title: Why do I need a PersistentVolume, if I have a PersistentVolumeClaim?
body: <p>Every while I see these scenarios where people create a PV and a PVC to bind to it, and I wonder what's the need?</p>
  
  <p>So, one can create a PVC with <code>volumeName: my-volume</code>, and have it bounded to an existing PV. Or create the PV later, in which case PVC wouldn't be bounded to any PV, and it would stay in Pending state forever, until the PV gets created with the given name.</p>
  
  <p>Now, my question is why? Why do we need to create a PVC and then the PV? There are two scenarios I see it half useful:</p>
  
  <ol>
  <li>When you don't want the PVC to create a PV with random name, and you
  want to control the name of the PV, but even in that scenario, just
  create the PV with the name you want. Why to create the PVC?</li>
  <li>If you delete the PV with a PVC bound to
  it with <code>persistentVolumeReclaimPolicy: Retain</code>, then the PV
  wouldn't get deleted, but would stay in <code>Terminating</code> state. Still,
  I am not sure if you can re-use this PV with <code>Terminating</code> state.</li>
  </ol>
  
  <p><a href="https://docs.openshift.com/container-platform/3.3/dev_guide/persistent_volumes.html" rel="nofollow noreferrer">Openshift</a> explains this as <strong>Binding</strong> and <strong>Pre-binding</strong>. Still doesn't give any details of the use cases.</p>
  
  <p><strong>EDIT</strong></p>
  
  <p>I know what is a PV and a PVC, and when to use them, so no need to explain the basics. I want to know the use case of creating both at the same time.</p>