title: mongodb not starting on ubuntu 18.04
body: <p>I'm running ubuntu 18.04 on windows 10. I run 'mongod' on cli and mongodb starts normally. I then try to run 'mongo' and I get this error :</p>
  <pre><code>MongoDB shell version v4.0.2
  connecting to: mongodb://127.0.0.1:27017
  2018-09-01T20:30:37.462+0800 E QUERY    [js] Error: couldn't connect to server 127.0.0.1:27017, connection attempt failed: SocketException: Error connecting to 127.0.0.1:27017 :: caused by :: Connection refused :
  connect@src/mongo/shell/mongo.js:257:13
  @(connect):1:6
  exception: connect failed.
  </code></pre>
  <p>I don't understand how one works and the other doesn't. I do think it is from either file permissions or an issue with the localhost.</p>