ID:2385246
 
(See the best response by Ter13.)
Is it possible to keep the server running actively when no players are online?
Best response
Players shouldn't affect the server's status unless you have sleep_offline set.

In reality, even if sleep_offline is set, the vast majority of games written in DM wouldn't respect that setting anyway, because nobody who uses DM can write tight enough code to keep the scheduler clean.

Those who ARE incidentally capable of doing so, probably won't care enough to take advantage of the feature, understanding that the effort probably isn't even worth the benefit.
If you're running on Linux/Unix don't use the "once" option, if you are that is :)

-once        (shutdown after users log out)