The Xiotech ISE and Technology Fashion

We all know what fashion is. Think of Vogue Magazine, or impossibly tall, thin women walking in that special way down the elevated runway, wearing something no normal person would be able to wear, or would want to wear if they could.

But fashion extends way beyond women's clothing. Let's start with men's clothing: how many guys wear suits and ties to the office today? Then cars -- how many modern cars have those giant fins that were popular in the '60's?  The kind of popular music you like dates you at least as much as wrinkles on your skin. The more you think about it, the more you realize how pervasive fashion is.

"Technology is a counter-example," perhaps you say. "It's bits and bytes and silicon, no fashion there!" Well, that's true, except that it's people who buy the technology, and people are fashion-driven creatures. Let's face it: the cool kids who once drove sporty cars now pull out their iPhones at the slightest excuse. Waiting on line to see the Beatles; waiting on line to get the latest iPhone -- what's the difference? They're both fashion-driven fads.

"I concede that consumer technology is fashion-driven," perhaps you admit. "But hard-core computing technology, where nerds are building things for nerds; how can that possibly be driven by fashion?" I fully concur that no nerd techie would ever admit that his choices, selections and designs are driven by fashion, not even to himself. But all too often, that's exactly what's happening. The techie nerd who comes up with a design approach for solving a problem almost always prides himself on originality and foresight, without any awareness of how fashion-determined his most important decisions are. These decisions are often not made consciously; they are assumptions. "It's not worth discussing, of course we'll take approach X," the techie would respond in the unlikely event that the assumption is questioned -- by some "ignorant" (which is tech-talk for "unfashionable") person. Just to be clear: we're not talking about how nerds dress; we're talking about how nerds think.

There are examples in every field of computing technology. The Java/J2EE fad during and after the internet bubble is an obvious example, and before it client/server computing was a huge fad.

There is a clear example in storage technology today. The fashion is as clear and obvious as short skirts, and moreover is explicitly stated by its adherents: the fashion is that storage functionality should be provided as a body of software, independent of any hardware embodiment, and without regard to any particular storage hardware. Companies that previously sold storage hardware no longer have real hardware design functions -- all they do is bundle their software with hardware provided by others and sell the combination. The most popular form of this approach is to buy drive bays from an OEM and connect them to controllers consisting of off-the-shelf specially configured processors; 3Par and many others do this, for example. IBM's xiv implements a variation on this theme, using all IBM commodity server hardware. While there are still loads of dollars being spent on old-style, hardware-centric storage systems (think EMC), engineers building new storage systems are uniformly following the software-centric fashion.

In this sense, the Xiotech ISE is decided unfashionable. The ISE was invented at Seagate, in response to the CEO, Steve Luczo, wanting to create a storage product that was higher value than spinning magnetic disk drives. The idea was simple: build a fixed-format super-disk, with many Seagate drives, intelligence, etc. It would be bigger than a disk, but smaller than a SAN. It would emphasize basic storage functions (write, protect, read) and leave the "high level" storage functions to the SAN vendors.

What is interesting is that Steve Sicola and a group of other storage industry veterans ended up working side-by-side with Seagate engineers, something they never would have done at a SAN vendor. Sicola and his team knew the evolving fashions in storage quite well: ignore the details of the drives, that's "just storage." Build fancy high-level functions.

But since they were stuck with the drive engineers, they did something unusual: they actually listened to them! They learned about the amazing functions the engineers embedded in the drives that all the SAN vendors ignore. They learned how annoyed the Seagate engineers were at all the drives marked "bad" by SAN's, the vast majority of which are actually good; they learned about error codes and performance details that all the other storage engineers in the industry were studiously ignoring.

Before long, they got absorbed in what you could really do once you really knew the hardware. And, being good nerds, they invented a bunch of stuff, like how to virtualize over a fixed number of heads so that top performance was maintained even when the disks are filled up. They also invented a bunch of stuff that provides major, persisting advantages as new drives with higher capacities come out.

Since I know a fair amount about Xiotech's ISE, I want to go on and on about it. But I won't, because the point of this post is technology fashion. The purpose of bringing up the ISE is that it's a great illustration of the power of fads and fashion in technology. Any normal group of self-respecting storage nerds would have built a completely hardware-independent storage system. As such, it may have had nice features, but it would be pretty much like all the others in terms of its basic functions of reading and writing disks. But because these storage engineers were sequestered with hardware types and had a unique mission imposed from above, they did something very rare: they built a leading-edge storage system that is decidedly unfashionable. Because the engineers actually paid attention to the hardware, the ISE does things (performance, reliability, density, scalability, energy use, etc.) that no other storage system on the market today does, even though it uses the same disks available to others.

Fashion is, of course, a relative term. Fashion is one thing at diplomatic receptions, and quite another hiking in the wilderness or in a war zone. What is appropriate for one doesn't work for the other. Shoes that are appropriate for a salon can cripple you in the woods.

Well, it turns out that the modern storage fashion of ignoring the storage hardware may be acceptable in salon-type environments (where appearance and style is important but there's no heavy lifting to be done), but is as crippling as high heels in the I/O-intensive environments that are increasingly found in virtualized, cloud data centers. The ISE is like storage fashion for war zones of data, for data-intensive applications like virtualized servers, where the applications are concentrated in a small number of servers, all fighting to get their data. Most storage systems know how to hold their tea cups and conduct refined discussions and other things that matter when getting your data sometime today would be nice, thanks.

But when you've got a crowd of rowdy, tense applications all of whom are demanding their data NOW, perhaps more of a war-time style is appropriate; that's what the "unfashionable" nerds at Xiotech created in the ISE.

Comments

[Brian Corrigan]

Interesting article. This brings to mind many other examples of what happens when we allow our engineers enough time to actually RTFM; REST vs. XML-RPC for example. Disregarding the abundance of loose interpretations that exist, the general concept of REST is what you get when you _actually_read_ the HTTP RFC (and thank goodness someone did). XML-RPC is what you get when you don't understand underlying concepts likes HTTP verbs, edge caching, etc.

[David B. Black]

Excellent comment, and I love your example of REST, which goes in the face of decades of fashion orthodoxy about state-ful, method-heavy RPC's (back to client-server and before!). Dare I say CORBA? Even today, people are creating interfaces and calling them REST; god forbid they should RTFM.

Xiotech created a RESTful interface for the ISE, but even internally, they had to exercise considerable effort and diligence to assure that it actually was REST.