ovf

OVF, or Open Virtualization Format, is an open standard for packaging and distributing virtual appliances and virtual machines. It was developed by the Distributed Management Task Force (DMTF) to improve portability of VM images across different virtualization platforms and cloud environments. An OVF package describes the virtual system, its hardware requirements, network interfaces, and deployment parameters in a structured XML document known as the OVF descriptor, typically with a .ovf extension.

Alongside the descriptor, an OVF package may include one or more virtual disk images (such as VMDK or VHD) and optional ancillary files. A manifest (.mf) can accompany the package to verify integrity via cryptographic hashes, and a certificate may be used to sign the package to establish authenticity. The OVF format supports multiple virtual machines within a single package, multiple virtual disks, and detailed deployment metadata, including hardware resources, network connections, and operating system information.

OVF is designed to be hypervisor-agnostic, with support implemented by many major platforms, including VMware vSphere, Microsoft Hyper-V, Oracle VirtualBox, and KVM-based environments. A common distribution form is the Open Virtual Appliance (OVA), a tar archive that bundles the OVF descriptor, disk images, and optional manifest and signatures for convenient distribution.

Overall, OVF provides a portable, description-based packaging model intended to improve interoperability and reproducibility in virtual appliance deployments across diverse hypervisors.