Linux kernel to adopt server virtualization

Computerworld - BURLINGAME, CALIF. -- Support for open-source software that provides server virtualization capabilities is due to be added to a future version of the Linux kernel, sources familiar with the technology said last week.

But although Andrew Morton, the maintainer of the Linux 2.6 kernel, confirmed at the OSDL Enterprise Linux Summit here that support for the Xen open-source virtualization software is "going to happen," he wasn't clear about the time frame. Morton said it won't be included in the 2.6.11 version that's due late this month. But, he added, Xen support might be built into one of the two subsequent releases of the kernel that are expected later in the year.

Much will depend on the stability of the code that is submitted to Morton, said a spokesman for Beaverton, Ore.-based Open Source Development Labs Inc., which hosted the summit.

Major contributors to Xen include Hewlett-Packard Co. and Intel Corp., said Ian Pratt, founder of the Xen project and a senior lecturer at the University of Cambridge Computer Laboratory in England, where the 3-year-old open-source project is based.

IBM employees who work at the company's Linux Technology Center have also contributed to the Xen project, an IBM spokesman said.

Like the leading commercial offering from EMC Corp.'s VMware Inc. division, Xen can execute multiple virtual machines, each running its own operating system, on a single server—although the two products work differently from a technical standpoint.

To use Xen today, companies must download either a software patch or a prebuilt operating system kernel that includes the patch from the Xen project's Web site. Thus far, Xen has attracted interest from some hosting companies and "the sophisticated IT department which already is heavily into Linux," Pratt said.
Dan Kusnetzky, an analyst at IDC, views the need for users to install a kernel patch as a major inhibitor to Xen's adoption. Most corporate users get Linux from distributors such as Red Hat Inc. and Novell Inc., and if they patch the kernel, their systems will no longer be supported unless the vendors agree to accept the patch, he said.
Both Red Hat and Novell said last month that they plan to include server virtualization technology in their versions of the operating system and that Xen is a contender .

Mike Prince, CIO at Burlington Coat Factory Warehouse Corp. in Burlington, N.J., said he's less worried about Linux distributors than he is about application vendors, which can be "finicky about what they'll support."

A Linux user since 1999, Burlington Coat plans to test Xen as part of an effort to consolidate underutilized development and test systems and possibly some application servers as well, Prince said. The only reason the retailer hasn't already experimented with Xen is that it didn't know about the project until the past month, he added.