Using an Existing SFS Turbo File System Through a Static PV

Prerequisites

• You have created a cluster and installed the CSI add-on (everest) in the cluster.
• If you want to create a cluster using commands, use kubectl to connect to the cluster. For details, see Connecting to a Cluster Using kubectl.
• You have created an available SFS Turbo file system, and the SFS Turbo file system and the cluster are in the same VPC.

Constraints

• Multiple PVs can use the same SFS or SFS Turbo file system with the following restrictions:
  • If multiple PVCs/PVs use the same underlying SFS or SFS Turbo file system, when you attempt to mount these PVCs/PVs to the same pod, all PVCs cannot be mounted to the pod and the pod startup fails. This is because the volumeHandle values of these PVs are the same.
  • The persistentVolumeReclaimPolicy parameter in the PVs must be set to Retain. Otherwise, when a PV is deleted, the associated underlying volume may be deleted. In this case, other PVs associated with the underlying volume malfunction.
  • When the underlying volume is repeatedly used, enable isolation and protection for ReadWriteMany at the application layer to prevent data overwriting and loss.

Using an Existing SFS Turbo File System on the Console

1. Log in to the CCE console and click the cluster name to access the cluster console.
2. Statically create a PVC and PV.
   1. Choose Storage from the navigation pane, and click the PersistentVolumeClaims (PVCs) tab. Click Create PVC in the upper right corner. In the dialog box displayed, configure the PVC parameters.

      Parameter	Description
      PVC Type	In this section, select SFS Turbo.
      PVC Name	Enter the PVC name, which must be unique in the same namespace.
      Creation Method	You can create a storage volume or use an existing storage volume to statically create a PVC based on whether a PV has been created. In this example, select Create new to create a PV and PVC at the same time on the console.
      PVa	Select an existing PV volume in the cluster. Create a PV in advance. For details, see "Creating a storage volume" in Related Operations. You do not need to specify this parameter in this example.
      SFS Turbob	Click Select SFS Turbo. On the displayed page, select the SFS Turbo file system that meets your requirements and click OK.
      PV Nameb	Enter the PV name, which must be unique in the same cluster.
      Access Modeb	SFS Turbo volumes support only ReadWriteMany, indicating that a storage volume can be mounted to multiple nodes in read/write mode. For details, see Volume Access Modes.
      Reclaim Policyb	Only Retain is supported, indicating that the PV is not deleted when the PVC is deleted. For details, see PV Reclaim Policy.
      Mount Optionsb	Enter the mounting parameter key-value pairs. For details, see Configuring SFS Turbo Mount Options.

      

      a: The parameter is available when Creation Method is set to Use existing.

      b: The parameter is available when Creation Method is set to Create new.

   2. Click Create to create a PVC and a PV.

      You can choose Storage in the navigation pane and view the created PVC and PV on the PersistentVolumeClaims (PVCs) and PersistentVolumes (PVs) tab pages.

3. Create an application.
   1. In the navigation pane on the left, click Workloads. In the right pane, click the Deployments tab.
   2. Click Create Workload in the upper right corner. On the displayed page, click Data Storage in the Container Settings area and click Add Volume to select PVC.
      Mount and use storage volumes, as shown in Table 1. For details about other parameters, see Workloads.

      Table 1 Mounting a storage volume

      Parameter	Description
      PVC	Select an existing SFS Turbo volume.
      Mount Path	Enter a mount path, for example, /tmp. This parameter indicates the container path to which a data volume will be mounted. Do not mount the volume to a system directory such as / or /var/run. Otherwise, containers will be malfunctional. Mount the volume to an empty directory. If the directory is not empty, ensure that there are no files that affect container startup. Otherwise, the files will be replaced, causing container startup failures or workload creation failures. NOTICE: If a volume is mounted to a high-risk directory, use an account with minimum permissions to start the container. Otherwise, high-risk files on the host machine may be damaged.
      Subpath	Enter a subpath, for example, tmp, indicating that data in the mount path of the container will be stored in the tmp folder of the volume. A subpath is used to mount a local volume so that the same data volume is used in a single pod. If this parameter is left blank, the root path is used by default.
      Permission	Read-only: You can only read the data in the mounted volumes. Read/Write: You can modify the data volumes mounted to the path. Newly written data is not migrated if the container is migrated, which may cause data loss.

      In this example, the disk is mounted to the /data path of the container. The container data generated in this path is stored in the SFS Turbo file system.

   3. After the configuration, click Create Workload.

      After the workload is created, the data in the container mount directory will be persistently stored. Verify the storage by referring to Verifying Data Persistence and Sharing.

(kubectl) Using an Existing SFS File System

1. Use kubectl to connect to the cluster.
2. Create a PV.
   1. Create the pv-sfsturbo.yaml file.

      apiVersion: v1
      kind: PersistentVolume
      metadata:
        annotations:
          pv.kubernetes.io/provisioned-by: everest-csi-provisioner
        name: pv-sfsturbo    # PV name.
      spec:
        accessModes:
        - ReadWriteMany      # Access mode. The value must be ReadWriteMany for SFS Turbo.
        capacity:
          storage: 500Gi       # SFS Turbo volume capacity.
        csi:
          driver: sfsturbo.csi.everest.io    # Dependent storage driver for the mounting.
          fsType: nfs
          volumeHandle: <your_volume_id>   # SFS Turbo volume ID.
          volumeAttributes:
            everest.io/share-export-location: <your_location>   # Shared path of the SFS Turbo volume.
            everest.io/enterprise-project-id: <your_project_id>  # Project ID of the SFS Turbo volume.
            storage.kubernetes.io/csiProvisionerIdentity: everest-csi-provisioner
        persistentVolumeReclaimPolicy: Retain    # Reclaim policy.
        storageClassName: csi-sfsturbo          # Storage class name of the SFS Turbo file system.
        mountOptions: []                         # Mount options.

      Table 2 Key parameters

      Parameter	Mandatory	Description
      volumeHandle	Yes	SFS Turbo volume ID. How to obtain: Log in to the console, choose Service List > Storage > Scalable File Service, and select SFS Turbo. In the list, click the name of the target SFS Turbo volume. On the details page, copy the content following ID.
      everest.io/share-export-location	Yes	Shared path of the SFS Turbo volume. Log in to the console, choose Service List > Storage > Scalable File Service, and select SFS Turbo. You can obtain the shared path of the file system from the Mount Address column.
      everest.io/enterprise-project-id	No	Project ID of the SFS Turbo volume. How to obtain: On the SFS console, click SFS Turbo in the left navigation pane. Click the name of the SFS Turbo file system to interconnect. On the Basic Info tab, find and click the enterprise project to go to the console, and copy the ID.
      mountOptions	No	Mount options. If not specified, the following configurations are used by default. For details, see Configuring SFS Turbo Mount Options. mountOptions: - vers=3 - timeo=600 - nolock - hard
      persistentVolumeReclaimPolicy	Yes	A reclaim policy is supported when the cluster version is or later than 1.19.10 and the everest version is or later than 1.2.9. Only the Retain reclaim policy is supported. For details, see Verifying Data Persistence and Sharing. 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 status and cannot be bound to the PVC again.
      storage	Yes	Requested capacity in the PVC, in Gi.
      storageClassName	Yes	The storage class name of SFS Turbo volumes is csi-sfsturbo.

   2. Run the following command to create a PV:

      kubectl apply -f pv-sfsturbo.yaml

3. Create a PVC.
   1. Create the pvc-sfsturbo.yaml file.

      apiVersion: v1
      kind: PersistentVolumeClaim
      metadata:
        name: pvc-sfsturbo
        namespace: default
        annotations:
          volume.beta.kubernetes.io/storage-provisioner: everest-csi-provisioner
          everest.io/enterprise-project-id: <your_project_id>  # Project ID of the SFS Turbo volume.
      spec:
        accessModes:
        - ReadWriteMany                  # The value must be ReadWriteMany for SFS Turbo.
        resources:
          requests:
            storage: 500Gi               # SFS Turbo volume capacity.
        storageClassName: csi-sfsturbo       # Storage class of the SFS Turbo volume, which must be the same as that of the PV.
        volumeName: pv-sfsturbo    # PV name.

      Table 3 Key parameters

      Parameter	Mandatory	Description
      everest.io/enterprise-project-id	No	Project ID of the SFS Turbo volume. How to obtain: On the SFS console, click SFS Turbo in the left navigation pane. Click the name of the SFS Turbo file system to interconnect. On the Basic Info tab, find and click the enterprise project to go to the console, and copy the ID.
      storage	Yes	Requested capacity in the PVC, in Gi. The value must be the same as the storage size of the existing PV.
      storageClassName	Yes	Storage class name, which must be the same as the storage class of the PV in 1. The storage class name of SFS Turbo volumes is csi-sfsturbo.
      volumeName	Yes	PV name, which must be the same as the PV name in 1.

   2. Run the following command to create a PVC:

      kubectl apply -f pvc-sfsturbo.yaml

4. Create an application.
   1. Create a file named web-demo.yaml. In this example, the SFS Turbo volume is mounted to the /data path.

      apiVersion: apps/v1
      kind: Deployment
      metadata:
        name: web-demo
        namespace: default
      spec:
        replicas: 2
        selector:
          matchLabels:
            app: web-demo
        template:
          metadata:
            labels:
              app: web-demo
          spec:
            containers:
            - name: container-1
              image: nginx:latest
              volumeMounts:
              - name: pvc-sfsturbo-volume    #Volume name, which must be the same as the volume name in the volumes field.
                mountPath: /data  #Location where the storage volume is mounted.
            imagePullSecrets:
              - name: default-secret
            volumes:
              - name: pvc-sfsturbo-volume    #Volume name, which can be customized.
                persistentVolumeClaim:
                  claimName: pvc-sfsturbo    #Name of the created PVC.

   2. Run the following command to create an application to which the SFS Turbo volume is mounted:

      kubectl apply -f web-demo.yaml

      After the workload is created, you can try Verifying Data Persistence and Sharing.

Verifying Data Persistence and Sharing

1. View the deployed applications and files.
   1. Run the following command to view the created pod:

      kubectl get pod | grep web-demo

      Expected output:

      web-demo-846b489584-mjhm9   1/1     Running   0             46s
      web-demo-846b489584-wvv5s   1/1     Running   0             46s

   2. Run the following commands in sequence to view the files in the /data path of the pods:

      kubectl exec web-demo-846b489584-mjhm9 -- ls /data
      kubectl exec web-demo-846b489584-wvv5s -- ls /data

      If no result is returned for both pods, no file exists in the /data path.

2. Run the following command to create a file named static in the /data path:

   kubectl exec web-demo-846b489584-mjhm9 --  touch /data/static

3. Run the following command to view the files in the /data path:

   kubectl exec web-demo-846b489584-mjhm9 -- ls /data

   Expected output:

   static

4. Verify data persistence.
   1. Run the following command to delete the pod named web-demo-846b489584-mjhm9:

      kubectl delete pod web-demo-846b489584-mjhm9

      Expected output:

      pod "web-demo-846b489584-mjhm9" deleted

      After the deletion, the Deployment controller automatically creates a replica.

   2. Run the following command to view the created pod:

      kubectl get pod | grep web-demo

      The expected output is as follows, in which web-demo-846b489584-d4d4j is the newly created pod:

      web-demo-846b489584-d4d4j   1/1     Running   0             110s
      web-demo-846b489584-wvv5s    1/1     Running   0             7m50s

   3. Run the following command to check whether the files in the /data path of the new pod have been modified:

      kubectl exec web-demo-846b489584-d4d4j -- ls /data

      Expected output:

      static

      If the static file still exists, the data can be stored persistently.

5. Verify data sharing.
   1. Run the following command to view the created pod:

      kubectl get pod | grep web-demo

      Expected output:

      web-demo-846b489584-d4d4j   1/1     Running   0             7m
      web-demo-846b489584-wvv5s   1/1     Running   0             13m

   2. Run the following command to create a file named share in the /data path of either pod: In this example, select the pod named web-demo-846b489584-d4d4j.

      kubectl exec web-demo-846b489584-d4d4j --  touch /data/share

      Check the files in the /data path of the pod.

      kubectl exec web-demo-846b489584-d4d4j -- ls /data

      Expected output:

      share
      static

   3. Check whether the share file exists in the /data path of another pod (web-demo-846b489584-wvv5s) as well to verify data sharing.

      kubectl exec web-demo-846b489584-wvv5s -- ls /data

      Expected output:

      share
      static

      After you create a file in the /data path of a pod, if the file is also created in the /data path of another pods, the two pods share the same volume.

Related Operations