title: Docker error: exit status 255
body: <p>I'm new to docker.I can't restart virtual machine in docker.I don't know what 'exit status 255' means, while running <code>docker-machine restart vdocker</code> it shows </p>
  
  <pre><code>$docker-machine restart vdocker
  Restarting "vdocker"...
  Starting "vdocker"...
  &lt;vdocker&gt; Check network to re-create if needed...
  &lt;vdocker&gt; Waiting for an IP...
  Too many retries waiting for SSH to be available. Last error:Maximum number of retries &lt;60&gt; exceeded
  </code></pre>
  
  <p>running <code>docker-machine ls</code> shows </p>
  
  <pre><code>$docker-machine ls
  NAME     ACTIVE  DRIVER      STATE    URL                       SWARM        DOCKER    ERRORS
  default    *     virtualbox  Running  tcp://192.168.99.100:2376              v1.11.2
  vdocker    -     virtualbox  Running                                         Unknown   Somthing went wrong running an SSH command!
  command : ip addr show
  err     : exit status 255
  output  :  
  </code></pre>
  
  <p>but default machine is working well.</p>
  
  <p>Please let me know if you need any more info or clarity on the problem.</p>