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Cheat Sheet: Virtualisation
Keep it unreal...

By Gemma Simpson

Published: Monday 04 June 2007

Virtualisation? So I get to put on a funky headset and walk around a simulated landscape shooting aliens?
Okay, enough with the virtual reality of yester year. We're talking about virtualisation in terms of the creation of a virtual version of something - such as server or storage device.

What's the point of that? If it's virtual it can't do anything useful in the real world, can it?
Just because you can't reach out and touch something doesn't mean it isn't real - or extremely useful to businesses.

So give me a real-life example.
You probably know a little about virtualisation if you have ever divided your computer's hard drive into different partitions - where a hard disk drive is divided to create, in effect, two separate hard drives.

This concept has been scaled up and various pieces of software have been developed so - for example - a physical server can hold a number of virtual servers, which may be running different operating systems.

But what's the point in having a virtual version instead of an actual one?
A lot of companies turn to virtualisation when they want to boost the capacity of their IT infrastructures - but in a cost and space efficient way.

One of the most common examples of how companies use virtualisation is within data centres. Virtualisation allows the number of physical servers to be reduced as the real-life racks hold virtualised images of multiple servers.

Fewer physical servers mean a smaller electricity bill from the reduced amount of hardware and the fewer cooling systems needed.

The virtualisation world is also more flexible - IT teams can shift virtual machines around the network without any manual work or the need to crawl under server room floors rearranging cables. There can be benefits from a disaster recovery point of view, too. But this is a new area of technology and some analysts are warning companies shouldn't rush in until they understand the potential security risks of virtualisation.

But in a recent CIO Jury, virtualisation was named as a key infrastructure priority for CIOs to cut costs and avoid wasting power over the next 12 months.

Where else is virtualisation getting big?
Virtualisation has dipped its finger into a variety of IT pies including blades, green computing, grid computing and service-oriented architectures. Storage virtualisation is slightly different in that it pools data from multiple devices into what appears to be a single storage device, managed from a central console.

But this is just a taster of what's to come as virtualisation starts moving more into the mainstream.

In a recent silicon.com column, Quocirca's Dennis Szubert, said: "Just like an iceberg with 90 per cent of its bulk below the surface, the massive impact virtualisation will have on IT has been largely hidden and is only now becoming widely appreciated."

So watch this (virtual) space.