title: Data-Node Does Not Start
body: <p>I have trouble starting my Hadoop data-node. I did all the research that I could and none of the methods were helpful in solving my issue. Here's my terminal console output when I try to start it using </p>
  
  <pre><code>hadoop datanode -start
  </code></pre>
  
  <p>This is what happens:</p>
  
  <pre><code>root@Itanium:~/Desktop/hadoop# hadoop datanode -start
  Warning: $HADOOP_HOME is deprecated.
  
  13/09/29 22:11:42 INFO datanode.DataNode: STARTUP_MSG: 
  /************************************************************
  STARTUP_MSG: Starting DataNode
  STARTUP_MSG:   host = Itanium/127.0.1.1
  STARTUP_MSG:   args = [-start]
  STARTUP_MSG:   version = 1.2.1
  STARTUP_MSG:   build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.2 -r 1503152; compiled by 'mattf' on Mon Jul 22 15:23:09 PDT 2013
  STARTUP_MSG:   java = 1.7.0_25
  ************************************************************/
  Usage: java DataNode
             [-rollback]
  13/09/29 22:11:42 INFO datanode.DataNode: SHUTDOWN_MSG: 
  /************************************************************
  SHUTDOWN_MSG: Shutting down DataNode at Itanium/127.0.1.1
  ************************************************************/
  root@Itanium:~/Desktop/hadoop# jps
  31438 SecondaryNameNode
  32013 Jps
  31818 TaskTracker
  1146 Bootstrap
      31565 JobTracker
      30930 NameNode
  
  root@Itanium:~/Desktop/hadoop# 
  </code></pre>
  
  <p>As we can see the DataNode attempts to start but then shuts down. All the while I have been having trouble with NameNode starting up. I used to fix this by manually starting it using </p>
  
  <pre><code>start-dfs.sh
  </code></pre>
  
  <p>And now the problem is with DataNode. I really would appreciate all your help in resolving this issue.</p>
  
  <p>And one more generic question. Why is Hadoop displaying such inconsistent behavior. I am sure I did not change any of the *-site.xml settings.</p>