In fact, if CIOs haven't virtualized at least a part of their server populations by now, they are woefully behind the curve. When Arch Coal CIO Michael Abbene began investigating virtualization products in 2006, "I tried to get a sense of who else was doing it", he recalls. "It turned out to be everybody."

According to IDC, 75 percent of companies with 1000 or more employees are employing virtualization today. And more than half of the respondents to the Aberdeen Group survey on virtualization were using it in their production environments (meaning, everyday user applications), "a clear sign that end users trust that the technology is mature enough for mission-critical systems".

Data centre consolidation is a critical first step toward unlocking virtualization's potential because it demonstrates to the business that IT can run more cost-effectively — slashing server costs plus tackling expensive power, cooling and real estate expenses. IDC says enterprises spend 50 cents to power and cool servers for every one dollar in server spending today (that number will increase to 70 cents by 2010), and new data centre costs run $US1000 per square foot. Abbene says that consolidation has enabled him to defer a major data centre upgrade that would have cost him around $US400,000.

According to Abbene, as long as you don't overburden physical servers with too many VMs, you won't notice any degradation in application availability. And as long as applications are running just fine, "they don't need to know what box [their applications] are running on". Despite serious growth at the $US2.5 billion company over the past three years, Abbene reduced his overall budget by 10 percent to 15 percent a year, largely due to his server virtualization efforts.

In fact, Abbene says that at his company, many businesspeople have become enamoured of the virtualization concept. "They'll say: 'I want a virtualized server'," he says.