Recent Advances Boost System Virtualization

News analysis: System virtualization has had several boosts in the past few weeks, thanks to companies such as IBM, XenSource, Virtual Iron and Intel.

System virtualization, seen as offering enterprises and smaller organizations major benefits in application availability and server capacity management, has had several boosts in the past few weeks.

While not a product, IBMs recent release of source code for its rHype Research Hypervisor project will, among other things, help the open-source Xen virtual machine monitor project.

XenSource Inc., meanwhile, announced that it will support Intel Corp.s Virtualization Technology ("Vanderpool"), which will let multiple operating systems run concurrently on Xen Hypervisor.

And last month Virtual Iron officially unveiled its VFe data center virtualization tool at LinuxWorld in Boston.

rHype, a research project at IBM, works with a variety of processors, including x86 and Power architectures, as well as with the new IBM/Sony/Toshiba "Cell," a multicore, multithreaded processor for gaming and multimedia devices.

"IBM has made the code available to its Research Hypervisor and has previously sent a message to the Xen community stating its intent to contribute some of the skills/experience behind its Secure Hypervisor [sHype] to Xen," said Jonathon Eunice, principal analyst at Illuminata Inc.

"These moves are part and parcel of the lets all get focused on supporting Xen push weve seen lately," Eunice said. "Most of the key industry players, including the leading Linux OEMs [Hewlett-Packard Co. and IBM] and the leading Linux distributors [Red Hat Inc. and Novell Inc.], have selected Xen as the open-source virtualization project theyll focus on. "This focus on Xen comes at the expense of projects that could have received similar endorsements and contributions, such as UML, VServers and coLinux. "But in general wed call that focus a good thing," he said.

"IBM is the acknowledged master of virtualization technology, going back to CP67," said Eunice. "They were working out these issues more than 35 years ago! I think bringing their IP and understanding of the performance, availability and security issues involved to bear can only help Xen mature."

Making rHype—which, he pointed out, is not production code—"is classic strategy," Eunice said. "You dont want to necessarily put your production code into open source. You want to hold some back, you have to be careful you arent giving away someone elses code ... and a lot of production code is ugly because it supports a lot of different things in a lot of practical ways. rHype is elegant, clean, newer code, with new functions that have yet to get burned into production yet."

IBM has other, related hypervisor efforts: Power Hypervisor, a commercial hypervisor for its new Power5-based servers, and sHype, a secure hypervisor research project.

"We welcome the open-source release of the rHype code base," said Ian Pratt, senior lecturer at the University of Cambridge Computer Laboratory leader and chief architect of the Xen project, and co-founder of XenSource.

Xen is an open-source virtual machine manager, a.k.a. "hypervisor" ("hypervisor" is a term being applied to many of these virtualization management tools). Xen uses "paravirtualization," which currently requires modifications to an operating system for it to be used as a guest OS.

"Xens "paravirtualization" approach admits that it needs the guest OSes help," said Eunice. "Guest OSes must be modified to call the hypervisor when they need certain low-level resources or configuration changes. This works fine for Linux and open source, but isnt going to bring Windows, NetWare or even older versions of Linux into the virtual environment."

However, earlier this week, XenSource announced it plans to incorporate technology contributions from Intel into Release 3.0 of the Xen hypervisor.

"Intels recently announced Virtualization Technology extensions to the their x86 CPU family will mean that Xen will be able to run unmodified versions of Windows on suitably equipped systems," said Pratt. "[Advanced Micro Devices Inc.] has announced they are working on similar technology, and Xen will incorporate such support in due course." The Intel Virtual Technology is expected to enable unmodified OSes to run on Xen, albeit not quite as fast as ones that have been modified.

In addition, said Pratt, "having access to this code will significantly assist the port of Xen to the Power architecture."

According to XenSource, Xen 3.0 is targeted for availability in the third quarter of this year and will include support for 64-bit processors and Symmetric Multi-Processor (SMP) guest operating systems.

Next Page: Virtualization coming of age.