The technical side of a business may be afraid of virtualization because of "a lack of familiarity with the technology," Tierney said. "They see something different and don't want to deal with it."

Tierney said his company turned to virtualization to help manage server growth. But the change took work, including preparation of what he describes as an elaborate presentation for the company. One lesson learned, he said, was the need for tighter integration with IT workers involved in storage and networking. That's because VMware deployments can have an impact on those systems as well.

What often sells business managers on virtualization are the reductions in what business units pay for IT services. Virtualization can cut hardware and management costs -- savings that can be passed along, said users.

But once virtualization has been deployed, Tierney recommended that companies not draw distinctions between their physical and virtual servers.

"We wanted everybody to treat them (virtualized servers) like regular servers," said Tierney. "In the beginning, we were having some issues with people accepting virtualization and what it meant for them," he said.