title: where did the configuration file stored in CDH4
body: <p>I setup a CDH4<br>
  Now I can configure the hadoop on the web page.</p>
  
  <p>I want to know where did the cdh put the configuration file on the local file system.  </p>
  
  <p>for example, I want to find the core-site.xml, but where is it?</p>