title: how to upgrade CentOS 5.11 to 6.x
body: <p>I have tried executing yum update command but it only took me from 5.11 to 6.x.  I need the server to be running CentOS 6.x for nagiosxi.  </p>
  
  <pre><code>[root@nagiosxi network-scripts]# uname -a
  Linux nagiosxi.inl.gov 2.6.18-371.8.1.el5 #1 SMP Thu Apr 24 18:23:07 EDT 2014 i686 i686 i386 GNU/Linux
  </code></pre>