title: linux file system permission issue
body: <p>I'm deploying nutch.  At first I just left the index file under <code>/root/nutch1.0</code>.  This works fine when run from command line.  However, when I search from web, it always returns <code>0 hit</code>.</p>
  
  <p>I finally found the reason:  It's because the index file is located under <code>/root</code> that causes the failure to open the file. Things returned to normal when I move the index file to another directory.</p>
  
  <p>But my question is:</p>
  
  <p>I didn't change the permissions of the index file (just <code>cp</code> xxx another-directory).  Why did the access rights change?</p>
  
  <pre><code>drwxr-x--- 12 root root    4096 Jun  1 14:49 root
  drwxr-xr-x 14 root root    4096 Nov 16  2007 usr
  </code></pre>
  
  <p>I put files under <code>/usr</code> and it worked.</p>