Since Ubuntu 15.10 (resp. Debian 8 "jessie"), you have to use the following command to configure your service minidlna to run at startup:

sudo systemctl enable minidlna.service

And to disable it again from starting at boot time:

sudo systemctl disable minidlna.service

This works with all service name references that you can find with ls /lib/systemd/system/*.service.

 

https://askubuntu.com/a/1139269