Managing Kubernetes Storage with Persistent Volumes

Why Persistent Storage?

Containers are ephemeral — when a Pod restarts, its filesystem resets. Persistent Volumes (PVs) and Persistent Volume Claims (PVCs) let your applications on a Breeze store data that survives Pod restarts and rescheduling.

Key Concepts

• PersistentVolume (PV) — a piece of storage provisioned in the cluster
• PersistentVolumeClaim (PVC) — a request for storage by a Pod
• StorageClass — defines how storage is dynamically provisioned

Check Available Storage Classes

kubectl get storageclass

K3s includes a local-path StorageClass by default.

Create a PVC

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: app-data
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: local-path
  resources:
    requests:
      storage: 5Gi

kubectl apply -f pvc.yaml
kubectl get pvc

Use the PVC in a Pod

apiVersion: v1
kind: Pod
metadata:
  name: app-with-storage
spec:
  containers:
    - name: app
      image: nginx:alpine
      volumeMounts:
        - name: data
          mountPath: /usr/share/nginx/html
  volumes:
    - name: data
      persistentVolumeClaim:
        claimName: app-data

Access Modes

• ReadWriteOnce (RWO) — single node read-write
• ReadOnlyMany (ROX) — multiple nodes read-only
• ReadWriteMany (RWX) — multiple nodes read-write

Managing Volumes

kubectl get pv
kubectl describe pvc app-data
kubectl delete pvc app-data

Always set appropriate storage sizes and back up persistent data regularly on your Breeze.