在kube-node1上新建本地目录/mnt/data作为PV,并在目录中新建文件index.hml
[root@kube-node1 ~]#mkdir /mnt/data
[root@kube-node1 ~]#echo 'Hello from Kubernetes storage' > /mnt/data/index.html
新建pv.yaml定义pv task-pv-volume,其中容量为10Gi，访问模式为单个node上读写挂载，storageClassName为manual
kind: PersistentVolume
apiVersion: v1
metadata:
name: task-pv-volume
labels:
type: local
spec:
storageClassName: manual
capacity:
storage: 10Gi
accessModes:
- ReadWriteOnce
hostPath:
path: "/mnt/data"
创建pv
[root@kube-node1 ~]# kubectl apply -f pv.yaml
persistentvolume/task-pv-volume created
查看pv，可以看到yaml中定义的参数及reclaim策略为Retain
[root@kube-node1 ~]# kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
task-pv-volume 10Gi RWO Retain Available manual 118s
新建pvc.yaml定义pvc task-pv-claim，读写模式、storageClassName与PV一致，requests小于PV
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: task-pv-claim
spec:
storageClassName: manual
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 3Gi
创建PVC资源
[root@kube-node1 ~]# kubectl apply -f pvc.yaml
persistentvolumeclaim/task-pv-claim created
查看PVC,可以看到PVC的容量为实际匹配到的PV的容量。PVC会匹配大于等于“pvc请求资源”中并最接近请求资源的那个PV
[root@kube-node1 ~]# kubectl get pvc
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
task-pv-claim Bound task-pv-volume 10Gi RWO manual 35s
新建pod定义文件pv-pvc-pod.yaml挂载PVC
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
创建Pod task-pv-pod
[root@kube-node1 ~]# kubectl apply -f pv-pvc-pod.yaml
pod/task-pv-pod created
查看Pod task-pv-pod
[root@kube-node1 ~]# kubectl get pods task-pv-pod
NAME READY STATUS RESTARTS AGE
task-pv-pod 1/1 Running 0 24s
进入Pod查看PV挂载目录，并没有发现文件index.html
[root@kube-node1 ~]# kubectl exec -it task-pv-pod -- /bin/bash
root@task-pv-pod:/# cd /usr/share/nginx/html
root@task-pv-pod:/usr/share/nginx/html# ls
检查发现pod调度到了kube-node2，kube-node2上没有创建相关目录和文件
[root@kube-node1 ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE
task-pv-pod 1/1 Running 0 2m24s 10.244.1.108 kube-node2 <none>
修改pv-pvc-pod.yaml，选择在kube-node1上运行Pod，删除原有pod并重新启动Pod
kind: Pod
apiVersion: v1
metadata:
name: task-pv-pod
spec:
nodeSelector:
kubernetes.io/hostname: kube-node1
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
重新进入pod，可以看到index.html已经存在
[root@kube-node1 ~]# kubectl exec -it task-pv-pod -- /bin/sh
#
# cd /usr/share/nginx/html
# ls
index.html
# cat index.html
Hello from Kubernetes storage
#cd ..
# ls -l
total 0
drwxr-xr-x 2 root root 24 Apr 1 03:10 html
[if !supportLists]Ø [endif]存储对象的保护
如果删除正在使用的PVC，不会立即删除PVC，直到没有任何Pod使用PVC；如果删除已经绑定PVC的PV，不会立即删除PVC，直到没有任何PVC使用PV。
删除pvc task-pv-claim，可以发现删除无法完成。如果此时按Ctrl+C将无法终止，删除命令已经提交，当保护不再生效时会删除。
查看pvc和pv都可以看到 Finalizers:[kubernetes.io/pvc-protection]
由于PVC没有正常删除，删除pv同样无法完成
查看pv状态，可以发现状态变为Terminating
当pod删除后，pv和pvc都可以完成删除。
[if !supportLists]Ø [endif]PV的回收
Retained: PVC删除后，变为released，不能再次被claim，需要手动回收：删除PV及相关文件和存储上的对象
Recycled：
Deleted：需要与云存储配合
[if !supportLists]Ø [endif]访问模式
ReadWriteOnce – 单节点读写挂载
ReadOnlyMany – 多节点只读挂载
ReadWriteMany – 多节点读写挂载
注意：一个Volume一次只能使用一个访问模式装载.
[if !supportLists]Ø [endif]PV的状态
Available –空闲的，还没有被使用
Bound – volume已经绑定到claim
Released – claim已经删除，但是资源还没有回收
Failed –自动回收失败
