A look at the Open Virtualization Format Specification

With VMworld 2008 upon us next month, the challenges virtualization presents IT managers is top of mind for many vendors and industry organizations.

One group in particular, the Distributed Management Task Force, or DMTF, in September 2007 announced the acceptance of a draft specification that promised to simplify virtualization interoperability, security and management. According to a DMTF paper about the Open Virtualization Format Specification, the OVF "describes an open, secure, portable, efficient and extensible format for the packaging and distribution of software to be run in virtual machines (VM)."

The proposed format uses existing packaging tools to combine one or more VM together with a standards-based XML wrapper that provides the virtualization platform -- from VMware, Microsoft, Citrix, or others -- a portable package, which includes installation and configuration parameters for the VMs. The OVF could also help IT managers understand how virtual machines have been changed throughout their lifecycle. For instance, if a VM template is cloned and that clone has changed from the master template, IT managers need to know what has changed to be able to troubleshoot performance problems on the VM.

According to John Suit, Fortisphere CTO and principal founder, understanding the relationships among VMs and the history of changes a particular instance has undergone will aid IT managers looking to manage and optimize their multi-platform virtual environment. And a standard such as OVF will make it possible to track such information across heterogeneous virtualization platforms. Fortisphere develops software to prevent configuration drift and enable automated policy-based management in virtual environments.

"It's important to understand the VM you have started with, how it is now different and when there is a problem," Suit explains. "And if there is a problem, you need to know what changed so you can determine if that is the source of the problem."

The DMTF calls this ability "integrity checking," and says the OVF will help with that capability to not only manage and troubleshoot VMs but also enhance the security of the format.

"The impact of OVF will extend far beyond the participating server virtualization vendors to include the entire [independent software vendor] community," said Chris Wolf, senior analyst with Burton Group, in a press statement announcing the DMTF's acceptance of the draft specification. OVF marks a new era in virtualization -- one which includes never-seen-before interoperability in the enterprise. The whole IT community collectively stands to benefit from this landmark standard."

Companies behind the proposed standard include Dell, HP, IBM, Microsoft, VMware and XenSource (acquired by Citrix). The work-in-progress specification is set to expire September 30, 2008.Stay tuned for an update on this specification and its journey toward becoming a standard.

Denise Dubie is senior editor with Network World.