kubernetes 持久化卷和持久化卷声明超出存储

Question

By following kubernetes guide i have created a pv, pvc and pod. i have claimed only 10Mi of out of 20Mi pv. I have copied 23Mi that is more than my pv. But my pod is still running. Can any one explain ?

pv-volume.yaml

kind: PersistentVolume
apiVersion: v1
metadata:
  name: task-pv-volume
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 20Mi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/mnt/data"

pv-claim.yaml

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: task-pv-claim
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 10Mi

pv-pod.yaml

kind: Pod
apiVersion: v1
metadata:
  name: task-pv-pod
spec:
  volumes:
    - name: task-pv-storage
      persistentVolumeClaim:
       claimName: task-pv-claim
  containers:
    - name: task-pv-container
      image: nginx
      ports:
        - containerPort: 80
          name: "http-server"
      volumeMounts:
        - mountPath: "/usr/share/nginx/html"
          name: task-pv-storage

Answer 1

Probably you can copy as much data into shared storage /mnt/data (on your active node) using any of applied POD's storages , /usr/share/nginx/html , shared between node and pods till your node will stop responding.

In case you need to test this scenario in more real conditions could you please consider create NFS persistent storage using GlusterFS , nfs-utils , or mount a raw partition file made with dd .

In Minikube nodes are using ephemeral-storages. Detailed information about node/pod resources you can find here:

https://kubernetes.io/docs/tasks/administer-cluster/reserve-compute-resources/#node-allocatable
Hope this help.