Whonix VirtualBox/KVM Live-mode!
Whonix now has the option of booting into a live system . When live-mode is chosen, all write operations will go to RAM instead of the hard disk. The primary objective of live-mode is to prevent malware from gaining a persistent foothold and to return the system to its state prior to booting.
Live mode is not amnesic; in particular, memory forensics has not been taken into account!
System with low resources:
If Whonix is running on a system will low RAM it is recommended that all non-essential processes are shutdown on the host. This will free up memory for virtual machine allocation, if needed.
Configuration instructions for live-mode:
https://whonix.org/wiki/Whonix_Live#Live-mode_Configuration
Note: Live-mode is currently unsupported with Qubes-Whonix. In Qubes R4, Qubes DisposableVMs are a suitable alternative, as well as the Qubes Live USB.
Follow Whonix live-mode Development:
Thanks to @Algernon and everyone else who made live-mode possible.