title: k8s pod log for "/var/log/maillog" is big to disabled it's machine
body: <p>I created pod on k8s cluster, and found pod is killed and it's Linux mahcine is failed to ssh login.
  when I restart the k8s node, I found the nodes home path is used for 90%. And I found the pod's log for <code>/val/log/maillog</code> is used 3T,why?</p>
  
  <pre><code>pwd
  
  /home/docker/runtime/overlay/c5b8d2bd508ab41057d151aebc55cee707a44a704cbddba268ec929ff7e80542/upper/var/log
  </code></pre>
  
  <pre><code>du -sh *
  
  2.9T    maillog 
  4.0K    messages
  </code></pre>
  
  <pre><code>tail -n 2 maillog
  
  &gt; Apr 10 23:19:15 visbox1 04-10T23:19:15.417908+08:00 visbox1
  &gt; 04-10T23:19:15.417846+08:00 visbox1 04-10T23:19:15.417789+08:00
  &gt; visbox1 04-10T23:19:15.417734+08:00 visbox1
  &gt; 04-10T23:19:15.417675+08:00 visbox1 04-10T23:19:15.417582+08:00
  &gt; visbox1 04-10T23:19:15.417526+08:00 visbox1
  &gt; 04-10T23:19:15.417467+08:00 visbox1 04-10T23:19:15.417409+08:00
  &gt; visbox1 04-10T23:19:15.417355+08:00 visbox1
  &gt; 04-10T23:19:15.417300+08:00 visbox1 04-10T23:19:15.417243+08:00
  &gt; visbox1 04-10T23:19:15.417149+08:00 visbox1
  &gt; 04-10T23:19:15.417091+08:00 visbox1 04-10T23:19:15.417035+08:00
  &gt; visbox1 04-10T23:19:15.416978+08:00 visbox1
  &gt; 04-10T23:19:15.416920+08:00 visbox1 04-10T23:19:15.416858+08:00
  &gt; visbox1 04-10T23:19:15.416796+08:00 visbox1
  &gt; 04-10T23:19:15.416739+08:00 visbox1 04-10T23:19:15.416684+08:00
  &gt; visbox1 04-10T23:19:15.416627+08:00 visbox1
  &gt; 04-10T23:19:15.416574+08:00 visbox1 04-10T23:19:15.416507+08:00
  
  </code></pre>
  
  <p>the visbox1 is the name of pod</p>