title: what is the workaround for the kernel too old error in docker on centos
body: <p>I just started dockering and here hits my very first docker question.</p>
  <p>I am using <code>CentOS release 6.6 (Final)</code>.</p>
  <p>I need to build a docker image for JupyterHub, here is the JupyterHub image: <a href="https://hub.docker.com/r/jupyterhub/jupyterhub/" rel="nofollow noreferrer">https://hub.docker.com/r/jupyterhub/jupyterhub/</a>, what I did is:</p>
  <pre><code>docker pull jupyterhub/jupyterhub
  </code></pre>
  <p>And then I ran:</p>
  <pre><code>sudo docker images
  </code></pre>
  <p>, I see the following:</p>
  <pre><code>REPOSITORY              TAG                 IMAGE ID            CREATED             VIRTUAL SIZE
  jupyterhub/jupyterhub   latest              3726912b8cfc        5 months ago        811.5 MB
  &lt;none&gt;                  &lt;none&gt;              7cdb3c49d61f        2 years ago         4.766 GB
  </code></pre>
  <p>What is the huge <strong>none</strong> repo that comes with an image id?
  When I ran:</p>
  <p>sudo docker run --name test 3726912b8cfc
  I received:</p>
  <blockquote>
  <p>FATAL: kernel too old</p>
  </blockquote>
  <p>What does it mean? and how to work around with it?</p>