第 32 章 Cluster recovery from persistent volumes

When you delete a namespace, all resources within that namespace—including PVCs, pods, and services—are deleted. If the reclaimPolicy for the PV resource specification is set to Retain, the PV retains its data and is not deleted. This configuration allows you to recover from namespace deletion.

apiVersion: v1
kind: PersistentVolume
# ...
spec:
  # ...
  persistentVolumeReclaimPolicy: Retain

Alternatively, PVs can inherit the reclaim policy from an associated storage class. Storage classes are used for dynamic volume allocation.

By configuring the reclaimPolicy property for the storage class, PVs created with this class use the specified reclaim policy. The storage class is assigned to the PV using the storageClassName property.

apiVersion: v1
kind: StorageClass
metadata:
  name: gp2-retain
parameters:
  # ...
# ...
reclaimPolicy: Retain

apiVersion: v1
kind: PersistentVolume
# ...
spec:
  # ...
  storageClassName: gp2-retain

If you lose the entire OpenShift cluster, all resources—including PVs, PVCs, and namespaces—are lost. However, it’s possible to recover if the physical storage backing the PVs remains intact.

To recover, you need to set up a new OpenShift cluster and manually reconfigure the PVs to use the existing storage.