title: how start elasticsearch with debug / verbose
body: <p>i have a really hard time setting up JDBC river mysql connector with my elasticsearch installation</p>
  
  <p>first i follow all the <a href="https://github.com/jprante/elasticsearch-river-jdbc" rel="noreferrer">https://github.com/jprante/elasticsearch-river-jdbc</a> howto</p>
  
  <p>diffrence is where i install the elasticsearch from RPM repository via yum install elasticsearch, somehow it installed my elasticsearch in /usr/share/elasticsearch but the config are in /etc/elasticsearch</p>
  
  <p>the problem lies when i installed the jdbc plugin, after installed already checked via <code>plugin -l</code> and yes there is a jdbc driver, but when i run bin/elasticsearch</p>
  
  <p>it shows nothing helpfull just like</p>
  
  <p><img src="https://i.stack.imgur.com/3Zvh1.png" alt="enter image description here"></p>
  
  <p>is it working? how could i show [DEBUG] and [INFO] ? </p>