When it comes to server sprawl, the big picture is bad.

Analyst firm IDC expects the number of servers in the US to grow from 2.8 million in 2005 to 4.9 million by 2009. Data centres "are becoming more and more swollen," causing IT costs to rise quickly, IDC analyst Vernon Turner said at the IDC Virtualization Forum, which was held here last week.

The constant need for more horsepower, and the accompanying expense, are leading some IT operations to slowly turn to virtualisation technology.

The IT staff at Deluxe Laboratories, a media services subsidiary of Rank Group, manages about 400 mostly x86-based servers, and the count is growing by about 30 per cent a year, said Mark Winter, executive vice president for IT.

The company is testing virtualisation technology installed by consulting firm Savvis but Winters estimated that it will take three years to expand its use throughout the firm.

"I'm getting to the point where I'm having difficulty managing," said Winter. The server growth has pushed the company's ratio of servers to systems administrators to about 30-to-1, far higher than Winter would like. "Right now," he said, "I'm at half the number [of administrators] I need."

Desert Schools Federal Credit Union in Phoenix expects to cut costs significantly by running VMware's virtualisation software on two two-way, dual-core Opteron-based blade servers, which were installed last week, said Doug Baer, a systems engineer at the firm. Baer said the new systems are expected to handle the workload that is running on the five two-way, single-core Xeon machines they are replacing. "I can hardly imagine buying another server," said Baer, crediting the virtualisation software from EMC's VMware subsidiary. "Once you build your virtual infrastructure, you are definitely slowing down your server proliferation."

John Weeks, IT manager at Enumclaw Insurance wants to enhance his virtualised environment by adding systems running dual-core Intel chips with the vendor's Virtualization Technology (VT).

Enumclaw currently runs VMware on 40 Intel-based servers, and Weeks said he thinks that running the software on systems incorporating VT would improve virtualisation performance significantly.

VT has been included in Intel's Xeon MP chip, formerly code-named Paxville, since last year, but it had been disabled. Intel began allowing users to enable it last week.