Server virtualization is a hot topic these days (even if you haven’t heard of it before). While IT professionals have been familiar with the concept for some time, it is still relatively new and obscure for most business people.


Historically, computer servers have been dedicated to running a single operating system (OS) and typically serve a single function on a network like running a database, sending emails or hosting a website. In this traditional model, most computer servers are highly underutilized and use only a fraction of their computing power (often less than 5%). Server virtualization uses software to create a virtual machine (VM) that emulates a physical computer. This in turn allows several VMs, each with its own OS, to run simultaneously on a single physical server. Rather than paying for many underutilized computer servers, each dedicated to a specific workload, server virtualization allows those workloads to be consolidated onto a smaller number of more fully used machines.


If you have any influence on how your company or department spends its IT budget, this is what you need to know about server virtualization:

1. It Will Save You Money

I am the biggest skeptic when it comes to "save you money" schemes. I don’t believe them until I can actually count the savings in my wallet. But when our own IT department took 25 old computer servers, all of which were at the end of their useful lifespan and needed to be replaced, and consolidated them onto a single newer server, it didn’t take a PhD to do the math. That decision saved us over $50,000 in hardware alone.

2. It’s Green

By consolidating multiple underutilized servers onto a single computer server running VMs, you instantly reduce electric consumption, the physical space needed in your computer room or data center and the amount of air-conditioning needed to cool your hardware. For our 25 servers, the annual energy savings was 165,475kWh, enough to power over a dozen homes for a year. It also reduced the number of spare parts that we needed to run our operation by 64% as well as the number of physical servers that might ultimately end up in a landfill.

3. It’s Faster

But wait, it gets even better. In most cases, server virtualization will actually increase the performance of the applications running on your new VMs. By consolidating older underutilized servers onto a newer virtual server, you can take advantage of the latest advances in hardware and your applications will be able to leverage more CPU power and more memory as needed. Also, applications that use to talk to each other over a traditional network (like a Web server pulling data from a database server) can now reside on the same physical hardware and connect to each other 10 to 100 times faster. Finally, VMs can reboot 100 times faster than physical systems, resulting in less downtime during scheduled maintenance.

4. It’s More Reliable

Without getting into technical details, each VM (including the OS and all the applications) is essentially a self-contained file. This means that a VM can easily be relocated from one physical machine to another as needed, which offers several tangible benefits. First, because they are easily portable, VMs can be used in disaster recovery scenarios. Second, if a VM exceeds the computing capacity of a physical server it can easily be moved to a more powerful one. This process can even be automated so that each VM is monitored by software and instantly relocated to another server if performance suffers.

5. It’s Easier to Manage

Virtualization can help IT departments be more responsive to dynamic business needs. One of the most time-consuming and repetitive tasks in IT is the procurement of hardware and installation of operating systems. A VM with a complete server OS can be created in just five minutes on an existing server, whereas it typically takes several hours to setup a physical server (and possibly weeks to order new hardware). It is easier to perform routine maintenance on virtual servers such as hardware upgrades and security patches. And it’s easier and faster to back them up.


The three main providers of server virtualization software today are VMWare, Microsoft, and Citrix. Regardless of which vendor you prefer, the benefits of server virtualization are too great to ignore.