Why it is Incorrect to use Average Block Size for Storage Performance Benchmarking

Just a quick post to address something many people either get wrong or just live with due to convenience.

In summary: Please, let’s stop using average I/O sizes to characterize storage system performance. It’s wrong and doesn’t describe how the real world works. Using an average number is as bad as using small block 100% read numbers shown in vanity benchmarks. Neither is representative of real life.

Using a single I/O size for benchmarking became a practice for a vanity benchmark and to provide a level playing field to compare multiple products.

But, ultimately, even though the goal of comparing different systems is desirable, using a single I/O size is fundamentally flawed.

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7-Mode to Clustered ONTAP Transition

I normally deal with different aspects of storage (arguably far more exciting) but I thought I would write something to provide some common sense perspective on the current state of 7-Mode to cDOT adoption.

I will tackle the following topics:

  1. cDOT vs 7-Mode capabilities
  2. Claims that not enough customers are moving to cDOT
  3. 7-Mode to cDOT transition is seen by some as difficult and expensive
  4. Some argue it might make sense to look at competitors and move to those instead
  5. What programs and tools are offered by NetApp to make transition easy and quick
  6. Migrating from competitors to cDOT

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Is convenience devaluing products? Does quality suffer because of it?

Kind of a long hiatus posting (far too busy working on cool stuff) and for you looking for a deep technical post this may not be it… but here goes anyway since the content may also apply to my more usual subjects.

Recently I decided to discard my Luddite membership card and join the hordes of people using network-based services for music.

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How to decipher EMC’s new VNX pre-announcement and look behind the marketing.

It was with interest that I watched some of EMC’s announcements during EMC World. Partly due to competitor awareness, and partly due to being an irrepressible nerd, hoping for something really cool.

BTW: Thanks to Mark Kulacz for assisting with the proof points. Mark, as much as it pains me to admit so, is quite possibly an even bigger nerd than I am.

So… EMC did deliver something. A demo of the possible successor to VNX (VNX2?), unavailable as of this writing (indeed, a lot of fuss was made about it being lab only etc).

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