Persistent Volume Management

• 1: Configuring PVs
• 1.1: Configuring Dynamic PVs
• 1.2: Configuring a Static PV
• 1.3: Managing PVs
• 2: Managing PVs
• 2.1: Expanding the Capacity of a PV
• 2.2: Cloning a PV
• 2.3: Changing a PV
• 2.3.1: Enabling the PVC Change Feature
• 2.3.1.1: Enabling the PVC Change Feature Using Helm
• 2.3.1.2: Enabling the PVC Change Feature Manually
• 2.3.2: Configuring PVC Changes
• 2.3.2.1: Creating a PVC Change
• 2.3.2.2: Querying a PVC Change
• 2.3.2.3: Deleting a PVC Change

1 - Configuring PVs

Huawei CSI allows storage resources (LUNs or file systems) to be created on Huawei storage and provided for containers based on user settings. For details about the supported features, see Compatibility and Features of the storage device.

PV configurations can be classified into configuring dynamic PVs or static PVs, and managing PVs.

• Configuring dynamic PV does not require a PV to be created in advance. Huawei CSI automatically creates resources required by a PV on storage devices based on a StorageClass. In addition, you can create a PV when creating a PVC.
• Configuring a static PV requires the administrator to create required resources on a storage device in advance and use existing resources by creating a PV. In addition, you can specify the associated PV when creating a PVC.
• Managing PVs does not require a PV to be created in advance. You can specify the StorageClass and resource information on the storage device in a PVC. Create the PVC and PV at the same time, and manage all existing storage resources in the cluster.

1.1 - Configuring Dynamic PVs

Dynamic volume provisioning allows storage volumes to be created on demand. Dynamic volume provisioning depends on the StorageClass objects. The cluster administrator can define multiple StorageClass objects as required and specify a StorageClass that meets service requirements when declaring a PV or PVC. When applying for resources from Huawei storage devices, Huawei CSI creates storage resources that meet service requirements based on the preset StorageClass.

Configuration Description

Perform the following steps to configure and use dynamic PVs:

• Preparation
• Configuring a PVC
• Using a PVC

Preparation

Before configuring dynamic PVs, configure StorageClass by referring to Configuring a StorageClass .

Configuring a PVC

1. Prepare the PVC configuration file mypv.yaml. The following is an example. For details about other parameters, see Table 1 .

   kind: PersistentVolumeClaim
   apiVersion: v1
   metadata:
     name: mypvc
   spec:
     accessModes:
       - ReadWriteOnce
     volumeMode: Filesystem
     storageClassName: mysc
     resources:
       requests:
         storage: 100Gi
   

2. Run the following command to create a PVC using the configuration file.

   kubectl create -f mypvc.yaml
   

3. After a period of time, run the following command to view the information about the created PVC.

   kubectl get pvc mypvc
   

   The following is an example of the command output. If the PVC status is Bound, the PVC has been created and can be used by a Pod.

   NAME        STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
   mypvc       Bound    pvc-840054d3-1d5b-4153-b73f-826f980abf9e   100Gi      RWO            mysc           12s
   

   

   • After the PVC is created, if the PVC is in the Pending state after a long time (for example, one minute), refer to When a PVC Is Created, the PVC Is in the Pending State .
   • You are advised to create or delete a maximum of 100 PVCs in a batch.

Table 1 PVC parameters for configuring a dynamic PV

Table 2 ext4 capacity specifications

Table 3 XFS capacity specifications

Using a PVC

After a PVC is created, you can use the PVC to create a Pod. The following is a simple example of using a PVC. In this example, the created Pod uses the newly created mypvc.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  selector:
    matchLabels:
      app: nginx
  replicas: 2
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers: 
      - image: nginx:alpine
        name: container-0 
        volumeMounts: 
        - mountPath: /tmp
          name: pvc-mypvc 
      restartPolicy: Always 
      volumes: 
      - name: pvc-mypvc 
        persistentVolumeClaim: 
          claimName:  mypvc  # name of PVC

If Pods are batch created using PVCs, the Pods are in the ContainerCreating status for a long time, and the huawei-csi-node service is in the OOMKilled status, the memory of the huawei-csi-node service is insufficient. Increase the memory limit of huawei-csi-node by referring to Table 1 .

1.2 - Configuring a Static PV

Static volume provisioning allows administrators to use a resource created on the storage side as a PV for containers in the cluster.

Configuration Description

Perform the following steps to configure a static PV:

• Preparation
• Configuring a PV
• Configuring a PVC
• Using a PVC

Preparation

A storage resource, such as a LUN or file system, required by the PV to be created exists on the storage device. If the storage resource is a file system, you also need to create the share and client information of the file system.

Configuring a PV

1. Prepare the PV configuration file mypv.yaml. The following is an example. For details about other parameters, see Table 1 .

   kind: PersistentVolume
   apiVersion: v1
   metadata:
     name: mypv
   spec:
     volumeMode: Filesystem
     storageClassName: "" # The value must be to "".
     accessModes:
       - ReadWriteOnce
     csi:
       driver: csi.huawei.com # Enter the CSI driver name.
       volumeHandle: iscsi-dorado-181.lun0001 # Enter the volume name.
       fsType: xfs # Set the file system type.
     capacity:
       storage: 100Gi
   

   
   In the configuration file for static volume provisioning, storageClassName must be set to "". Otherwise, Kubernetes will use the default StorageClass.

2. Run the following command to create a PV based on the prepared .yaml file.

   kubectl create -f mypv.yaml
   

3. After a period of time, run the following command to view the information about the created PV.

   kubectl get pv
   

   The following is an example of the command output. If the PV status is Available, the PV is successfully created.

   NAME       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM               STORAGECLASS   REASON   AGE
   mypv       100Gi      RWO            Retain           Available                                               4s
   

Table 1 Parameters for configuring a static PV

Configuring a PVC

After a PV is created in static volume provisioning mode, you can create a PVC based on the PV for containers.

1. Prepare the PVC configuration file mypv.yaml. The following is an example. For details about other parameters, see Table 2 .

   kind: PersistentVolumeClaim
   apiVersion: v1
   metadata:
     name: mypvc
   spec:
     storageClassName: ""
     accessModes:
       - ReadWriteOnce
     volumeMode: Filesystem
     resources:
       requests:
         storage: 100Gi
     volumeName: mypv # Enter the name of the corresponding PV.
   

2. Run the following command to create a PVC based on the configured .yaml file.

   kubectl create -f mypvc.yaml
   

3. After a period of time, run the following command to view the information about the created PVC.

   kubectl get pvc
   

   The following is an example of the command output. If the PVC status is Bound, the PVC is successfully created.

   NAME        STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
   mypvc       Bound    pvc-840054d3-1d5b-4153-b73f-826f980abf9e   100Gi      RWO                           12s
   

   

   • After the PVC is created, if the PVC is in the Pending state after a long time, see When a PVC Is Created, the PVC Is in the Pending State .
   • You are advised to create or delete a maximum of 100 PVCs in a batch.

Table 2 PVC parameters for configuring a static PV

Using a PVC

The use method is the same as that for dynamic volume provisioning in Using a PVC .

1.3 - Managing PVs

Manage Volume Provisioning allows administrators to use resources created on storage as PVs and supports features of dynamic volumes, such as capacity expansion, snapshot, and clone. This is a custom capability of Huawei CSI. This feature applies to the following scenarios:

• In the reconstruction containerized applications, existing storage volumes need to be used.
• The Kubernetes cluster is rebuilt.
• Storage data is migrated in disaster recovery (DR) scenarios.

Manage Volume Provisioning allows existing storage resources to be managed by Kubernetes. You are not allowed to manage a storage resource for multiple times and concurrently delete or create a storage resource. When a storage resource is managed by multiple clusters, operations on the managed volume in a single cluster take effect only in the cluster and will not be synchronized to other clusters. Instead, you need to perform these operations on the managed volume in other clusters. For example, when you expand the capacity of a PVC in a cluster, the capacity of the corresponding PVC in other clusters will not be automatically expanded. In this case, you need to manually expand the capacity in other clusters by running the expansion commands in Expanding the Capacity of a PV .

Configuration Description

Perform the following steps to manage and use PVs:

• Preparation
• Configuring a PVC
• Using a PVC

Preparation

• You have registered the storage where the volume to be managed resides with CSI.
• You have logged in to the storage device to obtain the name and capacity of the volume to be managed.
• The StorageClass has been configured. For details, see Configuring a StorageClass (pay attention to the Whether the Volume Management Takes Effect field in the table).

Configuring a PVC

1. Prepare the PVC configuration file mypv.yaml. The following is an example. For details about other parameters, see Table 1 .

   kind: PersistentVolumeClaim
   apiVersion: v1
   metadata:
     name: mypvc
     annotations:
       csi.huawei.com/manageVolumeName: "*"  # Enter the storage resource name.
       csi.huawei.com/manageBackendName: "*" # Enter the storage backend name.
     labels:
       provisioner: csi.huawei.com
   spec:
     accessModes:
       - ReadWriteOnce
     volumeMode: Filesystem
     storageClassName: mysc
     resources:
       requests:
         storage: 100Gi
   

2. Run the following command to create a PVC using the configuration file.

   kubectl create -f mypvc.yaml
   

3. After a period of time, run the following command to view the information about the created PVC.

   kubectl get pvc mypvc
   

   The following is an example of the command output. If the PVC status is Bound, the PVC has been created and can be used by a Pod.

   NAME        STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
   mypvc       Bound    pvc-840054d3-1d5b-4153-b73f-826f980abf9e   100Gi      RWO            mysc           12s
   

   

   • After the PVC is created, if the PVC is in the Pending state after a long time (for example, one minute), refer to When a PVC Is Created, the PVC Is in the Pending State .
   • You are advised to create or delete a maximum of 100 PVCs in a batch.

Table 1 PVC parameters for managing PVs

Using a PVC

The procedure is the same as that for Using a PVC for dynamic volume provisioning.

2 - Managing PVs

2.1 - Expanding the Capacity of a PV

For OceanStor V700R001C10 as well as OceanStor Dorado V700R001C10 and later versions, the minimum capacity of a file system after capacity expansion is limited. For details, see the product documentation of the corresponding storage device.

When the capacity of a PVC used by a container is insufficient, you need to expand the capacity of the PVC.

Prerequisites

• A PVC has been created, the backend to which it resides exists and supports capacity expansion.

• Compatibility and Features lists the storage that supports capacity expansion, and Kubernetes Feature Matrix lists the Kubernetes versions that support capacity expansion.

• The csi-resizer service is enabled for huawei-csi-controller.

  kubectl describe deploy huawei-csi-controller -n huawei-csi | grep csi-resizer
  

  If the following information is displayed, the csi-resizer service is enabled.

     csi-resizer:
      Image:      k8s.gcr.io/sig-storage/csi-resizer:v1.9.0
  

Procedure

1. Run the following command to check whether the StorageClass supports capacity expansion. In the preceding command, mysc indicates the name of the StorageClass to be queried.

   kubectl get sc mysc
   

   The following is an example of the command output.

   NAME              PROVISIONER      RECLAIMPOLICY   VOLUMEBINDINGMODE   ALLOWVOLUMEEXPANSION   AGE
   mysc              csi.huawei.com   Delete          Immediate           true                  172m
   

   If the value of ALLOWVOLUMEEXPANSION is true, the current StorageClass supports capacity expansion. In this case, go to 3 .

2. Run the following command to change the value of allowVolumeExpansion to true. In the preceding command, mysc indicates the name of the StorageClass to be modified.

   kubectl patch sc mysc --patch '{"allowVolumeExpansion":true}'
   

3. Run the following command to query the StorageClass name of the PVC. In the preceding command, mypvc indicates the name of the PVC to be expanded.

   kubectl get pvc mypvc
   

   The following is an example of the command output.

   NAME               STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS      AGE
   mypvc              Bound    pvc-3383be36-537c-4cb1-8f32-a415fa6ba384   2Gi        RW0            mysc              145m
   

4. Run the following command to expand the capacity.

   kubectl patch pvc mypvc -p '{"spec":{"resources":{"requests":{"storage":"120Gi"}}}}'
   

   In the preceding command, mypvc indicates the name of the PVC to be expanded, and 120Gi indicates the capacity after expansion. Change the values based on the site requirements.

   

   • The PVC capacity depends on storage specifications and host specifications. For example, OceanStor Dorado 6.1.2 or OceanStor Pacific series 8.1.0 is connected to CentOS 7. If ext4 file systems are used, see Table 2 . If XFS file systems are used, see Table 3 . If NFS or raw devices are used, the capacity must meet the specifications of the used Huawei storage device model and version.
   • If the PVC capacity does not meet the specifications, a PVC or Pod may fail to be created due to the limitations of storage specifications or host file system specifications.
   • If the capacity expansion fails because the target capacity exceeds the storage pool capacity, see Failed to Expand the PVC Capacity Because the Target Capacity Exceeds the Storage Pool Capacity .

5. Run the following command to check whether the capacity modification takes effect.

   kubectl get pvc
   

   The following is an example of the command output. If the value of CAPACITY is changed to the specified capacity, the capacity expansion is successful.

   NAME        STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
   mypvc       Bound    pvc-3383be36-537c-4cb1-8f32-a415fa6ba384   120Gi       RWO            mysc           24s
   

2.2 - Cloning a PV

This section describes how to clone a PVC.

When cloning a PVC, you need to specify the data source. The following is an example of cloning a PVC. In this example, mypvc is used as the data source and a PVC named myclone is created.

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: myclone
spec:
  storageClassName: mysc
  dataSource:
    name: mypvc
    kind: PersistentVolumeClaim
  volumeMode: Filesystem
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 2Gi

• The specified storageClassName must be the same as the StorageClass of the source volume in dataSource.
• The capacity of the clone volume must be greater than or equal to that of the source volume. Equal capacity is recommended.

Prerequisites

The source PVC already exists in the system, and the backend where the source PVC resides supports cloning. Compatibility and Features lists the storage that supports cloning, and Kubernetes Feature Matrix lists the Kubernetes versions that support cloning.

Procedure

1. Run the following command to create a PVC based on the configuration file of the clone volume.

   kubectl create -f myclone.yaml
   

2.3 - Changing a PV

2.3.1 - Enabling the PVC Change Feature

The PVC change feature is disabled by default during Huawei CSI installation. To use this feature, perform the following steps.

2.3.1.1 - Enabling the PVC Change Feature Using Helm

Prerequisites

You have installed Huawei CSI using Helm.

Procedure

1. Use a remote access tool, such as PuTTY, to log in to any master node in the Kubernetes cluster through the management IP address.

2. Run the following command to check whether the PVC change feature is enabled.

   helm-huawei-csi indicates the Helm chart name specified during installation, and huawei-csi indicates the Helm chart namespace specified during installation. For details about the component package path, see Table 1 .

   helm get values helm-huawei-csi -n huawei-csi -a | grep volumeModify -A 1
   

   The following is an example of the command output.

   • If enabled: true is displayed in the command output, the feature is enabled. In this case, skip the following steps.
   • If enabled: false is displayed in the command output, perform the following steps to enable the PVC change feature.

   volumeModify:
     enabled: false
   

3. Go to the /helm/esdk directory and run the following command to configure the volume change CRD.

   # kubectl apply -f ./crds/volume-modify/
   customresourcedefinition.apiextensions.k8s.io/volumemodifyclaims.xuanwu.huawei.io configured
   customresourcedefinition.apiextensions.k8s.io/volumemodifycontents.xuanwu.huawei.io configured
   

   
   If the command output contains Warning: resource customresourcedefinitions/volumemodifycontents.xuanwu.huawei.io is missing the kubectl.kubernetes.io/last-applied-configuration…, you can ignore it. This message is displayed because the kubectl create command instead of the kubectl apply command is used for installation by Helm.

4. Run the following command to obtain the original service configuration file.

   helm get values helm-huawei-csi -n huawei-csi -a > ./update-values.yaml
   

5. Run the vi update-values.yaml command to open the file obtained in 4 and modify the following configuration. After the modification is complete, press Esc and enter :wq! to save the modification.

   csiExtender:
     volumeModify:    
       enabled: true
   

6. Run the following command to update Huawei CSI services.

   helm upgrade helm-huawei-csi ./ -n huawei-csi  -f ./update-values.yaml
   

7. Run the following command to check whether the services are started.

   kubectl get pod -n huawei-csi
   

   The following is an example of the command output. In the preceding command, huawei-csi indicates the namespace for deploying Huawei CSI.

   NAME                                     READY     STATUS    RESTARTS   AGE
   huawei-csi-controller-6dfcc4b79f-9vjtq   10/10     Running   0          24m
   huawei-csi-node-tqs87                    3/3       Running   0          20m
   

2.3.1.2 - Enabling the PVC Change Feature Manually

Prerequisites

Huawei CSI has been manually installed.

Procedure

1. Use a remote access tool, such as PuTTY, to log in to any master node in the Kubernetes cluster through the management IP address.

2. Go to the manual/esdk working directory and run the following command to configure the volume change CRD.

   kubectl apply -f ./crds/volume-modify/
   

3. Run the following command. For details about the component package path, see Table 1 .

   kubectl apply -f ./deploy/huawei-csi-controller-extender.yaml
   

4. Run the following command to check whether the services are started.

   kubectl get pod -n huawei-csi
   

   The following is an example of the command output. In the preceding command, huawei-csi indicates the namespace for deploying Huawei CSI.

   NAME                                     READY     STATUS    RESTARTS   AGE
   huawei-csi-controller-6dfcc4b79f-9vjtq   10/10     Running   0          24m
   huawei-csi-node-tqs87                    3/3       Running   0          24m
   

2.3.2 - Configuring PVC Changes

The PVC change feature is implemented using CRD. Related resources are described as follows.

Table 1 Resource description

• VolumeModifyClaim resources can be created, deleted, and queried, but cannot be updated.
• VolumeModifyContent resources can only be queried and are used to display the change details of a single PVC. Do not manually create, delete, or modify the resources.
• VolumeModifyContent resources are managed by VolumeModifyClaim. Do not manually manage VolumeModifyContent resources.

2.3.2.1 - Creating a PVC Change

Prerequisites

The storage backends associated with the PVC to be changed are HyperMetro storage backends. If they are not HyperMetro storage backends, configure them by following the instructions in Updating a Storage Backend .

PVC Change File Description

The sample template of the PVC change file is /examples/volumemodifyclaim.yaml. The following table lists the configuration items.

Table 1 Parameter description

• The spec.source.kind and spec.source.name parameters are used to specify the volume change scope. For example, if they are set to a StorageClass and the corresponding name respectively, all PVCs in the Bound state provisioned using the target StorageClass will be changed.
• After all associated PVCs are changed, Huawei CSI will replace the original StorageClass and add the spec.parameters parameter of the VolumeModifyClaim so that the PVCs meet the StorageClass definition.

For details about the configuration in typical scenarios, see the following example:

Changing a Common Volume to a HyperMetro Volume

The following is an example of changing a common volume to a HyperMetro volume:

apiVersion: xuanwu.huawei.io/v1
kind: VolumeModifyClaim
metadata:
  name: myvmc
spec:
  source:
    kind: StorageClass
    name: mysc
  parameters:
    hyperMetro: "true"

Creating a PVC Change Resource

• The changed HyperMetro volumes must be in HyperMetro AA mode.
• When a common volume is changed to a HyperMetro volume, only the storage volume at the primary site can be changed.
• Do not use Huawei CSI to manage a PVC during PVC change resource creation.
• Multiple VolumeModifyClaim resources cannot be created for the same PVC. If the target PVC needs to be changed for multiple times, perform the changes one by one.

To create a PVC change resource using a PVC change file, perform the following steps:

1. Use a remote access tool, such as PuTTY, to log in to any master node in the Kubernetes cluster through the management IP address.

2. Run the following command to create a PVC change.

   kubectl create -f volumemodifyclaim.yaml 
   

3. Query the creation result by following the instructions in Querying a PVC Change .

2.3.2.2 - Querying a PVC Change

This section describes how to use Kubectl to query the PVC change status. Currently, Huawei CSI provides the following APIs through CRD.

Querying a VolumeModifyClaim

To query a VolumeModifyClaim using kubectl, perform the following steps.

1. Use a remote access tool, such as PuTTY, to log in to any master node in the Kubernetes cluster through the management IP address.

2. Run the following command to query a PVC change. In the command, vmc-name indicates the name of the VolumeModifyClaim resource.

   kubectl get volumemodifyclaims <vmc-name> -owide
   

   The following is an example of the command output.

   NAME    STATUS      READY   SOURCEKIND     SOURCENAME   STARTEDAT              COMPLETEDAT            AGE
   myvmc   Completed   1/1     StorageClass   mysc         2024-06-06T03:19:13Z   2024-06-06T03:19:16Z   2m2s
   

   Table 1 Command output description

   Parameter	Description
   NAME	VolumeModifyClaim resource name.
   STATUS	VolumeModifyClaim resource status. The value can be: Pending: initial status. Creating: The VolumeModifyClaim has completed basic verification and the server has received the change task, but the task has not been completed. Completed: All associated PVCs are changed. Rollback: When associated PVCs are partially changed, a user deletes PVCs. Deleting: When all associated PVCs are changed, a user deletes PVCs.
   READY	Ratio of the number of changed PVCs to the total number of PVCs that need to be changed.
   SOURCEKIND	Data source type, for example, StorageClass.
   SOURCENAME	Data source name, for example, StorageClass name.
   STARTEDAT	Change start time, that is, the timestamp when the server receives the task and starts to process the task.
   COMPLETEDAT	Change completion time, that is, the timestamp when the changes of all associated PVCs are complete. This parameter exists only when STATUS is Completed.
   AGE	Lifetime of a VolumeModifyClaim from the time when it is created to the current time.

You can use kubectl to view the Events information of a VolumeModifyClaim. If a VolumeModifyClaim cannot meet the creation requirements or an error occurs during the creation, the server will record the Events information. The following command is used as an example:

kubectl describe volumemodifyclaims local-to-hypermetro 

Querying a VolumeModifyContent

A VolumeModifyContent is created using a VolumeModifyClaim and records the change details of a single PVC. To query a VolumeModifyContent using kubectl, perform the following steps:

1. Use a remote access tool, such as PuTTY, to log in to any master node in the Kubernetes cluster through the management IP address.

2. Run the following command to query a PVC change. In the command, myvmc-uid indicates the VolumeModifyContent resource name.

   kubectl get volumemodifycontents myvmc-uid  -owide
   

   The following is an example of the command output.

   NAME         STATUS      MODIFYCLAIMNAME     SOURCEVOLUME   STARTEDAT              COMPLETEDAT            AGE
   myvmc-uid    Completed   myvmc               default/mypvc  2024-06-06T03:19:07Z   2024-06-06T03:19:09Z   36m
   

   Table 2 Command output description

   Parameter	Description
   NAME	VolumeModifyContent resource name. The format is VolumeModifyClaim name-UID of the associated PVC.
   STATUS	VolumeModifyContent resource status. The value can be: Pending: initial status. Creating: The VolumeModifyContent has completed basic verification and the server has received the change task, but the task has not been completed. Completed: The associated PVC is changed. Rollback: The PVC change is being rolled back.
   MODIFYCLAIMNAME	Name of the associated VolumeModifyClaim.
   SOURCEVOLUME	Information about the associated PVC. The format is Namespace name/PVC name.
   STARTEDAT	PVC change start time, that is, the timestamp when the server receives the task and starts to process the task.
   COMPLETEDAT	PVC change completion time, that is, the timestamp when the changes of all associated PVCs are complete. This parameter exists only when STATUS is Completed.
   AGE	Lifetime of a VolumeModifyContent from the time when it is created to the current time.

You can use kubectl to view the Events information of a VolumeModifyContent. If a VolumeModifyContent cannot meet the creation requirements or an error occurs during the PVC change, the server will record the Events information. The following command is used as an example:

kubectl describe volumemodifycontents myvmc-uid

2.3.2.3 - Deleting a PVC Change

• If STATUS of a VolumeModifyClaim is Creating, deleting the VolumeModifyClaim resource will delete the created resource on the storage side and then remove the cluster resource. After the deletion, if you continue to use the original StorageClass for PVC management, you need to restore the associated storage backend to a non-HyperMetro storage backend.
• If STATUS of a VolumeModifyClaim is Pending or Completed, deleting the VolumeModifyClaim resource will only remove the cluster resource and will not delete the created resource on the storage side (that is, there is not interaction with the storage side).
• VolumeModifyContent resources are managed by VolumeModifyClaim. Do not manually manage VolumeModifyContent resources.
• If some PVCs among the PVCs to be changed meet the change requirements and the batch change fails, all PVC changes will be removed. As a result, the PVCs that meet the change requirements will not meet the change requirements.
• If a PVC to be changed has been manually managed on the storage side, the change may fail. Do not manually manage storage volumes when using the change feature.

This section describes how to use kubectl to delete a PVC change. The procedure is as follows.

Procedure

1. Use a remote access tool, such as PuTTY, to log in to any master node in the Kubernetes cluster through the management IP address.

2. Run the following command to delete a PVC change. In the command, vmc-name indicates the name of the VolumeModifyClaim resource.

   kubectl delete volumemodifyclaims <vmc-name>
   

3. Query the creation result by following the instructions in Querying a PVC Change .