KubeBlocks
BlogsEnterprise
⌘K
​
Blogs

Overview
Quickstart
Architecture

Operations

Lifecycle Management
Vertical Scaling
Horizontal Scaling
Volume Expansion
Switchover
Minor Version Upgrade
Manage Services

Backup & Restore

Backup
Restore

Observability

Observability for etcd Clusters
  1. Prerequisites
  2. Check Current Storage
  3. Apply Volume Expansion
  4. Verify Expansion
  5. Cleanup

Volume Expansion for etcd Clusters with KubeBlocks

This guide explains how to expand the storage volume of an etcd cluster managed by KubeBlocks.

NOTE

Volume expansion requires that the underlying StorageClass supports volume expansion (allowVolumeExpansion: true). You can only increase volume size, not decrease it.

Prerequisites

    Before proceeding, verify your environment meets these requirements:

    • A functional Kubernetes cluster (v1.21+ recommended)
    • kubectl v1.21+ installed and configured with cluster access
    • Helm installed (installation guide)
    • KubeBlocks installed (installation guide)
    • etcd Add-on installed and an etcd cluster running (see Quickstart)

    Check Current Storage

    kubectl get pvc -n demo -l app.kubernetes.io/instance=etcd-cluster
    Example Output
    NAME                       STATUS   VOLUME       CAPACITY   ACCESS MODES   STORAGECLASS    AGE
data-etcd-cluster-etcd-0   Bound    pvc-xxx      20Gi       RWO            kb-default-sc   10m
data-etcd-cluster-etcd-1   Bound    pvc-xxx      20Gi       RWO            kb-default-sc   10m
data-etcd-cluster-etcd-2   Bound    pvc-xxx      20Gi       RWO            kb-default-sc   10m

    Apply Volume Expansion

    Expand the data volume from 20Gi to 30Gi:

    apiVersion: operations.kubeblocks.io/v1alpha1
kind: OpsRequest
metadata:
  name: etcd-volumeexpansion
  namespace: demo
spec:
  clusterName: etcd-cluster
  type: VolumeExpansion
  volumeExpansion:
  - componentName: etcd
    volumeClaimTemplates:
    - name: data
      storage: 30Gi

    Apply it:

    kubectl apply -f https://raw.githubusercontent.com/apecloud/kubeblocks-addons/refs/heads/main/examples/etcd/volumeexpand.yaml

    Monitor the progress:

    kubectl get ops etcd-volumeexpansion -n demo -w
    Example Output
    NAME                   TYPE              CLUSTER        STATUS    PROGRESS   AGE
etcd-volumeexpansion   VolumeExpansion   etcd-cluster   Running   0/3        10s
etcd-volumeexpansion   VolumeExpansion   etcd-cluster   Running   1/3        20s
etcd-volumeexpansion   VolumeExpansion   etcd-cluster   Running   2/3        33s
etcd-volumeexpansion   VolumeExpansion   etcd-cluster   Running   3/3        45s
etcd-volumeexpansion   VolumeExpansion   etcd-cluster   Succeed   3/3        47s

    Update the storage request in the Cluster spec:

    kubectl patch cluster etcd-cluster -n demo --type=json \
  -p='[{"op": "replace", "path": "/spec/componentSpecs/0/volumeClaimTemplates/0/spec/resources/requests/storage", "value": "30Gi"}]'

    Monitor the cluster status:

    kubectl get cluster etcd-cluster -n demo -w

    Verify Expansion

    kubectl get pvc -n demo -l app.kubernetes.io/instance=etcd-cluster
    Example Output
    NAME                       STATUS   VOLUME       CAPACITY   ACCESS MODES   STORAGECLASS    AGE
data-etcd-cluster-etcd-0   Bound    pvc-xxx      30Gi       RWO            kb-default-sc   12m
data-etcd-cluster-etcd-1   Bound    pvc-xxx      30Gi       RWO            kb-default-sc   12m
data-etcd-cluster-etcd-2   Bound    pvc-xxx      30Gi       RWO            kb-default-sc   12m

    Cleanup

    kubectl delete cluster etcd-cluster -n demo
kubectl delete ns demo

    © 2026 KUBEBLOCKS INC