You dont have to put the & symbol to put the process in background. It will work without that. Sample configuration:

start on startup


setuid deploy
exec php /var/www/document_service/current/daemxon/archiver/run_archiver.php

start on: Ensures that on reboot of the system the script starts

respawn: Ensures that if the process is somehow killed, it starts again

setuid deploy: Sets the user that runs the process to deploy

exec: Executes the command

Original post