OVF - The New Prescription for Hypervisor Interoperability Pain

Following the dozens of announcements at VMworld Tuesday, one topic continued to creep into nearly every discussion - Open Virtual Machine Format (OVF). The Distributed Management Task Force (DMTF) announced the OVF standard yesterday, with contributions from VMware, Microsoft, XenSource, HP, and IBM included in the announcement.

OVF defines an XML wrapper that encapsulates one or more virtual machines and provides a common interface so that the VMs can run on any hypervisor that supports OVF. OVF packaging and hypervisor support is expected by the end of the year. So when OVF is supported on Xen and VMware virtualization platforms for example, a VM packaged on a VMware hypervisor can run on a Xen hypervisor, and vice-versa. ISVs wishing to ship demo versions of their software will be able to package a virtual machine or set of virtual machines using OVF, knowing that their package can run on any hypervisor.

OVF provides much more than an interoperability transport. It is extensible and includes the ability to package metadata with one or more VMs. Examples of defined metadata may be:

• Licensing information
• Resource requirements (storage, network,etc.)
• Service level requirements
• Recovery time objectives
• Port restrictions
• Access control

In other words, any requirements of a VM's environment can be packaged with a VM and follow it from server-to-server. Vendors have already noted that OVF adoption is not months away, but rather is imminent. As I see it, the OVF standard is a win for the entire virtualization industry. ISVs benefit from being able to ship a single virtualization package, compatible with all hypervisors. Organizations clearly benefit from a larger choice of virtual machine appliances for their preferred hypervisor and also from the ability to package custom metadata with each of their managed virtual machines.

Posted by: Chris Wolf