Sun christens its Xen-based virtualization xVM

SAN FRANCISCO--Sun Microsystems, a longtime participant in the Xen open-source hypervisor project, has named its Solaris-based offshoot xVM, short for x86 Virtual Machine.

"Because Xen is trademarked, we don't want to call the code we've implemented Xen," said Marc Hamilton, Sun's vice president of Solaris marketing, on Wednesday. It works only on computers with x86 chips such as Intel's Xeon; those with Sun's newer UltraSparc processors use an equivalent technology called logical domains, or LDoms.

Virtualization, blossoming as a technology foundation for x86 servers, lets a single computer run multiple operating systems simultaneously to increase data center efficiency and flexibility. It's a decades-old technology, but it's now spreading like wildfire across the x86 server world. Most of the flames are coming from newly public VMware, which held its VMworld conference here this week.

Xen governs how virtual machines get access to hardware resources, typically relying on Linux for technology used to actually communicate with that hardware. xVM, though, is a variation that uses Sun's Solaris operating system instead. Hamilton boasted on his blog last week that Sun's variant shows some performance improvements over Linux-based Xen.

xVM is a part of the open-source incarnation of Solaris, OpenSolaris, but has yet to be moved to the slower-moving and fully supported Solaris geared for production use. But it could be arriving in production environments soon in one form called an appliance.

VMware has touted virtual appliances as a way to neatly package operating systems with higher-level software. Sun sees the same potential but takes it a step further, with hardware thrown into the mix, Hamilton said.

"We expect that (xVM) will first show up in the form of virtual appliances in the next 12 months," Hamilton said. "There is a lot of complexity to running any virtual environment."

xVM will be fully integrated into Solaris with the first release of Project Indiana, the Linux-like incarnation of OpenSolaris led by Debian Linux founder Ian Murdock. The first version of Indiana is due about March 2008, Hamilton said.

One prominent feature of Indiana is packaging software designed to make it easier to download and install new software or updates to existing packages. The software, called Universal Packaging System (UPS), resembles the apt-get software used in Debian and Debian offshoots such as Ubuntu.