Subdirectores are based on your JanusGraph base install directory. These files assumes a base directory of /opt/janusgraph-0.1.1-hadoop2
I'm using the currently available janusgraph-0.1.1-hadoop2 distro available from JanusGraph with a mixin from information I got from the TINKERPOP-(980) issue. The latest gremlin-server.sh discussed there can be found here
Create the janusgraph-rest.service and janusgraph-websoc.service in /etc/systemd/system, ensuring that the ExecStart, ExecStop an PIDFile parameters point to the apropriate directories on your system. It's pretty important to use the full path names where they are used in these files, Janusgraph and Gremlin server doesn't play well in some cases.
Type the following at the command promt:
sudo systemctl enable janusgraph-rest
sudo systemctl enable janusgraph-websoc
sudo systemctl start janusgraph-rest
sudo systemctl start janusgraph-websoc