The Importance of the Effective Capacity Ratio in Modern Storage Systems

In modern storage devices (especially All Flash Arrays), extensive data reduction techniques are commonplace and expected by customers.

This has, unavoidably, led to various marketing schemes that aim to make certain systems seem more appealing than the rest. Or at least not less appealing…

I will attempt to explain what customers should be looking for when trying to decipher capacity claims from a manufacturer.

In a nutshell – and for the ADD-afflicted – the most important number you should be looking for is the Effective Capacity Ratio, which is simply: (Effective Capacity)/(Raw Capacity). Ignore the more common but far less useful Data Reduction Ratio, which is: (Effective Capacity)/(Usable Capacity).

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Calculating the true cost of space efficient Flash solutions

In this post I will try to help you understand how to objectively calculate the cost of space-efficient storage solutions – there’s just too much misinformation out there and it’s getting irritating since certain vendors aren’t exactly honest with how they do certain calculations…

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Beware of benchmarking storage that does inline compression

In this post I will examine the effects of benchmarking highly compressible data and why that’s potentially a bad idea.

Compression is not a new storage feature. Of the large storage vendors, at a minimum NetApp, EMC and IBM can do it (depending on the array). <EDIT (thanks to Matt Davis for reminding me): Some arrays also do zero detection and will not write zeroes to disk – think of it as a specialized form of compression that ONLY works on zeroes>

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