title: Adding custom settings into boot2docker profile
body: <p>I'm using Windows machine and running Docker by Docker Toolbox. To run Elasticsearch 5.0, we have to increase the Docker host (boot2docker) virtual memory.</p>
  
  <pre><code>docker-machine ssh default
  sudo vi /var/lib/boot2docker/profile
  # Add this line into /var/lib/boot2docker/profile
  sysctl -w vm.max_map_count=262144
  # Now exit and check 
  exit
  docker-machine restart default
  </code></pre>
  
  <p>However, after restarting my Windows machine (docker-machine) and starting the the docker-machine, docker-machine resets the file <code>/var/lib/boot2docker/profile</code>.</p>
  
  <p>How to keep this value persistent? I tried to put some options into the <code>docker-machine create</code> command via <code>--engine-env</code> and <code>--engine-opt</code> but have no luck.</p>