Description:

PowerNap is a configurable daemon that will bring a running system to
a lower power state according to a set of configuration preferences.
It acts as a sort of "screensaver" for servers, watching the process
table for activity rather than the keyboard or mouse.

PowerNap will run $ACTION when none of $PROCESSES have executed for
some number of $ABSENCE seconds. For instance, PowerNap can
automatically "pm-suspend" a system if no instance of "kvm" runs for
some contiguous block of "300" seconds.