What Is Virtualization and What Are the Benefits?
Most agree that the number one IT investment organizations are making is virtualized
server consolidation. Virtualization is one of the hottest industry trends, for good reason.
It has the ability to increase efficiency, reduce or eliminate downtime, and deliver truly
remarkable cost savings.
Virtualization is actually not a new phenomenon - in fact the concept is just about as
old as the computer itself. IBM was virtualizing its extremely expensive mainframes in the
1960s to allow for multiple corporate users. In the 1980s IBM's central mainframe was replaced
with a distributed, client-server computer system based on inexpensive servers and desktops
that each ran specific applications. So virtualization became obsolete... for a while.
About ten years ago, when the proliferation of severs became nearly unmanageable, engineers
began to take a second look at virtualization - adapting the IBM model to the current needs
of organizations. This new generation of highly sophisticated virtual servers (referred to
as virtual machines or VMs) is credited to the developer and current market leader VMware.
Other providers include Citrix, Microsoft, IBM, and RedHat.
This time virtualization is here to stay. So the question for organizations isn't whether
to virtualize, but why not virtualize?
What Exactly is Virtualization?
The term virtualization most commonly refers to server virtualization - running multiple
operating systems on a single physical computer. While most computers only have one installed
operating system, server virtualization software allows a computer to run several operating
systems off the primary system at the same time by giving other systems access to the computer's
hardware - such as the RAM, CPU, and video cards. And, because each virtual server is isolated
from other virtualized servers, if one crashes, it doesn't affect the others.
Virtualization works by inserting a thin layer of software directly on the computer hardware
or on a host operating system. This layer contains a virtual machine monitor - a hypervisor
- that directs hardware resources. For instance, a virtualized Windows computer could run Linux
within the Windows interface. Or a Mac could run Windows within the Mac OS X interface.
In addition to server virtualization, there are four other types of virtualization:
• Network Virtualization clusters actual computing resources into a single virtual network.
• Storage Virtualization consolidates storage from multiple network storage devices into a single
virtual storage device.
• Application Virtualization separates applications from the hardware and the operating system,
allowing relocation without disrupting other systems.
• Centralized Desktop Virtualization uses a central server to remotely manage individual desktops
- this lets IT staff allocate, manage, patch, and upgrade desktops virtually.
The Very Real Cost Benefits of Virtualization
It's not hard to imagine that by reducing the quantity of servers, organizations immediately
realize a significant cost savings. VMware reports that their clients typically save 50 - 70
percent on overall IT costs. Some of the big ways virtualization saves money include:
• Increasing energy efficiency by accomplishing the same work with fewer machines. Analysts
estimate that, without virtualization, most servers use only 5 to 25 percent of their total capacity.
• Reducing labor costs by increasing the server to administrator ratio
• Creating a highly efficient computing pool that will reduce the amount of future hardware expenditures
• Allowing growing organizations to open up valuable rack space without adding more machines
Other Important Benefits of Virtualization
Applications are almost never created for a single operating system anymore and this
is where virtualization shines. It allows developers to write and test code that crosses through
an array of operating systems using a single workstation.
Virtualization creates powerful business agility. Organizations that use virtualization
to cluster, partition, and manage workloads by configuring server groups into flexible resource
pools are perfectly positioned to respond like a cat to changing marketplace demands.
Virtualization fundamentally changes the way IT managers interface with computing resources.
Instead of wasting time monitoring 100s of machines, they can turn their focus to innovating
- fully exploiting the capabilities and services the technology offers.