title: Hadoop Ambari cannot confirm hosts
body: <p>I tried to use Ambari to manage the installation and maintenance of the Hadoop cluster.</p>
  
  <p>After I started ambari server, I use the web page to set up Hadoop cluster.</p>
  
  <p>But at the 3rd step-- confirm hosts, the error shows below</p>
  
  <p>And I check the log at /var/log/ambari-server, I found:</p>
  
  <blockquote>
    <p>INFO:root:BootStrapping hosts ['qiao'] using /usr/lib/python2.6/site-packages/ambari_server cluster primary OS: redhat6 with user 'root' sshKey File /var/run/ambari-server/bootstrap/1/sshKey password File null using tmp dir /var/run/ambari-server/bootstrap/1 ambari: master; server_port: 8080; ambari version: 1.4.1.25</p>
    
    <p>INFO:root:Executing parallel bootstrap</p>
    
    <p>ERROR:root:ERROR: Bootstrap of host qiao fails because previous action finished with non-zero exit code (1)</p>
    
    <p>INFO:root:Finished parallel bootstrap</p>
  </blockquote>