Look at a typical list of top IT trends, and you’re likely to find virtualization. Ask a CIO what skill set he wants from his systems administrator, and he’ll probably include virtualization. Like cloud computing, virtualization will become increasingly important and common in the future, experts say.

Interesting, because virtualization isn’t really new.  The technology has been around almost as long as mainframes. It was originally introduced in the 1960s to allow time sharing on mainframes.  It got a boost a couple decades later with VMWare that allowed developers to create test environments on their desktops.

So what is virtualization? Like cloud computing, the term has been called a “chameleon concept”.  But in general, virtualization usually refers to server virtualization, which means partitioning one physical server into several virtual servers. (You do the same sort of thing when you partition your hard drive to create several different virtual drives.) Each virtual server is able to interact independently with other devices, applications, data, and users as though it were a separate physical resource.

You can also use virtualization to combine multiple physical resources into a single virtual resource. For example, multiple network storage resources can be pooled into a single “virtual” storage device. In addition to hardware, software, memory, storage, data, and networks can all be virtualized.

Why should companies embrace virtualization? Increased IT agility and reduced costs, say many experts.  Improved use of storage arrays, reduced power consumption, and streamlined server architecture are among the many benefits.

There is a downside to virtualization, some experts warn.  The biggest problem may be security.  Joshua Corman, principal security analyst for IBM/ISS has commented that virtualization requires more discipline and security enforcement. Virtual servers may be harder to keep track of, much less protect.

Nevertheless, in a tough financial climate, companies are looking for any way to get the most from their IT infrastructure. Virtualization appears to be the simplest way to do just that.