title: How to disable a Linux entropy pool source
body: <p>How do I disable entropy sources?</p>
  
  <p>Here's a little background on what I'm trying to do. I'm building a little RNG device that talks to my PC via USB. I want it to be the only source of entropy used. I'll use <code>rngd</code> to add my device as a source of entropy. </p>