create the file /root/bin/web2pytest.sh to check if web2py runs and start web2py if it is not running

if
        ! ` netcat -z localhost 8000 `
        then pgrep -flu myusername web2py | cut -d\  -f1 | xargs kill > /dev/null  2>&1
        chown myusername: /var/log/web2py.log
        su myusername -c 'cd /home/myusername/web2py && ./web2py.py -p 8000 -a password 2>&1 >> /var/log/web2py.log'
        sleep 3
        if 
                ! ` netcat -z localhost 8000 `
                then echo "web2py/sysbio could not be started!"
                else echo "web2py/sysbio was restarted"
        fi
fi

now add the following line to crontab to execute the script every 3 minutes

*/3 * * * * /root/bin/web2pytest.sh > /dev/null

thanks to Ivo Maintz, you da best :)