<p>what exactly is the link between these two? how can i specify that PersistentVolumeClaim must use specific PersistentVolume? it seems to be sharing files between all PersistentVolumeClaims</p>

<p>Yes, this sharing as you stated it, is the case and you could say that this is at least very troubling if you want specific volumes for a given purpose. It is beneficial if you have random usable volumes, which is often not the case.</p>

<blockquote>
  <p>Scenario: Create a NFS volume for 1 database &amp; a second volume for a second database. The database have to be retained between restarts of the pods/complete system reboots and have to be mounted again without issues later on.</p>
</blockquote>

<p>To solve this scenario (within the constraints of Kubernetes) there are several possible solution paths:</p>

<ul>
<li><p>Use the namespace as a solution to be able to prevent cross use of the volumes, resulting then in namespace issues since containers have to talk over the external (or flat) network to communicate with each other when crossing namespaces. </p></li>
<li><p>Another possible solution to solve this scenario is create the mount points using  OS mounts and using the then present local volume. This will work, but requires maintenance of the OS template, something which we were trying to prevent using Kubernetes.</p></li>
<li><p>A third possible solutions is to have the NFS mount executed from within your container, thus avoiding the persistent volume approach completely, see <a href="https://stackoverflow.com/questions/33552277/how-do-you-mount-an-external-nfs-share-in-kubernetes">How do you mount an external nfs share in Kubernetes?</a> for this</p></li>
</ul>
