When a PersistentVolume is used as a resource within a cluster through the
creation of a PersistentVolumeClaim it is important to know that the underlying
physical volume assigned to the claim will persist if the cluster is removed.
Note
The persistence of the underlying volume is not affected by the setting
of the StorageClass Reclaim Policy in the scenario where the cluster is
deleted before removing resources.
If the PersistentVolumeClaim resource was intentionally released prior to the
cluster being terminated however, the usual retention policy for that
storage class will apply.
The policy Retain is the default provided, and this allows for manual deletion of the underlying resource. This prevents accidental removal, and permits re-attachment to another Kubernetes cluster.
For some workloads, it will be preferable to use the Delete reclaim policy which
will remove both the automatically created PersistentVolume and the underlying
Cinder volume when the PersistentVolumeClaim is deleted.
Refer to the Kubernetes documentation on Persistent Volume Reclaiming for more details.