title: unable to run start-dfs.sh
body: <p>I am unable to run <code>start-dfs.sh</code></p>
  
  <pre><code>ubuntu@UBUNTU:~$ start-dfs.sh
  14/10/19 19:26:50 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
  Starting namenodes on [localhost]
  localhost: ssh: connect to host localhost port 22: Connection refused
  localhost: ssh: connect to host localhost port 22: Connection refused
  Starting secondary namenodes [0.0.0.0]
  0.0.0.0: ssh: connect to host 0.0.0.0 port 22: Connection refused
  14/10/19 19:27:19 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
  ubuntu@UBUNTU:~$
  </code></pre>
  
  <p>I did the following while installing hadoop:</p>
  
  <pre><code>ssh-keygen -t rsa -P ''
  cat ~/.ssh/id_rsa.pub &gt;&gt; ~/.ssh/authorized_keys
  </code></pre>