Zerofree Utility

[Keith]

For readers as easily confused as I am, the following links may help to understand the various mystical initials used here:
VDI: "Virtual Desktop Infrastructure" - https://www.javatpoint.com/what-is-vdi
VM: "Virtual Machine" - https://www.fosslinux.com/43294/what-is-a-virtual-machine-and-why-to-use-it.htm
VB: "VirtualBox" - https://www.oracle.com/uk/virtualization/virtualbox/

[MattC]

Thanks Keith.  I spend some time discussing things with others who talk almost exclusively in abbreviations.

Old joke: "I hate people who use TLAs!" (three letter abbreviations) 

I'll have to get out of the habit, or explain definitively what I'm discussing.

Thanks.