Red Hat Officials: Not Feeling Xen

The move to embed virtualization technology deep into the linux kernel is stuck on the workbench.

The move to embed virtualization technology deep into the Linux kernel is stuck on the workbench.

Despite earlier optimistic predictions by Red Hat executives and others in the open-source community that the work would take just a couple of months, they now say that the technology is still "far from ready for inclusion in the kernel."

Virtualization, which allows IT managers to run multiple copies of Linux on a single server, is key to many enterprise consolidation strategies. The problem with bringing virtualization to the Linux kernel is that the code for the Xen Project—an open-source effort to create virtual machines—wont stand still.

"I am an eternal optimist, but I really did not appreciate how extensively and rapidly the Xen code changes," Brian Stevens, Red Hats chief technology officer, told eWEEK at the March 14 launch of the companys Integrated Virtualization strategy in San Francisco.

For Red Hat, of Raleigh, N.C., a big part of the strategy is making virtualization an integrated part of the Linux system itself so that the system understands it is virtualized and can better participate in its management.

Stevens said that there are hundreds of changes on Xen code each week and that the Xen Projects latest version—Xen 3.0, released in December—is "still far from ready for inclusion in the kernel."

In October, Stevens took up the task of driving forward the merging of Xen into the Linux kernel, an initiative that had previously run out of steam. At the time, Stevens said the effort wasnt "a long-term project at all."

Today, it is more likely that components of the Xen virtualization technology will be merged into the kernel over time, starting with the Xen interfaces, rather than all of it as a single submission, Stevens said.

The upshot is that Red Hat will have to support Xen "out of tree"—which means it wont be supported or included in the stable Linux kernel or in the development kernel—for RHEL (Red Hat Enterprise Linux) Version 5. RHEL 5 is scheduled for general availability before the end of this year and will feature fully integrated virtualization.

Andrew Morton, the current maintainer of the Linux 2.6 kernel, who works for Open Source Development Labs, in Beaverton, Ore., told eWEEK he hasnt been hearing much on the Xen submission front. "I dont know what people have been doing lately—nothing has come my way," Morton said.