Import a preexisting Azure Disk volume

If you already have an Azure Disk volume to use with Anthos clusters on Azure, you can create a PersistentVolume (PV) object and reserve it for a specific PersistentVolumeClaim (PVC).

This page explains how to create a PV by using an existing volume populated with data, and how to use the PV in a Pod.

Before you begin

• Connect to your cluster

Create a PersistentVolume for a pre-existing volume

You can import an existing volume by specifying a new PV.

1. Copy the following YAML into a file named existing-volume.yaml.:

   apiVersion: v1
   kind: PersistentVolume
   metadata:
     name: VOLUME_NAME
     annotations:
       pv.kubernetes.io/provisioned-by: disk.csi.azure.com
   spec:
     capacity:
       storage: VOLUME_CAPACITY
     accessModes:
       - ReadWriteOnce
     persistentVolumeReclaimPolicy: Retain
     storageClassName: STORAGE_CLASS_NAME
     claimRef:
       name: my-pvc
       namespace: default
     csi:
       driver: disk.csi.azure.com
       volumeHandle: /subscriptions/SUBSCRIPTION_ID/resourcegroups/RESOURCE_GROUP_NAME/providers/microsoft.compute/disks/DISK_NAME
       fsType: FILE_SYSTEM_TYPE
   

   Replace the following:

   • VOLUME_NAME: a name for the volume
   • VOLUME_CAPACITY: size of the volume. For example, 30Gi. For more information on specifying volume capacity in Kubernetes, see the Meaning of memory.

   • STORAGE_CLASS_NAME: the name of the StorageClass that provisions the volume. For example, you can use the default standard-rwo.

     Note: A StorageClass is required to reference other attributes like allowVolumeExpansion, even if a volume is not dynamically provisioned.

   • SUBSCRIPTION_ID: the Azure subscription ID that contains the volume.

   • RESOURCE_GROUP_NAME: the Azure resource group that contains the volume.

   • DISK_NAME: the Azure Disk name of the volume.

   • FS_TYPE: the file system type of the volume. For example, ext4.

2. Apply the YAML to your cluster

   kubectl apply -f existing-volume.yaml
   

3. Confirm the creation of your PV

   kubectl describe pv VOLUME_NAME
   

   The output of this command contains the status of the PV.

Use the volume with a PersistentVolumeClaim and Pod

After you have imported your volume, you can create a PVC and a Pod that mounts the PVC.

1. The following YAML creates a PVC and attaches it to a Pod running the Nginx web server. Copy it into a file named nginx.yaml:

   apiVersion: v1
   kind: PersistentVolumeClaim
   metadata:
     name: my-pvc
   spec:
     storageClassName: STORAGE_CLASS_NAME
     volumeName: VOLUME_NAME
     accessModes:
       - ACCESS_MODE
     resources:
       requests:
         storage: VOLUME_CAPACITY
   ---
   
   apiVersion: v1
   kind: Pod
   metadata:
     name: web-server
   spec:
     containers:
      - name: web-server
        image: nginx
        volumeMounts:
          - mountPath: /var/lib/www/html
            name: data
     volumes:
      - name: data
        persistentVolumeClaim:
          claimName: my-pvc
   

   Replace the following:

   • STORAGE_CLASS: the name of the StorageClass from the PersistentVolume you created previously. For example, standard-rwo.
   • ACCESS_MODE: the access mode of the volume. For Azure Disk, use ReadWriteOnce. For Azure File, use ReadWriteMany.
   • VOLUME_CAPACITY: size of the volume. For example, 30Gi.

2. Apply the YAML to your cluster

   kubectl apply -f nginx.yaml
   

3. Check the status of your Nginx instance with kubectl describe. The output should have a STATUS of Running.

   kubectl describe pod web-server
   

What's next

• Use additional storage drivers with Anthos clusters on Azure.
• Read the documentation for the Azure Disk CSI driver.