title: Clearing the cache in ezPublish 5.1 forces conversion of all images
body: <p>I've "inherited" an ezPublish server running 5.1, with 4.7 legacy as well.  Whenever an admin goes to Setup and clears the caches, it regenerates <strong>all</strong> of the images (thousands of them) in a variety of sizes -- this takes hours, during which the server load is so high, it's down for all practical purposes.</p>
  
  <p>My questions are:</p>
  
  <ol>
  <li>What's causing this? It can't be normal behavior</li>
  <li>Is there a way to specify that 'convert' run as a low-priority?</li>
  </ol>
  
  <p>Thank you in advance.</p>