An Introduction to Virtualization

"New" Virtualization vs. "Old" Virtualization

The recent buzz around the word "virtualization" may give anyone the impression that it is something relatively new. Nothing is further from the truth however, since virtualization has been an integral part of server and personal computing, almost from the very beginning. To keep using the single term "virtualization" for each of its countless branches and sprouted technologies does end up being quite confusing, so we'll try to shed some light on those.

How to Define Virtualization

To define it in a general sense, we could state that virtualization encompasses any technology - either software or hardware - that adds an extra layer of isolation or extra flexibility to a standard system. Typically, while increasing the amount of steps a job takes to complete, the slowdown is made up for with increased simplicity or flexibility for the part of the system affected. To clarify, the overall system complexity increases, in turn allowing the manipulation of certain subsystems to become a lot easier. In many cases, virtualization has been implemented to make a software developer's job a lot less aggravating.

Most modern day software has become dependent on this, making use of virtual memory for vastly simplified memory management, virtual disks to allow for partitioning and RAID arrays, sometimes even using pre-installed "virtual machines" (think of Java and .net) to allow for better software portability. In a sense, the entire point of an Operating System is to allow software a foolproof use of the computer's hardware, taking control of almost every bit of communication with the actual machinery, in an attempt to reduce complexity and increase stability for the software itself.

So if this is the general gist behind virtualization (and we can tell you it has been around for almost 50 years), what is this recent surge in popularity all about?