem go away, or the customer can always buy more, right?)

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OS X and SSD – tunings plus performance with and without TRIM

I finally decided to spring for a SSD for my laptop since I hammer it heavily with a lot of mostly random I/O. It was money well spent.

I went for an Intel 320 model, since it includes extra capacitors for flushing the cache in the event of power failure, and has RAID-4 onboard for protection beyond sparing (there are other, faster SSDs but I need the reliability and can’t afford large-sized SLC).

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