title: Hadoop - namenode is not starting up
body: <p>I am trying to run hadoop as a root user, i executed namenode format command <code>hadoop namenode -format</code> when the Hadoop file system is running.</p>
  
  <p>After this, when i try to start the name node server, it shows error like below</p>
  
  <pre><code>13/05/23 04:11:37 ERROR namenode.FSNamesystem: FSNamesystem initialization failed.
  java.io.IOException: NameNode is not formatted.
          at org.apache.hadoop.hdfs.server.namenode.FSImage.recoverTransitionRead(FSImage.java:330)
          at org.apache.hadoop.hdfs.server.namenode.FSDirectory.loadFSImage(FSDirectory.java:100)
          at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.initialize(FSNamesystem.java:411)
  </code></pre>
  
  <p>I tried to search for any solution, but cannot find any clear solution.</p>
  
  <p>Can anyone suggest?</p>
  
  <p>Thanks.</p>