Configure VolumeAttributesClass for Persistent Volumes

A VolumeAttributesClass is a Kubernetes resource that enables you to modify the attributes of an existing Persistent Volume (PV) without recreating it.

It defines a group of storage attributes that you can change on an existing volume. These settings act as a “profile” that you attach to a PersistentVolumeClaim (PVC). To use this feature, the underlying CSI driver must support the Kubernetes ModifyVolume API.

Percona Operator for MongoDB supports VolumeAttributesClass through references in the PVC templates you define in the cluster’s Custom Resource (CR).

This page explains when to use VolumeAttributesClass and how to configure it for Percona Operator deployments.

When to use a VolumeAttributesClass?

You can use a VolumeAttributesClass to adjust the storage performance of an existing volume. Typical use cases include:

• Increasing provisioned IOPS
• Adjusting throughput
• Switching performance tiers
• Enabling storage features supported by the CSI backend

Unlike a StorageClass, which defines how a volume is created, a VolumeAttributesClass defines how a volume is modified after creation.

Read more about VolumeAttributesClass in the Kubernetes documentation .

How to configure a VolumeAttributesClass

Requirements

To use VolumeAttributesClass, your environment must meet the following requirements:

• Kubernetes version 1.34 and above that supports the VolumeAttributesClass API.
• The VolumeAttributesClass feature gate is enabled for your Kubernetes cluster.

• A CSI driver that supports ModifyVolume. The example of such driver on GKE is pd.csi.storage.gke.io. You can check the list of CSI drivers with the following command:

  kubectl get storageclasses
  

  Expected output

  NAME                     PROVISIONER             RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
  premium-rwo              pd.csi.storage.gke.io   Delete          WaitForFirstConsumer   true                   5h18m
  standard                 kubernetes.io/gce-pd    Delete          Immediate              true                   5h18m
  standard-rwo (default)   pd.csi.storage.gke.io   Delete          WaitForFirstConsumer   true                   5h18m
  

• PersistentVolumes provisioned through that CSI driver.

Steps

To configure a VolumeAttributesClass, you need to create a VolumeAttributesClass resource. The resource defines the storage attributes that you can change on an existing volume.

1. Create a VolumeAttributesClass configuration file. For example, volume-attributes-class.yaml:

   volume-attributes-class.yaml

   apiVersion: storage.k8s.io/v1
   kind: VolumeAttributesClass
   metadata:
     name: silver
   driverName: pd.csi.storage.gke.io
   parameters:
     provisioned-iops: "3000"
     provisioned-throughput: "50"
   

2. Apply the configuration file to create the VolumeAttributesClass resource:

   kubectl apply -f volume-attributes-class.yaml -n <namespace>
   

3. Check that the VolumeAttributesClass is created:

   kubectl get volumeattributesclass -n <namespace>
   

   Expected output

   NAME     DRIVERNAME              AGE
   silver   pd.csi.storage.gke.io   9m32s
   

4. Reference the VolumeAttributesClass in the PVC template in your cluster’s Custom Resource (CR). For example, edit the deploy/cr.yaml file and add the following:

   replsets:
   - name: rs0
     ...
     volumeSpec:
       persistentVolumeClaim:
         volumeAttributesClassName: silver
         resources:
           requests:
             storage: 3Gi
   

5. Apply the changes to your cluster:

   kubectl apply -f deploy/cr.yaml -n <namespace>
   

   Behavior

   The Operator applies VolumeAttributesClass only to new PVCs when they are created. It does not update existing PVCs automatically. To apply a VolumeAttributesClass to an existing PVC, either patch the PVC manually or trigger the Operator to recreate the PVC.

6. Verify that the VolumeAttributesClass was applied to the PVC:

   kubectl get pvc my-cluster-name-rs0-0 -n <namespace> -o yaml
   

   Expected output

   {.text .no-copy} apiVersion: v1 kind: PersistentVolumeClaim metadata: name: my-cluster-name-rs0-0 ... spec: accessModes: - ReadWriteOnce resources: requests: storage: 3Gi storageClassName: standard-rwo volumeAttributesClassName: silver volumeMode: Filesystem

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Last update: February 25, 2026
Created: February 25, 2026