title: How to set individual data node directories on individual data nodes in Hadoop?
body: <p>I’m learning the basics of Hortonworks and running a small cluster with the following specs:</p>
  
  <ul>
  <li>3 Amazon EC2 Nodes (each is both datanode and name node)</li>
  <li>Setup through Ambari</li>
  <li>Node1 has extra storage at /mnt/vol1 (mounted hard drive)</li>
  </ul>
  
  <p>Now, when adding /mnt/vol1 to dfs.datanode.data.dir (through Ambari) each node gets a copy of the vol1 directory, even if they don’t exist. Will blocks be stored in these directories on the other datanodes too? How can I just add extra storage for a single datanode and not the others?</p>