Until recently the primary motivator for deploying server virtualization was consolidation. Server virtualization gave organizations a way of controlling their sprawling physical server environments by letting them run more than one application and one operating system on a single physical server.

It was an IT manager's dream and, as it turned out, a CIO's too. Server virtualization has had a ripple-effect of positive change throughout organizations, helping them to reduce IT capital and operational costs, improve server utilization rates, simplify server management and maintenance, and even protect their resources from disasters or system outages better.

While these core benefits of server virtualization are still important to organizations today, the ability to reduce IT power and cooling requirements is playing a significant, and growing, role in purchasing decisions. Rising electricity costs, limited power resources, and the world's commitment to "all things green" have combined to raise the visibility of server virtualization as a core power-reducing IT technology.

In fact, according to a recent survey from the Enterprise Strategy Group (ESG), 63% of organizations with fewer than 100 employees said that being able to reduce power and cooling requirements was a key motivator for their implementing server virtualization. Fifty-eight percent of large organizations - those with 100 to 999 employees - also cited the technology's energy-reducing capability as a key driver of adoption.

In number terms, industry experts estimate the kilowatt-hour savings of running an application on a virtual versus physical machine to be on the order of 7,000 kilowatt-hours, or about $700 a year per server. From an environmental perspective, getting rid of a single physical server can reduce the carbon footprint by four tons a year. This has the same overall impact of planting 20 new trees or removing the emissions from two mid-sized automobiles per eliminated physical server.

However, for some organizations - in particular large ones or those located in population-dense regions of the world such as New York City or California - the ability to reduce power and cooling requirements can have dire business consequences. For some, it can mean the difference between keeping applications and associated servers running, or not, because there is no more electricity available to them to keep infrastructure powered and cooled.

Again, by virtualizing the server environment, organizations can reduce the number of physical servers they need to run the same number of applications. Fewer physical servers mean less IT infrastructure to power and cool. It's that simple.

Organizations that combine server virtualization with complementary IT technologies, such as blade technology, can see even more dramatic power- (and space-) reduction benefits.

The following use cases are two examples of how server virtualization technology can be used in combination with blade technology to reduce power and cooling requirements.

Regional Healthcare Provider
Situation: Like many health care organizations, this Massachusetts-based health care provider has undergone a major transformation in recent years by digitizing and storing stockpiles of patient information. Doing so has had enormous benefits from a data retrieval standpoint but has taxed the facility's IT infrastructure, requiring more servers, more floor space, and more electricity for power and cooling. IT costs at this hospital, and others like it, escalated as a result.

Solution: The hospital replaced its existing physical server environment (a three-tier, 8 foot x 8 foot tower with 30 rack-mounted servers) with a single virtualized server environment consisting of a single 2 foot x 8 foot blade system. As a direct result, the hospital has been able to reduce its data center footprint significantly as well as associated power and cooling requirements. The hospital has cut its IT budget by 10% during each of the last two years (since the deployment) and its computing capacity by 20% each year.

State University Computer Science Department
Situation: Power and cooling has been a big concern for this state university in New England, as it is for most institutions of higher education. It has a very visible green computing initiative, which provides funding for IT infrastructure improvements such as server virtualization and blades. The university's computer science department was looking to update its aging IT infrastructure. Much of its equipment was either nearing end of life, out of warranty, or extremely underutilized. It wanted a solution that not only met its computing needs but also supported its green initiative.

Solution: The computer science department moved much of its existing IT infrastructure onto blades and implemented server virtualization, consolidating 16 servers onto four blades. The new infrastructure has significantly lower power requirements and generates significantly less heat. Cooling requirements have been reduced from 20 to eight fans.

Summary
Server virtualization, on any scale, can enable organizations to lower power and cooling consumption by reducing the amount of physical servers they need to operate, power, and cool. In today's world, this is huge - not just from a dollar standpoint but from an environmental perspective.