What is OVF?
With the rapid adoption of virtualization, there is a great need for a standard way to package and distribute virtual machines. VMware and other leaders in the virtualization field have created the Open Virtualization Format (OVF), a platform independent, efficient, extensible, and open packaging and distribution format for virtual machines.
OVF enables efficient, flexible, and secure distribution of enterprise software, facilitating the mobility of virtual machines and giving customers vendor and platform independence. Customers can deploy an OVF formatted virtual machine on the virtualization platform of their choice.
With OVF, customers’ experience with virtualization is greatly enhanced, with more portability, platform independence, verification, signing, versioning, and licensing terms. OVF lets you:
- Improve your user experience with streamlined installations
- Offer customers virtualization platform independence and flexiblity
- Create complex pre-configured multi-tiered services more easily
- Efficiently deliver enterprise software through portable virtual machines
- Offer platform-specific enhancements and easier adoption of advances in virtualization through extensibility
The portability and interoperability inherent in OVF will enable the growth of the virtual appliance market as well as virtualization as a whole.
Package and Distribute OVF-Formatted Virtual Machines
The Open Virtualization Format (OVF) describes an open, secure, portable, efficient, and flexible format for the packaging and distribution of one or more virtual machines. Key features and benefits of OVF:
Enables optimized distribution- OVF enables the portability and distribution of virtual appliances. In addition to support for compression for more efficient package transfers, OVF supports industry standard content verification and integrity checking, and provides a basic scheme for the management of software licensing.
Provides a simple, automated user experience – OVF offers a robust and user-friendly approach to streamline the installation process. During installation, meta-data in the OVF file can be used by a customer’s management infrastructure to validate the entire package and confidently determine whether each virtual machine should be installed. Compatibility with the local virtual hardware will also be verified.
Supports both single and multi virtual machine configurations – Virtual appliance solutions stacks may consist of one or many virtual appliances. With OVF, Software Developers can configure complex multi-tiered services consisting of multiple interdependent virtual appliances.
Enables portable VM packaging - OVF is virtualization platform independent, while also enabling platform-specific enhancements to be captured. It supports the full range of virtual hard disk formats used for virtual machines today, and is extensible to deal with future formats that are developed. Virtual machine properties are captured concisely and accurately.
Affords vendor and platform independence - OVF does not rely on the use of a specific host platform, virtualization platform, or guest operating system.
Supports localization – OVF supports user visible descriptions in multiple locales, and supports localization of the interactive processes during installation of an appliance. This allows a single packaged appliance to serve multiple market opportunities
Offers future extensibility - OVF is extensible. It is designed to be extended as the industry moves forward with virtual appliance technology.
How does VMDK compare to OVF?
VMDK is a file format that only encodes a single virtual disk from a virtual machine. A VMDK does not contain information about the virtual hardware of a machine, such as the CPU, memory, disk, and network information. A virtual machine may include multiple virtual disks or VMDKs. An administrator who wishes to deploy a virtual disk must then configure all of this information, often manually, using incomplete documentation.
The OVF format, on the other hand, provides a complete specification of the virtual machine. This includes the full list of required virtual disks plus the required virtual hardware configuration, including CPU, memory, networking, and storage. An administrator can quickly provision this virtual machine into virtual infrastructure with little or no manual intervention. In addition, the OVF is a standards-based, portable format that allows the user to deploy this virtual machine in any hypervisor that supports OVF.
DMTF Virtualization Management (VMAN) Initiative
Visit the DMTF VMAN Initiative site for up to date OVF whitepapers, technical notes, specifications and more.
- DSP0243 1.1.0 Open Virtualization Format Specification
- DSP2017 1.0.0 Open Virtualization Format White Paper
- DSP2021 1.0.0 Open Virtualization Format Examples .tar file
- DSP8023 1.1.0 Open Virtualization Format Envelope Schema
- DSP8027 1.1.0 Open Virtualization Format Environment Schema
VMware OVF Tool
VMware OVF Tool is a command line utility that supports importing and exporting of OVF packages for a wide variety of VMware platforms, including VMware Workstation, VMware Server 2.0, vSphere 4.0, and earlier versions of VMware ESX Server and VMware VirtualCenter.