What is Virtualization?


In a traditional computing environment, a single computer runs a single operating system and several applications.  If you have ever viewed the CPU (central processing unit) usage on your computer running a Windows operating system, you have seen that usage often hovers around the 25% level and spikes from time to time as applications are loaded or files are read from or written to.  It is simple to see that there appears to be a lot of unused hardware capacity…and there is.

Virtualization software essentially turns one computer into many.  In other words, virtualization is the concept of running more than one “Virtual Computer” on a single physical computer.  The effectiveness of the physical system is multiplied by creating virtual versions of the computer with separate operating systems that reside on the same physical computer.  There is no additional hardware investment.

Some will harken back to the days of the “boot manager” and think they have it all figured out.  Those old boot managers allowed us to install several operating systems on a computer and to choose which one to boot from when the computer was powered up.  This allowed Windows, DOS or Unix to be installed, selectable and operable.  What makes virtualization different is its simplicity in allowing you to run multiple operating systems simultaneously.

In addition to virtual computers, virtualization has grown into two other areas of IT.  These are the areas where cloud computing has benefited most; network and storage virtualization.

The Two Types of Virtualization

Network virtualization optimizes network speed, flexibility and reliability by dividing bandwidth into independent channels assigned to individual virtual computers.  The key benefit to most businesses here is scalability.  Network virtualization is scalable on demand by effectively managing sudden, large surges in usage.

Storage virtualization is similar to network virtualization in that there is fast, reliable access to a pool of resources.  Multiple storage devices are pooled into what appears to be a single storage device.  This virtual device (the pooled resources) is then managed from a central server.  Storage virtualization accelerates data access and dynamically expands storage capacity as demand increases.

The benefits of virtualization have far-reaching consequences that most never consider.  As density of hardware has increased in the data center due to ever decreasing size of components; energy conversation has soared with the implementation of virtualization across those devices.  More virtual computers = less hardware = less power = reduced costs.  Most IT personnel in a small business environment find reduced “server sprawl” a big benefit.  There is reduced need for that additional physical server, no additional rack space and less heat without it.  The one cost that cannot be avoided…software licensing.

Additional Benefits of Virtualization

Other benefits include ease of management, reduced backup/recovery time, easily created test environments, cross-platform support and the ability to maintain legacy applications.