"You may see some performance degradation, but at least you can keep the processes running," Congdon says. "Then you can add hardware back to the pool seamlessly without having to take all those applications down while you configure the new systems."

Less obvious benefits

Aside from simple datacenter consolidation, virtualization can have a multitude of other benefits. For example, CSC uses VMware ESX Server and Solaris Containers to store and run multiple customer demonstration environments on a single physical server. "We store several versions of our ERP suites and have five or six instances of each for different client situations," CSC's Macioci says. "We simply turn them on and off when we need them and can run 15 to 20 different demo environments concurrently."

Next Financial has made advanced business continuity affordable by replicating 11 physical servers at its primary site to three physical servers with 11 virtual machines at a collocation facility. Leftover processing power is used as a primary Web server and application server farm for sales force field applications. "It would have been very expensive to have a bunch of duplicate servers sitting there doing nothing most of the time," Carlo says.

Arvato Mobile uses Virtuozzo to isolate multiple development environments on its servers, to prevent any one project from accidentally overwriting the files of the others. "We can also create a quick virtual backup so that if something goes wrong, it's easy to roll back," Arvato's Loesche says.