Before we begin: This is another vendor-neutral post. I realize there may be no architecture that can do everything I’m proposing, but some may come closer to what you need than others. Whether you’re a vendor or a customer, see it as stuff you should be doing or be asking for respectively…
This topic is very near and dear to me, and is one of the big reasons I came over to Nimble Storage.
I’ve always believed that storage systems should behave gracefully and predictably under pressure. Automatically. Even under complex and difficult situations.
It sounds like a simple request and it makes a whole lot of sense, but very few storage systems out there actually behave this way. This creates business challenges and increases risk and OpEx.
Recently, many vendors announced the availability of large SSDs. It’s not extremely exciting – it’s just a larger storage medium. Sure, it’s really advanced 3D NAND, it’s fast and ultra-reliable, and will allow some nicely dense configurations at a reduced $/GB. Another day in Enterprise Storage Land.
But, ultimately, that’s how drives roll – they get bigger. And in the case of SSD, the roadmaps seem extremely aggressive regarding capacities, with 100TB per device coming.
Then I realized that several vendors don’t have large SSD capacities available.
But why? Why ignore such a seemingly easy and hugely cost-effective way to increase density?
In this post I will attempt to explain why certain architectural decisions may lead to inflexible design constructs that can have long-term flexibility and scalability ramifications.
Ah, nothing to bring joy to the holidays like a bit of good old-fashioned sales craziness.
Recently we started seeing weird performance “guarantees” by some storage vendors, who seem will try anything for a sale.
Probably by people that haven’t read this.
It goes a bit like this:
<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 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).