If you change the opennms-datasources file to point to a IP other than localhost, the script exists with the following message:
[opennms@localhost daemon]$ sudo /opt/opennms/bin/opennms start
Starting OpenNMS: OpenNMS runs better if you start up the database first.
Verified this today on 3 installations during class that were trying to separate the DB server from the NMS. Just verified on a local system by configuring opennms to connect to an actual IP on the local system. This failed also. No logs! Just an exit code of 1 is returned from the boostrap.jar main when passed the "check" parameter.