title: how do I get my ubuntu VM to auto adjust the screen resolution to fit my macbook pro or an external monitor?
body: <p>I'm running an ubuntu guest on a mac osx host using virtual box.  I'm trying to get the screen resolution to auto adjust to both my macbook pro as well as an external (2nd) monitor.  </p>
  
  <p>The tutorials available on line have me using the CLI to add resolutions like</p>
  
  <pre><code>xrandr --addmode 1440x900
  </code></pre>
  
  <p>I've already tried:</p>
  
  <pre><code>xrandry --newmode "1440x900_60.00"  106.50  1440 1528 1672 1904  900 903 909 934 -hsync +vsync
  </code></pre>
  
  <p>so, when I type 'xrandr" this is the output:</p>
  
  <pre><code>Screen 0: minimum 64 x 64, current 1024 x 768, maximum 32000 x 32000
  VBOX0 connected 1024x768+0+0 0mm x 0mm
  1024x768       60.0*+
  800x600        60.0  
  640x480        60.0  
  </code></pre>
  
  <p>So, how do I get my ubuntu VM to auto adjust the screen resolution to fit my macbook pro or an external monitor?</p>