静态 pv 和动态 pv

pv 分静态和动态两种

静态：
需要我们自己去手动创建，业务少的情况下可以用手动创建。

动态：
根据 yaml 文件里面的参数自动创建合适的 pv，业务量大或者静态 pv 无法满足需求的时候需要动态创建 pv。

pod 绑定 pvc，pvc 绑定 pv。（pod 消耗的是节点，pvc 消耗的是 pv 的资源。）

一、静态绑定 pv
1、创建 pv.yaml 文件并部署

cat >> pv.yaml >> EOF

apiVersion: v1
kind: PersistentVolume
metadata:
  name:  pv-nfs
spec:
  capacity: 
    storage: 1Gi
  accessModes: ["ReadWriteOnce"]
  persistentVolumeReclaimPolicy: Recycle
  nfs:
    path: /data/k8s
    server: 10.151.30.57

2、创建 pvc.yaml 文件并部署

cat >> pvc.yaml << EOF

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: pvc-nfs
spec:
  accessModes: ["ReadWriteOnce"]
  resources:
    requests:
      storage: 1Gi

3、查看之前创建的 pv

[root@master1 ~]# kubectl get pv
NAME      CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM               STORAGECLASS   REASON    AGE   
pv-nfs       1Gi        RWO            Recycle          Available

可以看到 pv 状态是可用的，还没有 pvc 绑定。

4、部署 pvc.yaml

kubectl get pvc
NAME        STATUS    VOLUME    CAPACITY   ACCESS MODES   STORAGECLASS   AGE
pvc-nfs     Bound     pv-nfs    1Gi        RWO                           12s



再查看 pv 状态
kubectl get pv
NAME      CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS    CLAIM               STORAGECLASS   REASON    AGE
pv-nfs    1Gi        RWO            Recycle          Bound     default/pvc-nfs

看到 PV 是 Bound 状态了，说明已经绑定成功了。

二、动态绑定 pv

1、部署后端 NFS 或者其他存储并设置默认 storageclass 略，前面有过讲解。这里用 NFS 作为 K8S 后端存储
https://www.cnblogs.com/lfl17718347843/p/14131062.html

2、创建测试文件
cat >> statefulset-nfs.yaml << EOF

apiVersion: v1
kind: Service
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  ports:
  - port: 80
    name: web
  clusterIP: None
  selector:
    app: nginx
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: nfs-web
spec:
  serviceName: "nginx"
  replicas: 3
  selector:
    matchLabels:
      app: nfs-web # has to match .spec.template.metadata.labels
  template:
    metadata:
      labels:
        app: nfs-web
    spec:
      terminationGracePeriodSeconds: 10
      containers:
      - name: nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80
          name: web
        volumeMounts:
        - name: www
          mountPath: /usr/share/nginx/html
  volumeClaimTemplates:
  - metadata:
      name: www
      annotations:
        volume.beta.kubernetes.io/storage-class: managed-nfs-storage    # 默认后端存储
    spec:
      accessModes: ["ReadWriteOnce"]
      resources:
        requests:
          storage: 1Gi

3、部署并查看是否自动创建动态 pv

[root@master1 ~]# kubectl get pods
NAME                                      READY   STATUS    RESTARTS   AGE
nfs-web-0                                 1/1     Running   0          44m
nfs-web-1                                 1/1     Running   0          44m
nfs-web-2                                 1/1     Running   0          43m


[root@master1 ~]# kubectl get pv
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                                                             STORAGECLASS          REASON   AGE
pvc-23e3cdb2-a365-43ff-8936-d0e3df30ffac   1Gi        RWO            Delete           Bound    default/www-nfs-web-1                                             managed-nfs-storage            45m
pvc-2c34b87d-4f09-4063-aea9-9ae1e7567194   1Gi        RWO            Delete           Bound    default/www-nfs-web-2                                             managed-nfs-storage            45m
pvc-7cdcdc4c-e9d2-4848-b434-9caf7e72db5a   1Gi        RWO            Delete           Bound    default/www-nfs-web-0                                             managed-nfs-storage            46m


[root@master1 ~]# ll /data/volumes/v1
total 0
drwxrwxrwx 2 root root  6 Feb 13 14:30 default-www-nfs-web-0-pvc-7cdcdc4c-e9d2-4848-b434-9caf7e72db5a
drwxrwxrwx 2 root root  6 Feb 13 14:31 default-www-nfs-web-1-pvc-23e3cdb2-a365-43ff-8936-d0e3df30ffac
drwxrwxrwx 2 root root  6 Feb 13 14:31 default-www-nfs-web-2-pvc-2c34b87d-4f09-4063-aea9-9ae1e7567194