vzvol is a zvol manager, that allows a user to create, 
format, and manage zvols in the context of use for 
virtualization. It is meant to simplify the management of
these devices, as well as allow the creation of a shim
.VMDK file to allow the use of a zvol with VirtualBox.

WWW: https://github.com/RainbowHackerHorse/vzvol