title: how to clear cache memory inside docker container
body: <p>I have a docker swarm CE setup in EC2.
  I have two nodes. 1 manager and 1 worker.
  The host instance type is Alpine Linux.</p>
  
  <p>In the Manager host the Memory usage is:</p>
  
  <pre><code>~ $ free -m
                      total       used       free     shared    buffers     cached
  Mem:                 7972       4996       2975        715        178       2857
  -/+ buffers/cache:   1960       6011
  Swap:                 0          0          0
  </code></pre>
  
  <p>~ $ </p>
  
  <p>Now when i login the container,</p>
  
  <pre><code>~ $ docker exec -it c7cc255aca1f /bin/bash
   [root@c7cc255aca1f /]# 
  
  And see the memory utilization:
  
  [root@c7cc255aca1f /]# free -m
                total        used        free      shared  buff/cache   available
  Mem:           7972        1654        2970         715        3347        5269
  Swap:             0           0           0
  [root@c7cc255aca1f /]#
  </code></pre>
  
  <p>Kindly help me how to clear the buff/cache or cached ?</p>