Thursday 29 July 2010
The reason it is difficult to run multiple applications on a single instance of a general purpose operating system is because each application has unique needs which conflict or compete with the unique needs of other applications. Virtualization technology, such as that provided by VMware or Citrix with XenServer, breaks the bond of the application to a physical server by placing a layer of software, called a hypervisor, on the physical hardware beneath the operating system instances that support each application. The applications are “isolated” from one another inside virtual machines, and this isolation eliminates the conflicts.
Amazon embraces this virtualization model by using Xen to enable their Elastic Compute Cloud (EC2) service. I can tell you that there are lots of folks asking lots of questions about how to enable Windows applications in the “cloud.” I do not believe the answer is “Windows for EC2″ plus “Windows for GoGrid” plus “Windows for Rackspace” plus “Windows for [insert your data-center cloud name here].” If Microsoft does not find a way to turn the licensing ship and embrace JeOS, the market. irtualization enables the separation of the application from the infrastructure upon which it runs - making possible a level of business agility and dynamicism previously unthinkable. Imagine being able to run your applications on-demand in any data-center around the world that exposes the hypervisor (any hypervisor) as the runtime environment.
