title: Linux file exception:Device or resource busy
body: <p>An simplified load balance cluster scene: 2 CentOS7 with GlusterFS to share some configuration files(Replicate type),and mount the Gluster filesystem to each node(eg. /mnt/gluster/); then I used <strong>mount --bind</strong> command to link the *.conf file from glusterfs mount point to my application dir(eg. /my/app/).</p>
  
  <p>I modify the conf file in /my/app/ dir, it could spread the modification correctly to each node in the cluster. But once I modified files in such as <code>/mnt/gluster/example.conf</code>, the mount point of this file(like <code>/my/app/example.conf</code>) would turn to unreachable status. Looks like:</p>
  
  <pre><code>[root@gluster1 mount]#ll
    ls: cannot access 1: No such file or directory
    total 0
    -????????? ? ? ? ?            ? example.conf
    [root@gluster1 mount]#mv example.conf example.bak
    mv: cannot move ‘example.conf’ to ‘example.bak’: Device or resource busy
  </code></pre>
  
  <p><strong>My question:</strong></p>
  
  <ol>
  <li><p>If the original file can be modified when we using 'mount --bind' to it?</p></li>
  <li><p>Why the file turn to a ghost file? (<em>No such file or directory</em> or <em>Device or resource busy</em>).</p></li>
  </ol>