By investing in virtualization software, a small Maine liberal arts college eliminated about one-third of its physical servers and sidestepped about US$356,000 for new systems, even as it added enterprise applications. The server consolidation at Bowdoin College, in Brunswick, Maine, grew out of a limited test of ESX Server, virtualization software from EMC subsidiary VMware. Initially, the IT group wanted to use the software to create virtual servers that could be dedicated to testing new or upgraded applications before they were deployed in full production mode.
Two years ago the IT group launched a trial deployment. The ESX software acts in effect as the operating system on the "bare metal" of the blade servers: It's in charge of the physical computing resources -- CPU cycles, memory, disk space, etc. -- and allocates these in response to the demands of the applications. The applications run in what are called virtual machines, self-contained software bubbles with a claim to the underlying CPU resources on the blade.
"It's kind of like the old mainframe model, where each user's job got a slice of the CPU's time," says Tim Antonowicz, Bowdoin's systems administrator. "VMware ESX Server does the same thing with the virtual machines: It drops a VM onto the blade server hardware, runs the cycles it needs and then [drops on] the next one, cycling through all of them." The virtual machines are exploiting what previously would have been idle CPU cycles. As Bowdoin discovered, applications now can run on fewer physical servers. New virtual machines can be created within minutes or allocated additional virtual memory or disk space with a few mouse clicks. A new application can be safely tested, or an old one modified, on one or more dedicated virtual machines and then deployed quickly to a production virtual machine.
These virtualization virtues became apparent in late 2004, as Bowdoin's infrastructure was stretched to the limit. The small data center was jammed, with five racks of servers. Many of them sat idle for most of the day: The public safety department had a dedicated server to handle traffic tickets, which was used at most a few times each day, Antonowicz says. At the same time, Mitchell Davis, the college's first CIO, was planning to rewire the entire campus with fiber for Gigabit Ethernet and to deploy major application upgrades to serve about 1,600 students, 179 faculty and 600 staff.
The new financial system, Blackbaud's Financial Edge, alone would need 10 to 16 new servers to support the planned configuration.
"The IT staff came to me and said, 'We think we can deploy everything on VMware,'" Davis recalls. Bowdoin selected the HP BL20 blade servers, buying 15 of them. Eight blades run ESX Server instances, with a ninth instance running on a Dell server. The IT staff was able to cut the number of physical servers from 72 to 46 (including the 15 HP blades).
Today, Davis says, 58 percent of Bowdoin's applications run on virtualized servers. The Blackbaud application uses three ESX blades to create a SQL Server database cluster, with 13 virtual machines to run such services as a Microsoft IIS cluster for Web access, a Microsoft Terminal Services cluster for access by Mac users, an application management server, and multiple testing and staging servers.
The 15 HP blade servers came to US$93,000. VMware's ESX pricing for the education market is US$3,000 per server, which can each support multiple virtual machines, for a current total of US$27,000.
Antonowicz says that to support the new applications deployed, 57 additional physical servers would have been needed. But as a result of using virtualized servers, Bowdoin bought none apart from the blades. Antonowicz estimates the 57 boxes would have cost US$356,250.
Monitoring and managing the new server environment has been dramatically streamlined. "I can add memory, increase a hard drive, add a second CPU or network card, all from a secure VMware Web interface," Antonowicz says. "And by having a way to roll back a server rapidly to a previous disk image or a backup, I can respond to disasters quicker."