title: Hadoop: require root's password after enter "start-all.sh"
body: <p>I have installed Hadoop and SSH on my laptop. "ssh localhost" works fine. After formatting HDFS, I tried to start hadoop. </p>
  
  <pre><code>munichong@GrindPad:~$ sudo /usr/sbin/start-all.sh
  starting namenode, logging to /var/log/hadoop/root/hadoop-root-namenode-GrindPad.out
  root@localhost's password: 
  root@localhost's password: localhost: Permission denied, please try again.
  
  localhost: Permission denied (publickey,password).
  </code></pre>
  
  <p>It requires password. My role is "munichong". But munichong's password does not work here. Here, my role has changed to "root". I do not know whether I missed something here.</p>
  
  <p>Is there anyone can help me?</p>
  
  <p>Thanks!</p>