Standard coming to virtualization format

Virtualization and server companies are cooperating to standardize the format used to save virtual machine images to disk.

Major virtualization companies are cooperating to bring some simplicity to the world of their mutual interest, the format used to save virtual machine images to disk.

Cooperating in the effort are VMware, XenSource and Microsoft, which today have separate software for the task of running multiple virtual machines on one computer and separate formats for storing those virtual machines. That storage is an important part of tasks such as backing up data, installing fresh virtual machines from a template, or moving one quiescent virtual machine from one physical computer to another.

Major server companies Hewlett-Packard, Dell and IBM also are participating in the effort, which is taking place within a group called the Distributed Management Task Force that's standardized other server technologies as well.

The move is a notable display of cooperation among competitors. However, the standard doesn't address other aspects of virtualization that could be standardized, such as interfaces to start, stop, move and otherwise control virtual machines.

The task force announced the move just as a major virtualization conference, VMworld, begins in San Francisco.

The proposed format, called the Open Virtual Machine Format (OVF), doesn't replace the three existing standards, but instead wraps them in a standard package of XML that includes necessary information to install and configure the virtual machines.

"This allows any virtualization platform that implements the standard to correctly install and run the virtual machines," the task force said.

The standard permits integrity checking, too, so those with virtual machines stored as OVF files can protect against tampering.