Archive for October, 2009

Appliances – Good, bad or virtual ?

So, in another prime example of “Why do Analysts blogs make it so hard to have a conversation?” , Gordon Haff of Illuminata today tweeted a link to a new blog post of his on appliances. No comments allowed, no trackbacks provided.

He takes Chuck Hollis (EMC) post and opines various positions on it. It’s not clear what the notion of “big appliance” is as Chuck uses it. Personally, I think he’s talking about solutions. Yes, I know it’s a fine line, but a large all purpose data mining solution with its’own storage, own server, own console, etc. is no more an appliance than a kitchen is. The kitchen will contain appliances but it is not one itself. If thats not what Chuck is describing, then his post has some confusion, very few organizations will have a large number of these “solutions”.

On the generally accepted view of appliances, I think both Gordon and Chuck are being a little naive when they think that all compute appliances can be made virtual and run on shared resource machines.

While at IBM I spent a lot of time, and learned some valuable lessons about appliances. I was looking at the potential for the first generation of IBM designed WebSphere DataPower appliances. At first, it seemd to me even 3-years ago that turning them into a virtual appliance would be a good idea. However, I’d made the same mistake that Hollis and Haff make. They assume that the type of processing done in an appliance can be transparently replaced by the onward march of Moores Law on Intel and IBM Power processors.

The same can be said for most appliances I’ve looked at. They have unique hardware design, which often includes numerous specialized processing functions, such as encryption, key management and even environmental monitoring. Appliances though real value add is that they are designed with a very specific market opportunity in mind. That design will require complex workload analysis, and reviewing the balance between general purpose compute, graphics, security, I/O and much more, and producing a balanced design and most importantly, a complete user experience to support it. Thats often the key.

Some appliances offer the sort of hardware based security and tamper protection that can never be replaced by general purpose machines.

Yes Hollis and Haff make a fair point that these appliances need separate management, the real point is that many of these appliances need NO management at all. You set them up, then run them. Because the workload is tested and integrated the software rarely, if ever fails. Since the hardware isn’t generally extensible, aka as Chuck would have it, you are locked into what you buy, updating drivers and introducing incompatibility isn’t an issue as it is with most general purpose servers.

As for trading one headache for another, while it’s a valid point, my experience so far with live migration and pools of virtual servers, network switches, SAN setup etc. is that you are once again trading one headache for another. While in a limited fashion it’s fairly straight forward to do live migration of a virtual workload from one system to another. Doing it at scale, which is what is required if you’ve reached the “headache”point that Chuck is positing, is far from simple.

Chuck closes his blog entry with:

Will we see a best-of-both-worlds approach in the future?

Well I’d say that was more than likely, in fact it’s happening and has been for a while. The beauty of an appliance is that the end user is not exposed to the internal workings. They don’t have to worry about most configuration options and setup, management is often minimised or eliminated, and many appliances today offer “phone home” like features for upgrade and maintenance. I know, we build many of them here at Dell for our customers, including EMC, Google etc.

One direction that we are likely to see, is that in the same current form factor of an appliance, it will become a fault tolerant appliance by replicating key parts of the h/w, virtualizing the appliance and running multiple copies of the appliance workload within a single physical appliance, all once again delivering that workload and deployment specific features and functions. This in turn reduces the number of physical appliance a customer will need. So the best of both worlds, although I suspect that not what Chuck was hinting at.

While there is definitely a market for virtual software stacks, complete application and OS instances, presuming that you can move all h/w appliances to this model, is missing the point.

Let’s not forget, SANs are often just another form of appliance, as are TOR/EOR network switches, and things like the Cisco Nexus. Haff says that appliances have been around since the late 1990’s, well at least as far as I can recall, in the category of “big appliances”, the IBM Parallel Query Server which ran a customized mainframe DB2 workload, and attached to an IBM S/390 Enterprise Server was around in the early 1990’s.

Before that many devices were in fact sold as appliances, they were just not called that, but by todays definition, thats exactly what they were. My all time favorite was the IBM 3704, part of the IBM 3705 communications controller family. The 3704 was all about integrated function and a unique user experience, with at the time(1976) an almost space age touch panel user interface.


About & Contact

I'm Mark Cathcart, formally a Senior Distinguished Engineer, in Dells Software Group; before that Director of Systems Engineering in the Enterprise Solutions Group at Dell. Prior to that, I was IBM Distinguished Engineer and member of the IBM Academy of Technology. I'm an information technology optimist.


I was a member of the Linux Foundation Core Infrastructure Initiative Steering committee. Read more about it here.

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