Tools designed to let systems administrators run multiple applications and operating systems in isolation on a single server will be introduced by key vendors in the coming weeks, paving the way for server-consolidation strategies that could save businesses big bucks. The technique, known as virtualization, has been possible in the mainframe world for years but is now becoming a more viable option for Unix and Intel platforms as IBM and Sun Microsystems prepare to roll out products.

IBM will likely add virtualization capabilities to its xSeries servers in the coming months, says Tom Bradicich, its director of server architectures. Meanwhile, Sun is building virtualization capabilities into its Solaris operating system for the first time in version 9, which is set for release next quarter. Third-party software vendors, such as VMware, are also cashing in on virtualization with new apps.

Virtualization can boost capacity utilization while reducing hardware costs. "It's a huge money saver," says Benjamin Knorr, systems engineering manager at PricewaterhouseCoopers. The consulting firm recently began using VMware's ESX Server software to create virtual machines on Intel servers from Compaq. To date, Knorr has managed to eliminate 16 physical servers by shifting workload to two servers running VMware's software, saving the firm about $60,000, he says. VMware last week released version 1.1 of its software, which features improved security and management tools.

IBM will add partitioning capabilities to its product line as a precursor to adding virtualization, beginning with a four-way system--code-named Vigil--set for debut in the next two months. To make it all happen, IBM will likely borrow virtualization technology from its z-Series mainframes, Bradicich says. Mainframes use a software layer known as a hypervisor to let a single processor run multiple operating systems.

Sun is taking a different approach. In Solaris 9, it will add soft partitioning capabilities that let users create multiple partitions within a single instance of Solaris. The partitions, which Sun calls service containers, will isolate an application and give it a share of computing resources.

"We essentially build an envelope around an application," says Andy Ingram, Sun's marketing VP for Solaris. Sun claims that its approach results in better application performance, while supporters of IBM's approach say it provides greater flexibility in that users can run multiple operating systems.