The emergence of virtualization technology on the x86 and Itanium architectures and the evolution of tools such as VMware are increasing utilization levels for distributed systems, but they still fall short of the mainframe's capabilities. "To be realistic, we still have a ways to go before [distributed systems] can achieve the complete richness that the mainframe environment offers," says Barnett. But the gradual maturation of nonmainframe virtualization technology could eventually make it possible to migrate larger workloads of 1,000 MIPS and higher off the mainframe, he says.
"Virtualization is the key for bringing the mainframe and open-systems technologies together," says The 451 Group's Abbott. IBM offers its Virtualization Engine, which Rao says will increasingly be used to optimize resources across systems. "In our view, the way to deal with customers' complexity is to use a virtualization engine that will run not only on IBM platforms but also on other leading platforms," he says.
Another type of virtualization -- hardware emulation -- is also making it easier to move mainframe application environments by abstracting them from the underlying hardware. Paris-based Bull offers virtualization that enables its GCOS 8 mainframe operating system and the applications on top of it to run unchanged on its Intel-based NovaScale 9000 hardware, says Joe Alexander, Bull's director of strategy and planning. For now, however, high-end customers will have to wait for faster chip sets and performance improvements to the emulation software.
Similar technology for z/OS and OS/360 is available from Platform Solutions Inc. in Sunnyvale, Calif. The Fujitsu Ltd. spin-off sells a system that, when used with the vendor's virtual I/O subsystem, can support z/OS, as well as Linux, Unix and Windows partitions, on one x86-based system. "We bring the characteristics of the mainframe and the execution of the operating system to commodity hardware," says Michael Maulick, president and CEO of Platform Solutions. As a method of balancing workloads, IBM's approach with Virtualization Engine sounds a lot like grid computing -- an activity that's largely being driven in the open-systems arena today. "Even if IBM has an edge, it's not going to last with so much activity going on elsewhere," Abbott predicts.
The bottom line is that the hardware platform is becoming less and less relevant, says Unisys' Khanna. "It's more of what's in the operating environment and what's in the middleware," he says.