No Waste: Virtualization helps recapture lost resources, says Schley Stauffer Andrew Kutz of the University of Texas.

Feb 09 2007

The Virtues of Virtualization

Software simplifies server management, consolidates servers and controls data center costs.

Think of it as tuning up your data center. Benjamin N. Thompson, senior network engineer/manager at the Community College of Baltimore County (CCBC), is using virtualization software to pack the work of four servers into one. He is now getting the most out of his servers, clearing out space in his crowded data center and, most important, saving money.

“It’s a huge savings in hardware and real estate,” he says.

Server virtualization is increasingly popular in higher education, where IT departments must always do more with less. After years of kicking the tires, the nation’s IT departments in all sectors made virtualization mainstream in 2006, with 76 percent of IT organizations using or planning to deploy the technology, according to the Yankee Group, a Boston analyst firm.

The technology, first introduced in x86 servers in the late 1990s, partitions a server so it can run multiple operating systems and applications simultaneously without interference. The biggest benefit is improved server utilization, which results in server consolidation and cost savings. It also simplifies the management of servers and aids in business continuity.

Virtualization is easy to deploy and a return on investment (ROI) is almost immediate, says Yankee Group analyst Laura Didio. “Deployment is widespread and its acceptance is near universal,” she adds. Her survey of 700 IT departments found that 61 percent successfully installed server virtualization in less than a month; 26 percent saw an immediate ROI and 24 percent realized ROI within a year.

How It Works

Virtualization software from VMware, Microsoft and others allows IT departments to create multiple “virtual machines” on a server. Virtual machines, which house apps, share the same server resources, such as processing power and memory, but they operate independently. Microsoft makes its virtualization software available free. VMware offers its low-end virtualization software free, but sells a highend package that includes management software.

Because most data centers are full of servers running one application each, server utilization on average is a paltry 20 to 30 percent. Virtualization allows the University of Texas at Austin to reach 80 percent utilization.

“That’s the focus of virtualization — recapturing lost resources,” says Schley Stauffer Andrew Kutz, an operating system specialist at the University of Texas at Austin. “Otherwise, if I buy a server for $4,000 and use only 25 percent of its resources, I’ve wasted $3,000.”

When the university needed to replace antiquated servers in late 2005, Kutz persuaded his superiors to buy VMware’s high-end virtualization software for two new rack-mount servers featuring two dualcore 2.8-gigahertz processors and 12 gigabytes of memory.

He installed 20 virtual machines into each server, including a live and backup version of Symantec antivirus software, which protects the network; Windows update server software; terminal server software; and test servers for Linux software development. Kutz also used virtualization to consolidate separate Web servers.

He integrated about 10 physical servers and eliminated the need to buy three more. He plans to virtualize even more this year by buying two new servers to run VMware’s high-end Infrastructure 3 software.

Virtualization is not perfect for every application, Thompson warns. It’s memory-intensive, so using it for high-transactional software, such as large-scale databases or Exchange e-mail, is not a good idea, he says. Too many processes can compete for input-output (I/O) resources, and that impedes performance.

Thompson, who also bought VMware, averages about four virtual machines for every server with 2GB of RAM. Some applications, such as course management software, would normally require two servers to run the front-end and back-end software. With virtualization, Thompson is able to run both on the same server.

The college has 70 servers and runs virtualization software on 10 of them. “That’s four virtual machines in each server,” says Thompson. Net effect: The college has the equivalent of 100 servers.


Has it helped you cut costs as a result of server consolidation and reduced management time?

50% Yes

19% We have not attempted to calculate cost savings

19% Too soon to tell

8% Unsure

4% No

Simpler Server Management

Virtualization software by itself doesn’t make servers easier to manage. It’s the management software from vendors that simplifies server administration, says analyst Gordon Haff, of Illuminata, in Nashua, N.H.

With management software, IT staff can centrally manage virtualized environments and create rules to prioritize hardware usage. If a virtual machine has an increased workload, the software can automatically give it the extra resources it needs by rearranging virtual machines across the servers. It also simplifies hardware upgrades. “If I need to replace memory on a server, I can move the virtual machines to a backup system, put the memory in, and move the virtual machines back,” Thompson says.

Virtualization also makes it faster and easier to test and deploy new applications because IT departments no longer have to purchase a separate server for the job. They just give developers a virtual machine, which takes 10 minutes to set up, Kutz says.

As for disaster recovery, virtual machines can be copied on backup servers, says Yankee Group’s Didio. If hardware failures occur, colleges can quickly switch to backup servers to keep services running.

Learn more about server virtualization in the EdTech webinar: Capturing Real Value in a Virtual World — March 21 at 2 p.m. EDT. Register now!

How much processing power do you need?

  • How many virtual machines can you squeeze into a server? It depends on your server and applications.
  • At a minimum, school servers should have two 2.8-gigahertz processors and 2 gigabytes of RAM, advises Benjamin N. Thompson, of the Community College of Baltimore County. “The limitation is always memory, but you can get four virtual machines with 2 gigs of RAM,” he says.
  • With more memory-intensive applications, he runs three applications on servers with 4GB of RAM.
  • Schley Stauffer Andrew Kutz, of the University of Texas at Austin, believes there are no hard and fast rules for virtualizing servers. Before placing apps on virtual machines, review how much memory and processing power each uses over a two-week period, Kutz says. Then do the math.
  • Finally, adds Kutz: “Look at the statistics throughout the day. That will tell you what the memory and CPU usage is. From that, you can estimate it pretty well.”