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Today, many data centers have machines running at only 10 or 15 % of total processing capacity. In other words, 85 or 90 % of the machine’s power is unused. However, a lightly loaded machine still takes up room and draws electricity. .
At its simplest level, virtualization allows you, virtually and cost-effectively, to have two or more computers, running two or more completely different environments, on one piece of hardware. For example, with virtualization, you can have both a Linux machine and a Windows machine on one system. Alternatively, you could host a Windows 95 desktop and a Windows XP desktop on one workstation.
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In slightly more technical terms, virtualization essentially decouples users and applications from the specific hardware characteristics of the systems they use to perform computational tasks.
Processor, memory, and storage resources that today must be delivered in fixed amounts determined by real hardware system configurations will be delivered with finer granularity via dynamically tuned VMs.
By applying virtualization, organizations can raise their hardware utilization rates dramatically, thereby making much more efficient use of corporate capital.
Virtualization, by offering the ability to host multiple guest systems on a single physical server, allows organizations to reclaim data center territory, thereby avoiding the expense of building out more data center space. This is an enormous benefit of virtualization, because data centers can cost in the tens of millions of dollars to construct.
A number of common uses for virtualization exist, all centered around the concept that virtualization represents an abstraction from physical resources. In fact, there are enough kinds of virtualization to make it a bit confusing to sort out how you might apply it in your organization.
The two most common types of virtualization applied in the data center are server virtualization and storage virtualization. Within each main type there are different approaches or “flavors,” each of which has its benefits and drawbacks.
For IT organizations, virtualization presents a blessing . . . and a curse. All the benefits of virtualization bring their own challenge: complexity. The ease of instantiating new virtual machines, migrating them from one server to another, accessing virtualized storage — well, it’s a long way from “one application, one server” with that one application talking to on-board storage.
Here are some Key things for you to do when you get started:
* Don’t wait for “all the kinks to be worked out.” Start small and experiment. You find out more by doing than you do by reading or even talking to others whose organization has implemented virtualization. You need to get on board today!
* Don’t skimp on training. Because virtualization is a new technology, you can’t count on people already knowing how to use it.
* Don’t imagine that virtualization is static. Not only will your business conditions dictate that you continually evaluate how well your virtualization infrastructure meets current business realities, but virtualization itself is constantly changing.
* Don’t overlook the importance of hardware. Virtualization is software that enables other software resources to take better advantage of underlying hardware. But don’t imagine that the hardware itself has no effect on virtualization. Far from it. The type and capability of the hardware you use to host your virtualization solution can dramatically impact the virtualization density you achieve, as well as the performance levels available for your virtual machines.
* Collaborate with leading virtualization providers. Most of the focus in the world of virtualization has been on the hypervisor providers: VMware, Xen, and Microsoft. Certainly a capable hypervisor is a prerequisite for a successful virtualization project.
To get more deep insight about Virtualization , you might have a look on "Virtualization for Dummies", the reference of this post :)
http://4.bp.blogspot.com/_yVzlZWcZ22...or-dummies.JPG
You can download it for free from here:
http://www.sun. com/systems/ solutions/ virtualizationfo rdummies/ index.jsp
