The Retain reclaim policy enforces manual reclamation of the resource. When the PersistentVolumeClaim is deleted, the PersistentVolume still exists, and the volume is considered released. But it is not yet available for other claims because the previous claimant’s data remains on the volume. In our case, that data is Jenkins state. If we’d like this PersistentVolume to become available, we’d need to delete all the data on the EBS volume.
Since we are running the cluster in AWS, it is easier to delete than to recycle resources, so we’ll remove the released PersistentVolume instead of trying to clean everything we generated inside the EBS. Actually, we’ll remove all the volumes since we are about to explore how we can accomplish the same effects dynamically.