Persistent Volumes are provisioned on Local Datastores Instead of vSAN

Products

• Tanzu Kubernetes Runtime

Issue/Introduction

• Persistent Volumes (PVs) created via the default StorageClass are unexpectedly provisioned on node-local datastores (e.g., local boot volumes or scratch disks) instead of the shared vSAN datastore.
• The PVs may become inaccessible if the pod is rescheduled to a different node, as the local storage is not shared across the cluster.

Environment

2.x

Cause

• The default StorageClass configuration is missing the storagePolicyName parameter.
• The csi.vsphere.vmware.com provisioner relies on vSphere Storage Policy Based Management (SPBM) to determine where to place volumes.
• If the storagePolicyName parameter is omitted from the StorageClass, the CSI driver does not enforce any specific placement rules.
• Hence, vCenter may select any available datastore accessible to the host—including local, non-shared datastores—to satisfy the volume creation request
  
  Example of incorrect configuration:
  
  

  apiVersion: storage.k8s.io/v1
  kind: StorageClass
  metadata:
    name: default
  provisioner: csi.vsphere.vmware.com
  # Missing parameters section defining the storage policy

Resolution

To ensure PVs are correctly provisioned on vSAN, define a StorageClass that explicitly references a vSphere Storage Policy compatible with your vSAN datastore.

1. Identify the Correct vSphere Storage Policy

1. Log in to the vSphere Client.

2. Navigate to Policies and Profiles > VM Storage Policies.

3. Identify the policy used for your vSAN (e.g., "vSAN Default Storage Policy" or "Tanzu Storage Policy").

4. Note the exact name (case-sensitive).

2. Create a New StorageClass Definition

Create a YAML file (e.g., vsan-storageclass.yaml) with the following content. Ensure you update the storagePolicyName to match the policy identified in Step 1.

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: vsan-default
  annotations:
    storageclass.kubernetes.io/is-default-class: "true"
provisioner: csi.vsphere.vmware.com
parameters:
  storagePolicyName: "vSAN Default Storage Policy"  # Update this name to match your environment
reclaimPolicy: Delete
volumeBindingMode: WaitForFirstConsumer

3. Apply the New StorageClass

1.  Remove default annotation from the old class:
   
   kubectl patch storageclass default -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"false"}}}'
   
   
2. Apply the new StorageClass:
   
   kubectl apply -f vsan-storageclass.yaml