title: How to add an hard disk to hadoop
body: <p>I installed Hadoop 2.4 on Ubuntu 14.04 and now I am trying to add an internal sata HD to the existing cluster.</p>
  
  <p>I have mounted the new hd in /mnt/hadoop and assigned its ownership to the hadoop user </p>
  
  <p>Then I tried to add it to the configuration file as follow:</p>
  
  <pre><code>&lt;configuration&gt;
     &lt;property&gt;
         &lt;name&gt;dfs.replication&lt;/name&gt;
         &lt;value&gt;2&lt;/value&gt;
     &lt;/property&gt;
  
     &lt;property&gt;
         &lt;name&gt;dfs.name.dir&lt;/name&gt;
         &lt;value&gt;file:///home/hadoop/hadoopdata/hdfs/namenode, file:///mnt/hadoop/hadoopdata/hdfs/namenode&lt;/value&gt;
     &lt;/property&gt;
  
     &lt;property&gt;
         &lt;name&gt;dfs.data.dir&lt;/name&gt;
         &lt;value&gt;file:///home/hadoop/hadoopdata/hdfs/datanode, file:///mnt/hadoop/hadoopdata/hdfs/datanode&lt;/value&gt;
     &lt;/property&gt;
  &lt;/configuration&gt;
  </code></pre>
  
  <p>Afterwards, I started the hdfs:</p>
  
  <pre><code>Starting namenodes on [localhost]
  localhost: starting namenode, logging to /home/hadoop/hadoop/logs/hadoop-hadoop-namenode-hadoop-Datastore.out
  localhost: starting datanode, logging to /home/hadoop/hadoop/logs/hadoop-hadoop-datanode-hadoop-Datastore.out
  Starting secondary namenodes [0.0.0.0]
  0.0.0.0: starting secondarynamenode, logging to /home/hadoop/hadoop/logs/hadoop-hadoop-secondarynamenode-hadoop-Datastore.out
  </code></pre>
  
  <p>It seems that it does not fire up the second hd</p>
  
  <p>This is my core-site.xml</p>
  
  <pre><code>&lt;configuration&gt;
     &lt;property&gt;
         &lt;name&gt;fs.default.name&lt;/name&gt;
         &lt;value&gt;hdfs://localhost:9000&lt;/value&gt;
     &lt;/property&gt;
  &lt;/configuration&gt;
  </code></pre>
  
  <p>In addition I tried to refresh the namenode and I get a connection problem:</p>
  
  <pre><code>Refreshing namenode [localhost:9000]
  refreshNodes: Call From hadoop-Datastore/127.0.1.1 to localhost:9000 failed on connection exception: java.net.ConnectException: Connection refused; For more details see:  http://wiki.apache.org/hadoop/ConnectionRefused
  Error: refresh of namenodes failed, see error messages above.
  </code></pre>
  
  <p>In addition, I can't connect to the Hadoop web interface.
  It seems that I have two related problems:</p>
  
  <pre><code> 1) A connection problem
   2) I cannot connect to the new installed hd
  </code></pre>
  
  <p>Are these problem related?
  How can I fix these issues?</p>
  
  <p>Thanks </p>
  
  <p><strong>EDIT</strong></p>
  
  <p>I can ping the localhost and I can access localhost:50090/status.jsp</p>
  
  <p>However, I cannot access 50030 and 50070</p>