Help Center/ Cloud Container Engine/ User Guide/ Storage/ SFS/ Using an SFS File System Through a Dynamic PV

Updated on 2025-09-04 GMT+08:00

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Using an SFS File System Through a Dynamic PV

This section describes how to use StorageClasses to dynamically create PVs and PVCs for data persistence and sharing in workloads.

Prerequisites

You have created a cluster and installed the CCE Container Storage (Everest) add-on in the cluster.
To create a cluster using commands, ensure kubectl is used. For details, see Accessing a Cluster Using kubectl.
Before using a general purpose file system (SFS 3.0 Capacity-Oriented) for storage, ensure a VPC endpoint has been created in the VPC where the cluster is located for the cluster to access the file system. For details, see Configuring a VPC Endpoint.

Notes and Constraints

If a general purpose file system (SFS 3.0 Capacity-Oriented) is used, CCE Container Storage (Everest) of v2.0.9 or later must be installed in the cluster.
If a general purpose file system (SFS 3.0 Capacity-Oriented) is used, the owner group and permission of the mount point cannot be modified. The default owner of the mount point is user root.
If a general purpose file system (SFS 3.0 Capacity-Oriented) is used, there may be a latency during the creation or deletion of PVCs and PVs. The billing duration is determined by the time when the resource is created or deleted on the SFS console.
If the CCE Container Storage (Everest) version is earlier than 2.4.105 or the target region is CN South-Guangzhou, and the Delete reclaim policy is used for the general purpose file system (SFS 3.0 Capacity-Oriented), you must delete files from the file system. Otherwise, deleting the PVs and PVCs may fail. If the add-on version is 2.4.105 or later and the region is not CN South-Guangzhou, this restriction does not apply.

Dynamically Creating an SFS File System

CCE allows you to create SFS PVCs via the console or kubectl based on the configured StorageClasses. After PVC creation, CCE dynamically allocates storage resources and mounts the PVCs to the specified workloads. To do so, perform the following operations.

Dynamically create a PVC and PV.

Choose Storage in the navigation pane. In the right pane, click the PVCs tab. Click Create PVC in the upper right corner. In the dialog box displayed, configure PVC parameters.

Parameter	Description
PVC Type	In this example, select SFS.
PVC Name	Enter the PVC name, which must be unique in a namespace.
Creation Method	If no underlying storage is available, select Dynamically provision to create a PVC, PV, and underlying storage on the console in cascading mode. If underlying storage is available, create a PV or use an existing PV to statically create a PVC. For details, see Using an Existing SFS File System Through a Static PV. In this example, select Dynamically provision.
Storage Classes	The default StorageClass of SFS volumes is csi-sfs. You can customize a StorageClass and configure its reclaim policy and binding mode. For details, see Through the Console.
(Optional) Storage Volume Name Prefix	Available only when the cluster version is v1.23.14-r0, v1.25.9-r0, v1.27.6-r0, v1.28.4-r0, or later, and Everest of v2.4.15 or later is installed in the cluster. This parameter specifies the name of the underlying storage that is automatically created. The actual underlying storage name is in the format of "Storage volume name prefix + PVC UID". If this parameter is left blank, the default prefix pvc will be used. For example, if the storage volume name prefix is set to test, the actual underlying storage name is test-{UID}.
Access Mode	SFS 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.

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 PVCs and PVs tab pages, respectively.

Create an application.

Choose Workloads in the navigation pane. In the right pane, click the Deployments tab.

Click Create Workload in the upper right corner. On the displayed page, click Data Storage in the Container Information area under Container Settings and choose Add Volume > PVC.

Mount and use storage volumes. For details about the parameters, see Table 1. For other parameters, see Workloads.

**Table 1** Mounting a storage volume
Parameter	Description
PVC	Select an existing SFS volume.
Mount Path	Enter a mount path, for example, /tmp. This parameter specifies a container path to which a data volume will be mounted. Do not mount the volume to a system directory such as / or /var/run. This may lead to container errors. 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, leading to 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 may be damaged.
Subpath	Enter the subpath of the storage volume and mount a path in the storage volume to the container. In this way, different folders of the same storage volume can be used in a single pod. tmp, for example, indicates that data in the mount path of the container is stored in the tmp folder of the storage volume. If this parameter is left blank, the root path will be 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 will not be 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 file system.

Click to enlarge

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.

Use kubectl to access the cluster.

Use StorageClass to dynamically create a PVC and PV.

Create the pvc-sfs-auto.yaml file.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: pvc-sfs-auto
  namespace: default
  annotations: 



    everest.io/csi.volume-name-prefix: test  # (Optional) Storage volume name prefix of the automatically created underlying storage
spec:
  accessModes:
    - ReadWriteMany             # The value must be ReadWriteMany for SFS.
  resources:
    requests:
      storage: 1Gi             # SFS volume capacity
  storageClassName: csi-sfs    # The StorageClass is SFS. csi-sfs indicates that a general purpose file system (SFS 3.0 Capacity-Oriented) is used.

**Table 2** Key parameters
Parameter	Mandatory	Description
storage	Yes	Requested capacity in the PVC, in Gi. For SFS, this parameter is used only for verification (cannot be empty or 0). Its value is fixed at 1, and any value you set does not take effect for SFS file systems.
storageClassName	Yes	StorageClass name, which must be csi-sfs, indicating that a general purpose file system (SFS 3.0 Capacity-Oriented) is used.
everest.io/csi.volume-name-prefix	No	(Optional) This parameter is available only when the cluster version is v1.23.14-r0, v1.25.9-r0, v1.27.6-r0, v1.28.4-r0, or later, and Everest of v2.4.15 or later is installed in the cluster. This parameter specifies the name of the underlying storage that is automatically created. The actual underlying storage name is in the format of "Storage volume name prefix + PVC UID". If this parameter is left blank, the default prefix pvc will be used. Enter 1 to 26 characters that cannot start or end with a hyphen (-). Only lowercase letters, digits, and hyphens (-) are allowed. For example, if the storage volume name prefix is set to test, the actual underlying storage name is test-{UID}.

Run the following command to create a PVC:
```
kubectl apply -f pvc-sfs-auto.yaml
```

Create an application.

Create a file named web-demo.yaml. In this example, the SFS 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-sfs-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-sfs-volume    # Volume name, which can be customized
          persistentVolumeClaim:
            claimName: pvc-sfs-auto    # Name of the created PVC

Run the following command to create a workload to which the SFS volume is mounted:
```
kubectl apply -f web-demo.yaml
```
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.

Verifying Data Persistence and Sharing

View the deployed application 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 check 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.
Run the following command to create a file named static in the /data path:
```
kubectl exec web-demo-846b489584-mjhm9 --  touch /data/static
```
Run the following command to check the files in the /data path:
```
kubectl exec web-demo-846b489584-mjhm9 -- ls /data
```
Expected output:
```
static
```
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
```
  The static file is retained, indicating that the data in the file system can be stored persistently.
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 the other pod, the two pods share the same volume.

Related Operations

You can also perform the operations listed in Table 3.

**Table 3** Related operations
Operation	Description	Procedure
Viewing events	View event names, event types, number of occurrences, Kubernetes events, first occurrence time, and last occurrence time of the PVC or PV.	Choose Storage in the navigation pane. In the right pane, click the PVCs or PVs tab. Click View Events in the Operation column of the target PVC or PV to view events generated within one hour (events are retained for one hour).
Viewing a YAML file	View, copy, or download the YAML file of a PVC or PV.	Choose Storage in the navigation pane. In the right pane, click the PVCs or PVs tab. Click View YAML in the Operation column of the target PVC or PV to view or download the YAML.

Common Issues

Mounting a general purpose file system (SFS 3.0 Capacity-Oriented) timed out, and the error message is as follows:

MountVolume.SetUp failed for volume "***" : rpc error: code = Internal desc = [30834707-b8fc-11ee-ba7a-fa163eaacb17] failed to execute cmd: "systemd-run --scope  mount -t nfs -o proto=tcp -o vers=3 -o timeo=600 -o noresvport -o nolock ***.sfs3.cn-east-3.myhuaweicloud.com:/*** /mnt/paas/kubernetes/kubelet/pods/add9a323-10e2-434f-b151-42675f83860e/volumes/kubernetes.io~csi/***/mount". outputs: Running scope as unit run-1597979.scope.; error: signal: killed. please check whether the volumeAttributes of related PersistentVolume of the volume is correct and whether it can be mounted.

Solution

Create a VPC endpoint before using a general purpose file system (SFS 3.0 Capacity-Oriented). Otherwise, the cluster cannot access the general purpose file system (SFS 3.0 Capacity-Oriented). As a result, the mounting times out and fails. For details, see Configuring a VPC Endpoint.

Parent Topic: SFS

Previous topic: Using an Existing SFS File System Through a Static PV

Next topic: Creating an SFS Subdirectory Using a Dynamic PV

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