NVMe has been one of the hottest topics in the storage industry for a while now. Rightfully so, it is making an impact in the storage industry and moving computing forward. For storage vendors and customers alike, it is important to be ready as certain aspects of NVMe become standard. There are two key aspects of NVMe, as it promises to solve backend bottlenecks to flash devices and improve the SAN performance to servers over fabrics. In this blog, I will share my perspective on NVMe flash modules and how, here at Violin, we solve the flash device performance aspect.
I was having coffee with a friend of mine a few weeks ago and he was talking about some new phone coming out that would be 5G ready.
Now, I’m not a big “phone” guy and my friend is not in any a “Technology” guy, at least not that he realizes. As a matter of fact, he often picks at me for being a nerd. However, in taking about 5G, it made me start thinking about the impact that 5G will have on me and what I do for a living here at Violin Systems.
Back to school day.
Over at Stanford they have a speaker series that has been going on for the last few... decades, called the Stanford University Department of Electrical Engineering Computer Systems Colloquium, known to many simply as EE380. The list of past speakers is as they say, long and distinguished, and includes such industry lightweights as Joy, Lamport, Colwell, Bechtolsheim, Gray, Metcalfe, Gelsinger, Hennessy, Patterson, Brin & Page, Diffie, Mashy, Wolfram, Cerf and Kay. For a mere mortal being invited to give an EE380 talk can be an intimidating experience, which they try to make easier by telling you that there will probably be no more than 50 people in the room, thankfully they didn't mention that 10,000 people will watch the web cast online until after my talk was over. Yes, the other day Bennett and Rowett were added to the list of "past EE380 speakers."
Topics: dedup, Flash Array, groomer, MLC, solid state drive, Computer Data Storage, flash memory, flash storage, garbage collection, grooming, IOPS, jon bennett, memory array, memory arrays, PCIe, server, SLC, SSD, Systems Design, Storage Array
What about PCIe cards?
Another option is to pack as much flash as possible onto a PCIe card to sit in a high speed slot on a server. Because of their much higher interface speeds, PCIe cards have much better performance than your typical commodity SSD, but face their own unique issues. To speak with the Operating System (OS) PCIe cards require specialized software drivers. With some cards these drivers are so heavy-weight that their vendors don't even call them drivers anymore but try to convince you they are a great value added software layer. That might be true except for the fact that those cards gain their performance by stealing CPU cycles from the core that’s hosting it, the same core running the business software your trying to accelerate.
In my last post I discussed a few of the technical aspects of flash that make it a unique storage media, particularly the complexity of garbage collection. Here we take a look at flash packaging and how that impacts architectural decisions. For this post I’ll focus on the question: “Should I use commodity SSDs?” and move on to PCIe cards and Enterprise Flash Drives in subsequent posts.
It’s easy to see why HDD form factor SSDs seem attractive: they have the same look and feel as a regular disk drive, they do usually weigh less, and they fit in the same HDD connectors you have in your existing server. That's all you need to see great flash speed, right? Sure they look good in the benchmarks, and while some benchmark sites have become a lot more sophisticated in measuring SSD performance, the SSDs have also become more sophisticated at Specsmanship.
Flash is coming to the data center. Contrary to perception 18 months ago, now this seems to be accepted as ‘common knowledge.’ There is still much discussion around what that flash will look like and in what form it will be consumed. I plan to write a series of blogs describing the unique challenges involved in building large flash Memory Arrays and some of the decisions made along the road. A good place to start with is the “let’s build it myself” group of folks and the challenges they will encounter.
The very adventuresome amongst you might start with, "I'll just make my own".