THE PHRASE virtual has been taken over by the computing establishment, with the term virtual reality now part of everyday vocabulary.
However, there’s a new type of virtual buzzword that’s sweeping the technology arena spurred on by technology vendors such as Intel and AMD and the massive power that their processors now have and that is Virtualisation.
Virtualisation refers to running one operating system inside another. So if you had a computer running Windows XP and you wanted to mess around with Linux (or test an application running under Linux) you could fire up some virtualisation software and install and run a version of Linux inside Windows.
However, virtualisation will go a step further if new developments are anything to go by. Instead of having to use a host operating system, such as Windows XP, and a guest operating system such as Linux, virtualised systems will have a special type of software, known as a hypervisor.
The hypervisor is like a very light operating system, with only one real function, to allow many other operating systems to access the physical computer at any time.
Imagine it as the nursery school teacher in charge of a limited set of toys (things like the ability to access the computer’s CPU, memory or reading and writing from the hard drive) and it has any number of petulant children all wanting to play with the toys at the same time. The hypervisor ensures that not only do all the children get to play with the toys, it fools each one of them into believing that he/she is the only child in the school.
This is because each operating system wants exclusive use of the computer and doesn’t want to share it with any other.
However, in the data centres that power the world’s corporates, governments and the Internet the application is very different.
With virtualisation the system administrators create a virtual pool of all the computing power in the company and allocate it depending on what application needs the power at any given time.
Although there are hundreds of computers physically, it’s possible to fool the operating system into believing that there’s only one very powerful computer. This makes managing these computers much easier.