This is a reworking of some thoughts on virtualization technology originally posted on my personal blog.  I’m breaking it into parts so that I can elaborate a little more on each aspect.

The success of any technology depends on many factors and it is helpful to reference a technology by it’s adoption in the market.  One model that has proved quite useful is the technology adoption cycle.  This model has five stages plotted along a bell curve. These stages are characterized by when the buyer adopts new technologies.  They are in order:  Innovators, Early Adopters, Early Majority, Late Majority and Laggards.

We all know that virtualization technology is nothing new; we are often reminded that it has been successfully used in mainframe computing for many years. Virtualization takes many forms; there is network virtualization, application virtualization, storage virtualization, desktop virtualization, just to name a few.  Most of the buzz today is about server virtualization, the carving up on one physical compute server to many virtual machines from the users perspective.  This type of virtualization will be the focus of this series of blog posts.

Virtualization is now also achieving major market adoption in the commodity server market as well.  I was wondering if for different classes of computing, there were different value propositions for the adoption of virtualization technology.  After reviewing a few articles and blog posts, I compiled the following list of value propositions for the market adoption of server virtualization:

  1. Server Consolidation:  Most enterprises used to deploy one business application per compute server, because in many cases, relative to the cost of the software and the business value it brought, the cost of the computer was very small.  This led to computers in corporate computer rooms multiplying like rabbits.  Studies showed that most of these computers were used at less than 20% of their capacity; the operating costs of managing, housing and powering these systems far out-weighed the capital costs of purchasing the machines; so if you owned more that a closet full of servers, there was an opportunity for serious savings.  The Green IT movement is all over this as 8 machines running at 20% consume a lot more electricity than 2 machines running at 80%.
  2. Isolation:  Software inevitably crashes, whether through internal bugs or external viruses, and an application running all by itself in a VM should not crash its host computer or other VMs running there.
  3. Protection: Since a VM appears to the host computer as a simple file (encapsulating the application, operating system, data, configurations etc.), back-up is easy.  A study by VMware identified protection as a key value proposition for small and medium businesses.  Modern file systems and storage technologies can also largely automate this process with little or no impact to operational performance.  Thus when disaster strikes (some one spills their coffee on a hard drive, or your office gets hit by a tornado), that image just needs to be re-started some where else; the business process supported by that VM could be back up and running in as little as a few seconds to a few hours, depending on the recovery requirements used to design the business continuity plan.
  4. Portability: An application is no longer tied to a specific computer.  It wasn’t that long ago when the cost of a computer was the dominating factor and software was written with hardware dependent features.  Virtualization can break this dependency (hardware dependencies can be abstracted into the virtual machine); when the computer becomes obsolete, it can be replaced with one that is more powerful or energy efficient.
  5. Heterogeneity:  Some applications run with only certain operating systems, or may only be supported against certain OS versions. Virtual machines can be instantiated for any operating system version, so on a single computer, you could run applications in Windows XP, Windows Vista, or even different distributions and different releases of Linux.
  6. Rapid Deployment:  When business needs to deploy another IT service, a VM can be copied from library and be deployed in minutes.  Gone are the days when you had to wait days or even weeks for a server to be installed and deployed into service.
  7. Security:  VMs can be standardized and security updates can be more easily managed and deployed.  Sensitive information can also be better managed.

I’d like to take these seven value propositions for the adoption of virtualization,  look at how they relate to different classes of computing and see where they fall on the technology adoption curve.  For the purposes of this series of posts I’m defining five classes of computing:  Mainframes, commodity servers, desktop computers , embedded processors and supercomputers.

We’ll wrap up this blog post considering mainframes.  Although mainframes are old, they’re certainly not dead.  They still command a portion of the market and there are still multiple vendors making and selling them.  I would characterize the buyers as late majority to laggards (although I don’t like to use that term, who wants to call their customers laggards).  Although not all seven for every buyer, I would image that purchases of mainframes have been justified by combinations of all the above value propositions.

We’ll take a look at commodity server market in the next blog post.