Category: Rants

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The Loss of Important Knowledge and Acumen Through Perceived Commoditization

I posit that we now have a whole new class of consumer that is completely oblivious to certain hitherto fundamental concepts – and this can lead to poor business decisions and overall sub-optimal execution and results.

I got the idea after a discussion with an ex colleague (that’s now working for a cloud vendor) where he proudly proclaimed that infrastructure is unimportant and uninteresting.

I’ll start generically and shift to IT. The generic aspect of this problem is very interesting, since it’s lowering quality in all sorts of fields.

And never forget: Just because something is widely and easily available doesn’t mean it’s better. It simply means that more people have access to it.

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Media is Not Created Equal and NVMe is Just a Protocol

In this era of over-marketing and misinformation, it can be refreshing to clarify things for customers.

Allow me to be refreshing regarding NVMe 🙂

NVMe is simply a protocol. Just like SCSI is a protocol. NVMe is most assuredly not a media type. Yet, storage vendors keep talking about “NVMe drives” and customers often think those devices are equal as long as “NVMe” is mentioned.

Alas, that’s not how things work…

Strictly speaking, there’s no such thing as an NVMe drive. Or, at the very least, calling something an “NVMe drive” isn’t enough to describe what that media is, and it’s especially not enough to describe how fast it may be.

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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).

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

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So now it is OK to sell systems using “Raw IOPS”???

As the self-proclaimed storage vigilante, I will keep bringing these idiocies up as I come across them.

So, the latest “thing” now is selling systems using “Raw IOPS” numbers.

Simply put, some vendors are selling based on the aggregate IOPS the system will do based on per-disk statistics and nothing else.

They are not providing realistic performance estimates for the proposed workload, with the appropriate RAID type and I/O sizes and hot vs cold data and what the storage controller overhead will be to do everything. That’s probably too much work.

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An explanation of IOPS and latency

<I understand this extremely long post is redundant for seasoned storage performance pros – however, these subjects come up so frequently, that I felt compelled to write something. Plus, even the seasoned pros don’t seem to get it sometimes… 🙂 >

IOPS: Possibly the most common measure of storage system performance.

IOPS means Input/Output (operations) Per Second. Seems straightforward. A measure of work vs time (not the same as MB/s, which is actually easier to understand – simply, MegaBytes per Second).

How many of you have seen storage vendors extolling the virtues of their storage by using large IOPS numbers to illustrate a performance advantage?

How many of you decide on storage purchases and base your decisions on those numbers?

However: how many times has a vendor actually specified what they mean when they utter “IOPS”? 🙂

For the impatient, I’ll say this: IOPS numbers by themselves are meaningless and should be treated as such. Without additional metrics such as RAID type, randomness, latency, read vs write % and I/O size (to name a few), an IOPS number is useless.

And now, let’s elaborate… (and, as a refresher regarding the perils of ignoring such things when it comes to sizing, you can always go back here).

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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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Questions to ask EMC regarding their new VNX systems…

It’s that time of the year again. The usual websites are busy with news of the upcoming EMC midrange refresh called VNX. And records being broken.

(NEWSFLASH: Watching the webcast now, the record they kept saying they would break ended up being some guy jumping over a bunch of EMC arrays with a motorcycle – and here I was hoping to see some kind of performance record…)

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Et tu, Brute? EMC offering capacity guarantees? The sky is falling! Will Chuck resign?

It came to my attention that EMC is offering a 20% efficiency guarantee vs the competition (they seem to be focusing on NetApp as usual but that’s besides the point in this post). See here.

Now, I won’t go ahead and attack their guarantee. Good luck with that, more power to you etc etc. They need all the competitive edge they can get.

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