IBM White Paper Sample

Virtualization has long been employed in IT systems; it’s just that we haven’t really noticed it. Take virtual memory. Although we enjoy the benefits of it on our notebook or desktop PC, virtual memory is used by an operating system (OS). Virtual I/O, the same thing. Sure, we’ve noticed virtual private networks (VPNs), but the benefits of it are mainly enjoyed by network administrators. Server virtualization has changed this, because most of us in the IT profession can relate to a server or machine, not to mention the very real economic benefits that companies are realizing from using server virtualization related to infrastructure-consolidation efforts or management techniques.

What we’re witnessing here is an exposure and utilization of virtualization at higher and higher levels in the IT infrastructure stack. Virtualization of IT resources is like an onion. At the middle are things such as virtual memory or virtual I/O. Each successive layer of the onion uses and enjoys the benefits of the virtualization layer underneath it.

This includes the notion of virtualization as applied to applications, or application virtualization. Application virtualization, at its simplest level, is just removing any dependency of an application from the underlying physical architecture. The Java™ Virtual Machine (JVM) and the Python Virtual Machine are good examples of application virtual machines. They are at a higher level, conceptually, than server virtualization, because applications run on servers (or machines). Application virtualization can extend, or complement, server virtualization.