Green IT for Dummies®

Chapter 13. Using Virtualization

In This Chapter

• Understanding virtualization

• Building a virtual infrastructure

• Replacing physical servers with virtual servers

Once upon a time, most computers came with only one operating system on which to run applications. Then came the magic of virtualization, which uses virtual memory technology to enable a computer to run multiple operating systems or applications — all at the same time. Virtualization has become highly popular for many reasons — a main one being that it's a great way to increase the use of any computer. Companies therefore get more bang for their technology buck, always a happy result for budget-starved IT departments.

Virtualization increases utilization by consolidating applications onto fewer servers, thereby reducing the number of servers needed. This in turn reduces the data center's power consumption and cooling requirements, making virtualization one of the easiest and quickest ways to achieve a greener data center.

In this chapter, we explain how virtualization works, how it can be applied to servers and other parts of the infrastructure, and how virtualization can provide an easy start to greening the IT infrastructure.

Understanding Virtualization

Believe it or not, the idea behind virtualization dates back to the 1960s. Early mainframe computers from companies, such as IBM, had very little random access memory (RAM) in which to run programs, the series of instructions that tell the computer which tasks to perform — what ...