The open source movement is gaining momentum in the server virtualization market. Although not as popular as proprietary solutions from market leaders VMware Inc. and Microsoft, open source virtualization products are proving to be good fits for a small but growing number of enterprises.
"Enterprises have become more comfortable with using open source solutions to support their business applications," said Phil Dawson, vice president at Gartner Inc.
Open source offers businesses many potential benefits. The ability to modify the source code helps enterprises in various ways. Because they have access to the inner kernel, corporations can fine-tune their IT systems and maximize performance.
Server virtualization clients can also add new features. For instance, businesses can develop new virtualization security functions. If an attack breaks into a system, an embedded script can shut down the compromised virtual machine immediately and bring another virtual machine up in real time with no effect on users.
Citrix Inc. has been one of the main forces behind the open source server virtualization movement. In 2007, the vendor purchased XenSource Inc., an open source start up, for $500 million. The company's XenServer virtualization system was designed for Linux systems but runs on Microsoft's Windows as well.
One customer is Northern Arizona University, which has 26,000 students and 4,000 faculty and staff. The university has been using Linux and open source solutions for many years and began dabbling with open source virtualization systems in 2004.
"Many of the early virtualization products were not stable," said Dr. Tobias Kreidl, academic computing team coordinator at Northern Arizona University.
In 2008, the school, which supports 15 terabytes (TB) of data running mainly on Dell servers, wanted to deploy a virtualization system to reduce server sprawl. VMware Inc.'s solution was ruled out because of its high price. "The Citrix solution was a good fit because its Linux foundation offered us a familiar user interface," said Kreidl.
The Citrix product has garnered support from established vendors in the server virtualization market. Leading cloud service suppliers, such as Amazon and Rackspace US, rely on XenServer to run their data centers. Many service providers are constructing data centers housing tens of thousands of servers based mainly on commodity hardware running Linux. With an open source server virtualization solution, they can maximize the performance of their data center hardware.
In addition, Oracle has jumped on the Citrix bus. Oracle VM is a general purpose server virtualization product with a heavy emphasis on high-end enterprise production databases, application servers and applications. Because of the relationship, rumors have circulated that Oracle may one day buy Citrix.
Red Hat Inc. has also been involved in the open source virtualization movement. In September 2008, the vendor acquired Qumranet Inc. for $107 million. The start-up had developed the Kernel Virtual Machine (KVM) server virtualization platform and SolidICE offering, a virtual desktop infrastructure solution.
The server virtualization vendors' customer base has been growing. For instance, Colosseum Online Inc., which was established in 1994, has seen its business evolve from being a reseller to a cloud service provider. As the company's business grew, so did the need for additional space in the data center. In 2011, Colosseum Online was looking to add 20,000 square feet, an expensive proposition. In addition to the hardware purchases, the change would require significant expansion of its power and cooling systems.
Facing possibly a seven-figure investment, the business decided to examine hardware and software alternatives and ran a series of performance tests on different configurations.
"The best option from both a performance and a cost perspective was running Red Hat KVM on Cisco's UCS [Unified Computing System]," said Jean Crescenzi, chief technical officer. By adopting that architecture, Colosseum Online has been able to slow server sprawl and reduce the need for more floor space in its data center, which now supports 250 TB of information.
Open source shortcomings
Open source virtualization solutions present potential downsides as well as benefits. Cost is a complex issue. The original lure with open source was it was free; however, that typically meant that customers supported the systems themselves. Now, base solutions from folks like Citrix and Red Hat, come bundled with technical support.
"Increasingly the yearly licensing costs for open source systems are becoming comparable to those for proprietary solutions," said Dawson.
Cost savings may come from other areas, such as add-ons. If a firm builds items, like a security solution or management software itself, then its licensing costs will be less than purchasing similar commercial products.
However, the possible savings come with a caveat: Businesses must have the right staff. Many companies have Microsoft Windows-savvy tech administrators who lack the needed skills. They may be adept at traditional troubleshooting, have experience with commercial products and often do not feel comfortable digging into a product's kernel and developing new solutions. If an enterprise had a staff familiar with Linux, then it may be drawn to open source solutions. Typically, these businesses depend on software development to be successful and have employees that dabble with software in their free time.
Another challenge is changes in vendor support for the various open source initiatives. Originally, Red Hat was a XenServer supporter. However when Citrix purchased XenSource, Red Hat broke ranks and helped form the Open Virtualization Alliance (OVA), which has been a force in KVM open source development.
Vendors in the server virtualization market, such as Citrix and Red Hat, are trying to marshal the open source momentum for a more significant role in the virtualization marketplace. At the moment, it remains a significant hurdle: Gartner pegs both vendors' market share in the low single digits.
"Open source virtualization solutions are gaining more interest from customers, but currently, most feel more comfortable going with commercial solutions," said Dawson.
About the author
Paul Korzeniowski is a freelance writer who specializes in cloud computing and data center-related topics. He is based in Sudbury, Mass., and can be reached at firstname.lastname@example.org.