Understanding Flash: What is 3D NAND?

grid-cube-3d

About 18 months ago I wrote a post describing the different types of NAND flash known as SLC, MLC and TLC. However, 18 months is a lifetime in the world of technology so now I need to clarify it based on the widespread adoption of a new type of NAND flash. Let me explain…

Recap: 2D Planar NAND

Until recently, most of the flash memory used for data storage was of a form known as 2D Planar NAND (more...)

All Flash Arrays: Hybrid Means Compromise

hybrid-car-engine

Sometimes the transition between two technologies is long and complicated. It may be that the original technology is so well established that it’s entrenched in people’s minds as simply “the way things are” – inertia, you might say. It could be that there is more than one form of the new technology to choose from, with smart customers holding back to wait and see which emerges as a stronger contender for their investment. Or it could just be (more...)

Postcards from Storageland: Pure Storage Cancels Christmas

christmas-angel

Ho ho ho folks. It’s nearly Christmas Day, 2016 and it most definitely is the season to be jolly. It’s also an exciting time in the All Flash Array industry with NetApp announcing its intended acquisition of Solidfire for a reported $870 million. Merry Christmas to everyone at Solidfire!

Unfortunately those sentiments weren’t shared by Pure Storage’s VP of Product, Matt Kixmoeller, who published a blog on the subject of the acquisition which seemed a little on (more...)

Why Kaminario?

K2-mountain

This summer I made the decision to leave my previous employer and join another vendor in the All Flash Array space – a company called Kaminario. A lot of people have been in touch to ask me about this, so I thought I’d answer the question here… Why Kaminario?

To answer the question, we first need to look at where the All Flash industry finds itself today…

The Path To Flash Adoption

We all know that disk-based storage has (more...)

All Flash Arrays: SSD-based versus Ground-Up Design

design-papers

In recent articles in this series I’ve been looking at the architectural choices for building All Flash Arrays (AFAs). I surmised that there are three main approaches:

  • Hybrid Flash Arrays
  • SSD-based All Flash Arrays
  • Ground-Up All Flash Arrays (which from here on I’ll refer to as Custom Flash Module arrays or CFM arrays)

I’ve already blown metaphorical raspberries at the hybrid approach, so now it’s time to cover the other two.

SSD or CFM: The (more...)

All Flash Arrays: Where’s My Capacity? Effective, Usable and Raw Explained

capacity-effective-usable-raw

What’s the most important attribute to consider when you want to buy a new storage system? More critical than performance, more interesting than power and cooling requirements, maybe even more important than price? Whether it’s an enterprise-class All Flash Array, a new drive for your laptop or just a USB flash key, the first question on anybody’s mind is usually: how big is it?

Yet surprisingly, at least when it comes to All Flash Arrays, (more...)

Goodbye Violin… Available For Hire!

for-hire

There’s a joke among some of the longer-serving employees of Violin Memory that “Violin years” are like dog years: every normal year feels like a decade. It’s not meant in a negative way, it’s just that things change so quickly and dramatically in the flash industry that whenever we take a moment to look back it seems impossible to believe that it was only a few years ago when flash was considered a new technology and we were (more...)

All Flash Arrays: Can’t I Just Stick Some SSDs In My Disk Array?

dinosaur-velociraptor

In the previous post of this series I outlined three basic categories of All Flash Array (AFA): the hybrid AFA, the SSD-based AFA and the ground-up AFA. This post addresses the first one and is therefore aimed at answering one of the questions I hear most often: why can’t I just stick a bunch of SSDs in my existing disk array?

Data Centre Dinosaurs

Disk arrays – and in this case we are mainly talking about (more...)

Oracle’s ASM Filter Driver Revisited

filter

Almost exactly a year ago I published a post covering my first impressions of the ASM Filter Driver (ASMFD) released in Oracle 12.1.0.2, followed swiftly by a second post showing that it didn’t work with 4k native devices.

When I wrote that first post I was about to start my summer holidays, so I’m afraid to admit that I was a little sloppy and made some false assumptions toward the end – assumptions (more...)

All Flash Arrays: What Is An AFA?

All Flash Arrays - Hybrid, SSD-based or Ground-Up

For the last couple of years I’ve been writing a series of blog posts introducing the concepts of flash-memory and solid state storage to those who aren’t part of the storage industry. I’ve covered storage fundamentals, some of what I consider to be the enduring myths of storage, a section of unashamed disk-bashing and then a lengthy set of articles about NAND flash itself.

Now it’s time to talk about all flash arrays. (more...)