OVF vs. VMDK

OVF stands for Open Virtualization Format, a platform independent, extensible packaging and distribution format for virtual machines. It’s now a DMTF standard.

VMDK stands for Virtual Machine Disk, a format that encodes a single virtual disk for a virtual machine. It’s proprietary by VMware but whose format is publicly documented by the company. You can use VDDK to manipulate the VMDKs.

To package VMware virtual machines, both OVF and VMDK are needed. OVF includes metadata that describes the configurations of virtual machines, including CPU, memory, network, references to virtual disks, etc. Its content is very much like that of one or multiple .vmx file, and pretty small in size compared with disk images. VMDK has everything of a hard disk image and mostly huge in size. To package virtual machines for other hypervisors, you might need other disk formats like VHD from Microsoft.

Although OVF is platform independent, it does not mean you can import/export an OVF package with any disk format. For that, you may need converters, either standalone or built-in, that convert the images before importing or exporting.

Besides the vSphere Client, VMware has shipped OVF Tool for managing OVF packages. Check out here for more details.

This entry was posted in Virtualization and tagged , , . Bookmark the permalink. Post a comment or leave a trackback: Trackback URL.

2 Comments

  1. Posted April 6, 2010 at 9:54 pm | Permalink

    Great post Steve. You’ve done a good job at explaining the difference between the two file formats. I come across quite a few people that often refer to those files in the wrong context.

  2. Posted April 7, 2010 at 2:32 am | Permalink

    Thanks Paul,
    I am glad you found it’s useful.
    Steve

One Trackback

Post a Comment

Your email is never published nor shared. Required fields are marked *

*
*

You may use these HTML tags and attributes <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

  • NEED HELP?


    My consulting helps clients with virtualization and cloud computing, including VMware infrastructure automation and orchestration, vSphere management APIs, and deep product integration with hypervisors. Current training offerings include vSphere APIs training, vCenter Orchestrator training, and etc. Should you, or someone you know, need these consulting services or training, please feel free to contact me: steve __AT__ doublecloud.org.

    Me: Steve Jin, VMware vExpert who authored the VMware VI and vSphere SDK by Prentice Hall, and created the de factor open source vSphere Java API while working at VMware engineering. Companies like Cisco, EMC, NetApp, HP, Dell, VMware, are among the users of the API and other tools I developed for their products, internal IT orchestration, and test automation.