title: Errr 'mongo.js:L112 Error: couldn't connect to server 127.0.0.1:27017 at src/mongo/shell/mongo.js:L112'
body: <p>I can't connect to <a href="http://en.wikipedia.org/wiki/MongoDB" rel="noreferrer">MongoDB</a>. In Ubuntu it works, but I'm working in <a href="http://en.wikipedia.org/wiki/CentOS" rel="noreferrer">CentOS</a> now. This is the error message:</p>
  
  <blockquote>
    <p>MongoDB shell version: 2.4.2<br/>
    connecting to: test<br/>
    Sat Apr 20 07:22:09.390 JavaScript execution failed: Error: couldn't connect to server 127.0.0.1:27017 at src/mongo/shell/mongo.js:L112<br/>
    exception: connect failed</p>
  </blockquote>
  
  <p>I tried removing the <code>mongod.lock</code> file, but it doesn't work.</p>