title: pivot_root device or resource busy
body: <p>Produces the following command on Ubuntu 64bit on VMWare:</p>
  
  <pre><code>mount /dev/sda1 /newroot
  cd /newroot
  mkdir old-root
  pivot_root . old-root
  </code></pre>
  
  <p>I get an error that I do not understand</p>
  
  <pre><code>pivot_root: device or resource busy
  </code></pre>
  
  <p>Any ideas?</p>