title: GC collection of Docker Registry
body: <p>Since v2.4.0 a garbage collector command is included within the registry binary. I read about how it works in the <a href="https://docs.docker.com/registry/garbage-collection/" rel="nofollow">official documentation</a>.</p>
  
  <p>To use the garbage-collection:</p>
  
  <pre><code>bin/registry garbage-collect [--dry-run] /path/to/config.yml
  </code></pre>
  
  <p>I see the config in <code>/etc/docker/registry/config.yml</code>
  When I just perform a dry-run I see a lot of blobs marked and at the end the blobs which would have been deleted without dry-run. 
  But I don't see how I can easily link this blobs to images?
  Which images will be deleted and am I able to tell which image should be deleted or do I need to use another command and after that I have to run the gc?)</p>
  
  <p>Can someone maybe provide an example in which case an image/blob will be deleted? Thanks</p>