What is a .vmdk file? (VMDK)

A .vmdk file is a VMware virtual disk, the file that stores a virtual machine's hard drive. It is the VMware equivalent of Hyper-V's VHDX, and is widely supported by other hypervisors too.

What is a .vmdk file used for?

Monolithic sparse VMDKs start with the magic KDMV, while some VMDKs are a small text descriptor pointing to separate data extents. Either way the file represents a whole virtual disk.

VMDK is one of the most portable VM disk formats: VirtualBox, qemu and cloud import tools all read it, which is why it is common for distributing appliances.

How to open a .vmdk file

The .vmdk format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list. For a step-by-step walkthrough, see how to open a .vmdk file.

Windows

VMware Workstation
VirtualBox
qemu-img

macOS

VMware Fusion
VirtualBox
qemu-img

Linux

qemu / qemu-img
VirtualBox
VMware

How to convert a .vmdk file

You can convert a .vmdk file to vhd, vhdx, img, qcow2 using a conversion tool or the export menu of an app that opens it.

.vmdk file signature (magic bytes)

Programs recognise a .vmdk file by the bytes at the start of the file, not by its name. These are the signatures for VMDK. For a full breakdown, see the VMDK file signature page.

Hex signature	Offset	Note
4B 44 4D 56	0	'KDMV' (sparse); some VMDKs start with a text descriptor

See the full magic-numbers reference for every format.

Frequently asked questions