The advent of cloud computing promises to change the face of the information technology (IT) industry forever. Just like electricity evolved from on-site generation to provision by large utilities on a pay-asyou- use basis, IT is rapidly evolving from an in-house function to one that is provided as a service from the "cloud." Although it uses some of the same premises that time-sharing did in the 1960s and 1970s, a number of key technologies are coming together now that make cloud computing a "when" not "if" question as it becomes a multi-billion dollar business. And because IT is now ubiquitous in enterprises of all sizes, the value propositions associated with cloud computing are greater than they ever could have been with time-sharing.
Virtualization, in particular server virtualization, wide area network optimization and acceleration, continuous data protection, heterogeneous asynchronous replication, and shared nothing clustering are just a few of the critical technologies that are enabling this make-over. The idea of a "killer app" has been around for awhile, and is one that can be applied to cloud computing. Early cloud-based infrastructures focused on discrete functions, such as on-demand access to almost unlimited storage capacity, as the business driver for cloud-based business models, but as virtualization technology has matured, a new "killer app" is coming to the fore: cloudbursting.