Use a disk as a dynamic volume

Connect to your ACS cluster. For more information, see Obtain the kubeconfig file of a cluster and use kubectl to connect to the cluster and Use kubectl on Cloud Shell to manage ACS clusters.

Save the following YAML content as disk-sc.yaml. Modify the parameters as described in the table below.

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: alicloud-disk-essd
provisioner: diskplugin.csi.alibabacloud.com
parameters:
  type: cloud_essd
  fstype: ext4
  performanceLevel: PL1
reclaimPolicy: Delete
volumeBindingMode: WaitForFirstConsumer
allowVolumeExpansion: true

The following table describes the parameters.

Create the StorageClass.

kubectl create -f disk-sc.yaml

View the StorageClass.

kubectl get sc

Expected output:

NAME                             PROVISIONER                       RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
alicloud-disk-essd               diskplugin.csi.alibabacloud.com   Delete          WaitForFirstConsumer   true                   78s
alicloud-disk-topology-alltype   diskplugin.csi.alibabacloud.com   Delete          WaitForFirstConsumer   true                   23d
......

Save the following YAML content as disk-pvc.yaml.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: disk-pvc
spec:
  accessModes:
  - ReadWriteOncePod
  volumeMode: Filesystem
  resources:
    requests:
      storage: 20Gi
  storageClassName: alicloud-disk-essd

The following table describes the parameters.

Create the PVC.

kubectl create -f disk-pvc.yaml

View the PVC.

kubectl get pvc

The expected output shows that the PVC is not yet bound to a PV because volumeBindingMode is set to WaitForFirstConsumer:

NAME       STATUS    VOLUME   CAPACITY   ACCESS MODES   STORAGECLASS         VOLUMEATTRIBUTESCLASS   AGE
disk-pvc   Pending                                      alicloud-disk-essd   <unset>                 7s

Save the following YAML content as disk-test.yaml.

The following YAML creates a StatefulSet with one Pod. The Pod requests storage through a PVC named disk-pvc and mounts the volume at /data.

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: disk-test
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: registry.cn-hangzhou.aliyuncs.com/acs-sample/nginx:latest
        ports:
        - containerPort: 80
        volumeMounts:
        - name: pvc-disk
          mountPath: /data
      volumes:
        - name: pvc-disk
          persistentVolumeClaim:
            claimName: disk-pvc

Create the StatefulSet and mount the disk.

kubectl create -f disk-test.yaml

Check the deployment status of the Pod in the StatefulSet.

kubectl get pod | grep disk-test

The expected output shows one Pod because the replica count of the StatefulSet is 1.

disk-test-0   1/1     Running   0          52s

View the PVC.

kubectl get pvc

The expected output shows that the PVC is now bound to the automatically created PV.

NAME       STATUS   VOLUME                   CAPACITY   ACCESS MODES   STORAGECLASS         VOLUMEATTRIBUTESCLASS   AGE
disk-pvc   Bound    d-uf698s3h14isyj6b****   20Gi       RWOP           alicloud-disk-essd   <unset>                 111s

Check the mount path to confirm that the disk is mounted.

kubectl exec disk-test-0 -- df | grep data

Expected output:

/dev/vdb        20466256      24  20449848   1% /data

Log on to the ACS console.

On the Clusters, click the name of the cluster to go to the cluster management page.

In the left-side navigation pane of the cluster management page, choose Volumes > StorageClasses.

Create a StorageClass.

1. On the StorageClasses page, click Create.

2. In the dialog box that appears, configure the parameters and then click Create.

   Parameter	Description	Example
   Name	The name of the StorageClass. Follow the format requirements on the screen.	alicloud-disk-essd
   PV Type	Select Disk.	Disk
   Parameter	The default parameter is type, which specifies the disk type. Valid values: cloud_essd_entry: ESSD Entry disk cloud_auto: ESSD AutoPL disk cloud_essd (default): ESSD cloud_ssd: standard SSD cloud_efficiency: ultra disk You can combine these types. For example: type: cloud_efficiency, cloud_ssd, cloud_essd. The system tries each type in order until a disk is created successfully. Note You can choose a disk type based on your billing and performance needs. For more information, see Block Storage Pricing and Block storage performance. You can add the following parameters: fstype The file system type. Default: ext4. Valid values: ext3, ext4, and xfs. performanceLevel The ESSD performance level. Default: PL1. Valid values: PL0, PL1, PL2, and PL3. For more information, see ESSDs.	type: cloud_essd
   Reclaim Policy	The reclaim policy for the disk. Only Delete is supported, meaning the PV and underlying disk are deleted when the persistent volume claim (PVC) is deleted.	Delete
   Binding Mode	The volume binding mode. We recommend WaitForFirstConsumer for multi-zone clusters. WaitForFirstConsumer: Delays volume binding. The Pod is scheduled first, then the disk is created in the Pod's availability zone. Immediate: Creates the disk before the Pod is scheduled. Important If you use ACS computing power in an ACK cluster and the ACS Pod needs to mount a disk, use nodeSelector or ResourcePolicy to schedule the Pod to a virtual node. If you schedule the Pod by adding the Pod label (alibabacloud.com/acs: "true"), StorageClasses with the WaitForFirstConsumer type are not supported.	WaitForFirstConsumer

In the left-side navigation pane of the cluster management page, choose Volumes > Persistent Volume Claims.

On the Persistent Volume Claims page, click Create.

In the dialog box that appears, configure the parameters and then click Create.

After the PVC is created, it appears on the Persistent Volume Claims page. Because the binding mode in the StorageClass is WaitForFirstConsumer, the PVC is not yet bound to a PV and its status is Pending.

In the left-side navigation pane of the cluster management page, choose Workloads > StatefulSets.

On the StatefulSets page, click Create from Image.

Configure the parameters for the StatefulSet, and then click Create.

Set the following parameters and keep the defaults for the rest. For more information, see Create a StatefulSet workload.

Check the application deployment status.

1. On the StatefulSets page, click the name of the application.

2. On the Pods tab, confirm that the Pod is running properly (its status is Running).

Check the volume and the claim.

• On the Persistent Volumes page, you will find an automatically created PV. The name of the PV corresponds to the disk ID.

• On the Persistent Volume Claims page, the PVC is now bound to the PV, and its status is Bound.