Converting Between Virtual Disk Formats

In addition to its own native VDI virtual disk file format, Sun’s VirtualBox supports both Virtual PC’s VHD virtual disk file format and WMWare’s VMDK virtual disk file formats, AND has the ability to convert your virtual disks between these formats.

What they don’t tell you however, is that the virtual disk must be fully removed from the VirtualBox Virtual Media Manager before the command will run successfully (if you have been using the virtual disk previously in a virtual machine in VirtualBox).

For example, the command to convert a VMDK to a VHD is:

"c:\program files\sun\VirtualBox\VBoxManage.exe" clonehd "my.vhd" "my.vmdk" –format vmdk

Below is the documentation from section 8.16 VBoxManage clonehd:

VBoxManage clonehd         <uuid>|<filename> <outputfile>
                           [--format VDI|VMDK|VHD|RAW|<other>]
                           [--variant Standard,Fixed,Split2G,Stream,ESX]
                           [--type normal|writethrough|immutable]

where the parameters mean:


Allow to choose a file format for the output file different from the file format of the input file.


Allow to choose a file format variant for the output file. It is a comma-separated list of variant flags. Not all combinations are supported, and specifying inconsistent flags will result in an error message.


Only honored if –remember is also specified. Defines what kind of hard disk type this image should be.


Keep the destination image registered after it was successfully written.


One Response to Converting Between Virtual Disk Formats

  1. Cd-MaN says:

    I usually use qemu-img ( ) to convert between different virtual HDD image formats. It knows a whole lot of formats (VPC, VMWare 5 and 6, etc) and if all else fails, it can convert to RAW files which can be read by pretty much everything (the disadvantage being the size of the resulting file).

    You can find readily compiled versions of Qemu (including qemu-img) for Windows here:

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