title: Hadoop 2.2.0 : "name or service not known" Warning
body: <p>My aim is to run hadoop 2.2.0 on Ubuntu 12.4 . i was able to do it but when i run following command: 
  <strong><em>rushi@ubuntu:/usr/local/hadoop$ sbin/start-dfs.sh</em></strong> </p>
  
  <p>my dfs is starting namenode, scondarynamenode and also datanode but the problem is i am getting following Warning </p>
  
  <pre><code>rushi@ubuntu:/usr/local/hadoop$ sbin/start-dfs.sh    
  14/01/24 12:05:46 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
      Starting namenodes on [Java HotSpot(TM) 64-Bit Server VM warning: You have loaded library /usr/local/hadoop-2.2.0/lib/native/libhadoop.so.1.0.0 which might have disabled stack guard. The VM will try to fix the stack guard now.
      It's highly recommended that you fix the library with 'execstack -c &lt;libfile&gt;', or link it with '-z noexecstack'.
      localhost]
      sed: -e expression #1, char 6: unknown option to `s'
      Java: ssh: Could not resolve hostname Java: Name or service not known
      library: ssh: Could not resolve hostname library: Name or service not known
      warning:: ssh: Could not resolve hostname warning:: Name or service not known
      which: ssh: Could not resolve hostname which: Name or service not known
      have: ssh: Could not resolve hostname have: Name or service not known
      might: ssh: Could not resolve hostname might: Name or service not known
      You: ssh: Could not resolve hostname You: Name or service not known
      loaded: ssh: Could not resolve hostname loaded: Name or service not known
      Server: ssh: Could not resolve hostname Server: Name or service not known
      HotSpot(TM): ssh: Could not resolve hostname HotSpot(TM): Name or service not known
      have: ssh: Could not resolve hostname have: Name or service not known
      64-Bit: ssh: Could not resolve hostname 64-Bit: Name or service not known
      VM: ssh: Could not resolve hostname VM: Name or service not known
      disabled: ssh: Could not resolve hostname disabled: Name or service not known
      VM: ssh: Could not resolve hostname VM: Name or service not known
      stack: ssh: Could not resolve hostname stack: Name or service not known
      The: ssh: Could not resolve hostname The: Name or service not known
      fix: ssh: Could not resolve hostname fix: Name or service not known
      try: ssh: Could not resolve hostname try: Name or service not known
      guard.: ssh: Could not resolve hostname guard.: Name or service not known
      to: ssh: Could not resolve hostname to: Name or service not known
      now.: ssh: Could not resolve hostname now.: Name or service not known
      will: ssh: Could not resolve hostname will: Name or service not known
      that: ssh: Could not resolve hostname that: Name or service not known
      stack: ssh: Could not resolve hostname stack: Name or service not known
      the: ssh: Could not resolve hostname the: Name or service not known
      you: ssh: Could not resolve hostname you: Name or service not known
      -c: Unknown cipher type 'cd'
      guard: ssh: Could not resolve hostname guard: Name or service not known
      It's: ssh: Could not resolve hostname It's: Name or service not known
      highly: ssh: Could not resolve hostname highly: Name or service not known
      fix: ssh: Could not resolve hostname fix: Name or service not known
      recommended: ssh: Could not resolve hostname recommended: Name or service not known
      or: ssh: Could not resolve hostname or: Name or service not known
      the: ssh: Could not resolve hostname the: Name or service not known
      library: ssh: Could not resolve hostname library: Name or service not known
      link: ssh: Could not resolve hostname link: Name or service not known
      'execstack: ssh: Could not resolve hostname 'execstack: Name or service not known
      with: ssh: Could not resolve hostname with: Name or service not known
      &lt;libfile&gt;',: ssh: Could not resolve hostname &lt;libfile&gt;',: Name or service not known
      it: ssh: Could not resolve hostname it: Name or service not known
      noexecstack'.: ssh: Could not resolve hostname noexecstack'.: Name or service not known
      with: ssh: Could not resolve hostname with: Name or service not known
      '-z: ssh: Could not resolve hostname '-z: Name or service not known
      localhost: starting namenode, logging to /usr/local/hadoop-2.2.0/logs/hadoop-rushi-namenode-ubuntu.out
      localhost: starting datanode, logging to /usr/local/hadoop-2.2.0/logs/hadoop-rushi-datanode-ubuntu.out
      Starting secondary namenodes [Java HotSpot(TM) 64-Bit Server VM warning: You have loaded library /usr/local/hadoop-2.2.0/lib/native/libhadoop.so.1.0.0 which might have disabled stack guard. The VM will try to fix the stack guard now.
      It's highly recommended that you fix the library with 'execstack -c &lt;libfile&gt;', or link it with '-z noexecstack'.
      0.0.0.0
  
  ]
  </code></pre>
  
  <p>What may be the problem and how to solve it?
  Please help me</p>