Most dRuby examples are using a multi machine/terminal/main process example. This example is for those like me, who need to harvest dRuby's power in a "single entry point" script.
I will be short on the topic as you too only seeking the resolution to the problem in the title. This tutorial is based on using Vmware Workstation 11 on Windows 8.1 host using an Ubuntu 14.04 guest. Note : you have to have the vmware tools, client additions installed on the quest machine! First go to the Vmware client's terminal when you are ready to shrink it down and type: sudo vmware-toolbox-cmd disk list This will give you the mount points that can be shrinked individually. For me I will only go with shrinking the main disk with "/" (root). First lets wipe the free space clean so the shrinker will know what is free to get rid of: sudo vmware-toolbox-cmd disk wipe / To shrink: sudo vmware-toolbox-cmd disk shrink / That's it, after the process in my case I've had a 4.4G file shrinked down to 1.7G, which is much closer to what the client OS saw (1.5G).