Solid read on QubesOS (links below). Considering putting it on my backup server just for testing. It seems to be a good testing ground to put a second PostgreSQL and drop it in a VPN and/or Tor. Some VPNs allow ports to be open in certain locations. Playing with replication methods in PostgreSQL today.

https://www.linuxjournal.com/content/weekend-reading-qubes
https://www.whonix.org/wiki/Qubes