title: Where Does the HDFS Account for Triple Replication in Usage Reports?
body: <p>In the latest version of most Hadoop distributions, the HDFS usage reports seem to report on space without accounting for the replication factor, correct?  </p>
  
  <p>When one looks at the Namenode Web UI and/or runs the 'hadoop dfsadmin -report' command, one can see a report that looks something like this:</p>
  
  <pre><code>Configured Capacity: 247699161084 (230.69 GB)
  Present Capacity: 233972113408 (217.9 GB)
  DFS Remaining: 162082414592 (150.95 GB)
  DFS Used: 71889698816 (66.95 GB)
  DFS Used%: 30.73%
  Under replicated blocks: 40
  Blocks with corrupt replicas: 6
  Missing blocks: 0
  </code></pre>
  
  <p>Based on the machine sizes of this cluster, it seems that this report does NOT account for triple replication...  I.E.  If I place a file on the HDFS, I should account for the triple replication myself.</p>
  
  <p>For example, if I placed a 50GB file on the HDFS, would my HDFS be dangerously close to full (since it seems that file would be replicated 3 times, using up the 150GB that currently remain)?</p>