title: transparent_hugepage/defrag warning in mongodb
body: <p>I get a warning, when enter mongo shell</p>
  
  <pre><code>** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.
  **        We suggest setting it to 'never'
  </code></pre>
  
  <p>even I've appended the following option to the kernel command line in grub.conf:</p>
  
  <pre><code>transparent_hugepage=never
  </code></pre>
  
  <p>Checking</p>
  
  <pre><code>$ cat /sys/kernel/mm/redhat_transparent_hugepage/enabled
  always [never]
  $ cat /sys/kernel/mm/redhat_transparent_hugepage/defrag
  [always] never
  </code></pre>
  
  <p>And yes, I reboot the machine after changing GRUB options and restart mongod service.</p>
  
  <p>GRUB version</p>
  
  <pre><code>$ grub-install -v
  grub-install (GNU GRUB 0.97)
  </code></pre>
  
  <p>CentOS version</p>
  
  <pre><code>$ cat /etc/redhat-release
  CentOS release 6.4 (Final)
  </code></pre>