Scenario

CCE allows you to use an existing file system to create a PersistentVolume (PV). After the creation is successful, create the corresponding PersistentVolumeClaim (PVC) and bind it to the PV.

Prerequisites

You have created a CCE cluster and installed the CSI plug-in (everest) in the cluster.

Notes and Constraints

• The following configuration example applies to clusters of Kubernetes 1.15 or later.
• To configure mount options, the everest add-on version must be 1.2.8 or later.
• Multiple PVs can use the same SFS file system with the following restrictions:
  • An error may occur if multiple PVCs/PVs that use the same underlying SFS file system are mounted to the same pod.
  • The persistentVolumeReclaimPolicy parameter in the PVs must be set to Retain. Otherwise, when a PV is deleted, the associated underlying SFS file system may be deleted. In this case, other PVs associated with the underlying SFS file system may be abnormal.
  • When the underlying SFS file system is repeatedly used, it is recommended that ReadWriteMany be implemented at the application layer to prevent data overwriting and loss.

Procedure

1. Log in to the SFS console, create a file system, and record the file system ID, shared path, and capacity.
2. Use kubectl to connect to the cluster. For details, see Connecting to a Cluster Using kubectl.
3. Create two YAML files for creating the PV and PVC. Assume that the file names are pv-sfs-example.yaml and pvc-sfs-example.yaml.

   touch pv-sfs-example.yaml pvc-sfs-example.yaml

   • vi pv-sfs-example.yaml
     Example YAML file for the PV:

     apiVersion: v1
     kind: PersistentVolume
     metadata:
       name: pv-sfs-example
       annotations:
         pv.kubernetes.io/provisioned-by: everest-csi-provisioner
     spec:
       mountOptions:
       - hard
       - timeo=600
       - nolock
       accessModes:
       - ReadWriteMany
       capacity:
         storage: 10Gi
       claimRef:
         apiVersion: v1
         kind: PersistentVolumeClaim
         name: pvc-sfs-example
         namespace: default
       csi:
         driver: nas.csi.everest.io
         fsType: nfs
         volumeAttributes:
           everest.io/share-export-location: sfs-nas01.cn-north-4.myhuaweicloud.com:/share-436304e8
           storage.kubernetes.io/csiProvisionerIdentity: everest-csi-provisioner
         volumeHandle: 682f00bb-ace0-41d8-9b3e-913c9aa6b695
       persistentVolumeReclaimPolicy: Delete
       storageClassName: csi-nas

     Table 1 Key parameters

     Parameter	Description
     driver	Storage driver used to mount the volume. Set the driver to nas.csi.everest.io for the file system.
     everest.io/share-export-location	Shared path of the file system. On the management console, choose Service List > Storage > Scalable File Service. You can obtain the shared path of the file system from the Mount Address column, as shown in Figure 1.
     volumeHandle	File system ID. On the management console, choose Service List > Storage > Scalable File Service. In the SFS file system list, click the name of the target file system and copy the content following ID on the page displayed.
     persistentVolumeReclaimPolicy	The Delete and Retain policies are supported. Delete: When a PVC is deleted, both the PV and the file system are deleted. Retain: When a PVC is deleted, the PV and underlying storage resources are not deleted. Instead, you must manually delete these resources. After that, the PV is in the Released state and cannot be bound to the PVC again. If high data security is required, you are advised to select Retain to prevent data from being deleted by mistake.
     storage	File system size.
     storageClassName	Name of the Kubernetes storage class. Set this field to csi-nas.
     spec.mountOptions	Mount options. If not specified, the following configurations are used by default. For details, see SFS Volume Mount Options. To configure mount options, the everest add-on version must be 1.2.8 or later. mountOptions: - vers=3 - timeo=600 - nolock - hard
     spec.claimRef.apiVersion	The value is fixed at v1.
     spec.claimRef.kind	The value is fixed at PersistentVolumeClaim.
     spec.claimRef.name	PVC name. The value is the same as the name of the PVC created in the next step.
     spec.claimRef.namespace	Namespace of the PVC. The value is the same as the namespace of the PVC created in the next step.

   • vi pvc-sfs-example.yaml
     Example YAML file for the PVC:

     apiVersion: v1
     kind: PersistentVolumeClaim
     metadata:
       annotations:
         volume.beta.kubernetes.io/storage-provisioner: everest-csi-provisioner
       name: pvc-sfs-example
       namespace: default
     spec:
       accessModes:
       - ReadWriteMany
       resources:
         requests:
           storage: 10Gi
       storageClassName: csi-nas
       volumeName: pv-sfs-example

     Table 2 Key parameters

     Parameter	Description
     storageClassName	Set this field to csi-nas. The value must be the same as that of the existing PV.
     storage	Storage capacity, in the unit of Gi. The value must be the same as the storage size of the existing PV.
     volumeName	Name of the PV.

   Figure 1 SFS - file system sharing paths
   
   

   The VPC to which the file system belongs must be the same as the VPC of the ECS VM to which the workload is planned.

4. Create a PV.

   kubectl create -f pv-sfs-example.yaml

5. Create a PVC.

   kubectl create -f pvc-sfs-example.yaml