title: "IOError: [Errno 71] Protocol error" when reading a file with python in a virtualbox debian machine
body: <p>I try to open and read a file in Python 2.7.3 which is running in a virtual machine:</p>
  
  <p>Host: Ubuntu 14.04 LTS</p>
  
  <p>Guest: Debian Wheezy 7.5</p>
  
  <p>VM-Software: VirtualBox V4.3.30</p>
  
  <p>In the Python console inside the VM, I enter the following:</p>
  
  <pre><code>&gt;&gt;&gt; f = open("Testing/results.txt", "w+")
  &gt;&gt;&gt; f.read()
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  IOError: [Errno 71] Protocol error
  </code></pre>
  
  <p>The file exists and is located in a shared folder. If I try to do the same on a file which is located on the file system of the VM, it works fine. Also opening the file with mode "r+" or "a+", it works but it doesn't get truncated. Truncating the file manually after opening in read mode is working and currently, I use that as a workaround. But maybe anybody here knows, why this error occurs?</p>