GKE Storage Guide

Complete guide to persistent storage in Google Kubernetes Engine (GKE), including PersistentVolumes, PersistentVolumeClaims, StorageClasses, and StatefulSets.

Storage Overview

Key Storage Concepts

Concept	Description
PersistentVolume (PV)	Storage resource provisioned in the cluster
PersistentVolumeClaim (PVC)	Request for storage by a Pod
StorageClass	Template for dynamic volume provisioning
CSI Driver	Container Storage Interface plugin
StatefulSet	Workload controller with stable storage

PersistentVolumes and Claims

How Dynamic Provisioning Works

Create a PersistentVolumeClaim

yaml

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: my-pvc
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 30Gi
  storageClassName: standard-rwo

Use PVC in a Pod

yaml

apiVersion: v1
kind: Pod
metadata:
  name: my-pod
spec:
  containers:
  - name: app
    image: nginx
    volumeMounts:
    - mountPath: /data
      name: my-volume
  volumes:
  - name: my-volume
    persistentVolumeClaim:
      claimName: my-pvc

StorageClasses

Default StorageClasses in GKE

StorageClass	Disk Type	Use Case
standard-rwo	pd-balanced	General purpose (default)
premium-rwo	pd-ssd	High IOPS workloads
standard	pd-standard	Cost-effective, sequential I/O

Custom StorageClass

yaml

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: fast-storage
provisioner: pd.csi.storage.gke.io
parameters:
  type: pd-ssd
  csi.storage.k8s.io/fstype: ext4
volumeBindingMode: WaitForFirstConsumer
reclaimPolicy: Delete
allowVolumeExpansion: true

StorageClass Parameters

Parameter	Description
provisioner	CSI driver (pd.csi.storage.gke.io)
type	Disk type (pd-balanced, pd-ssd, pd-standard)
fstype	Filesystem type (ext4, xfs)
volumeBindingMode	When to provision (Immediate, WaitForFirstConsumer)
reclaimPolicy	What happens on PVC delete (Delete, Retain)
allowVolumeExpansion	Allow online volume resize

Access Modes

Access Mode	Description	Supported By
ReadWriteOnce (RWO)	Single node read-write	Persistent Disk
ReadOnlyMany (ROX)	Multi-node read-only	Persistent Disk
ReadWriteMany (RWX)	Multi-node read-write	Filestore, Cloud Storage FUSE
ReadWriteOncePod (RWOP)	Single Pod read-write	Persistent Disk

Regional Persistent Disks

High availability storage with synchronous replication across two zones.

Regional PD StorageClass

yaml

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: regional-pd
provisioner: pd.csi.storage.gke.io
parameters:
  type: pd-ssd
  replication-type: regional-pd
volumeBindingMode: WaitForFirstConsumer

Regional PD Benefits

Benefit	Description
High Availability	Survives single zone failure
Auto Failover	GKE reschedules Pods to healthy zone
RPO = 0	Synchronous replication, no data loss

StatefulSets

StatefulSets are the recommended way to deploy stateful applications.

StatefulSet Example

yaml

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web
spec:
  serviceName: web-headless
  replicas: 3
  selector:
    matchLabels:
      app: web
  template:
    metadata:
      labels:
        app: web
    spec:
      containers:
      - name: nginx
        image: nginx
        volumeMounts:
        - name: data
          mountPath: /usr/share/nginx/html
  volumeClaimTemplates:
  - metadata:
      name: data
    spec:
      accessModes: ["ReadWriteOnce"]
      storageClassName: standard-rwo
      resources:
        requests:
          storage: 10Gi

StatefulSet vs Deployment

Feature	StatefulSet	Deployment
Pod naming	Ordered (pod-0, pod-1)	Random suffix
Storage	Unique PVC per Pod	Shared PVC
Scaling	Ordered (0,1,2...)	Parallel
Updates	Rolling, ordered	Rolling, parallel
Use case	Databases, queues	Stateless apps

Reclaim Policies

What happens to storage when PVC is deleted.

Policy	Behavior
Delete	PV and disk deleted with PVC (default)
Retain	PV released, disk kept for manual recovery

Protect Important Data

yaml

# StorageClass with Retain policy
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: retain-storage
provisioner: pd.csi.storage.gke.io
reclaimPolicy: Retain  # Keep data after PVC deletion

Volume Expansion

Expand volumes without downtime.

Expand a Volume

bash

# Edit PVC to increase size
kubectl patch pvc my-pvc -p '{"spec":{"resources":{"requests":{"storage":"50Gi"}}}}'

Requirements:

StorageClass must have allowVolumeExpansion: true
Can only increase size, not decrease
Filesystem resize happens when Pod remounts

Filestore (NFS)

For ReadWriteMany access across multiple Pods.

Filestore StorageClass

yaml

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: filestore
provisioner: filestore.csi.storage.gke.io
parameters:
  tier: standard
  network: default
volumeBindingMode: Immediate
allowVolumeExpansion: true

Filestore PVC

yaml

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: shared-storage
spec:
  accessModes:
    - ReadWriteMany
  storageClassName: filestore
  resources:
    requests:
      storage: 1Ti  # Minimum for standard tier

Volume Snapshots

Point-in-time backup of persistent volumes.

Create a Snapshot

yaml

apiVersion: snapshot.storage.k8s.io/v1
kind: VolumeSnapshot
metadata:
  name: my-snapshot
spec:
  volumeSnapshotClassName: csi-pd-snapshot-class
  source:
    persistentVolumeClaimName: my-pvc

Restore from Snapshot

yaml

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: restored-pvc
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: standard-rwo
  resources:
    requests:
      storage: 30Gi
  dataSource:
    name: my-snapshot
    kind: VolumeSnapshot
    apiGroup: snapshot.storage.k8s.io

Best Practices

Storage Selection Guide

Recommendation	Description
Use WaitForFirstConsumer	Provision in same zone as Pod
Set resource requests	Always specify storage size
Use StatefulSets	For stateful applications
Enable volume expansion	Allow growth without recreation
Use Retain for production	Prevent accidental data loss
Backup with snapshots	Regular point-in-time backups

Quick Reference

Common Commands

bash

# List storage classes
kubectl get storageclass

# List PVCs
kubectl get pvc -A

# List PVs
kubectl get pv

# Describe PVC
kubectl describe pvc my-pvc

# Check volume attachment
kubectl get volumeattachment

Troubleshooting

Issue	Solution
PVC Pending	Check StorageClass exists, quota available
Pod stuck ContainerCreating	PVC not bound, check events
Mount failed	Check node zone matches disk zone
Resize not working	StorageClass needs allowVolumeExpansion

Last updated: December 2025

GKE Storage Guide ​

Storage Overview ​

Key Storage Concepts ​

PersistentVolumes and Claims ​

How Dynamic Provisioning Works ​

Create a PersistentVolumeClaim ​

Use PVC in a Pod ​

StorageClasses ​

Default StorageClasses in GKE ​

Custom StorageClass ​

StorageClass Parameters ​

Access Modes ​

Regional Persistent Disks ​

Regional PD StorageClass ​

Regional PD Benefits ​

StatefulSets ​

StatefulSet Example ​

StatefulSet vs Deployment ​

Reclaim Policies ​

Protect Important Data ​

Volume Expansion ​

Expand a Volume ​

Filestore (NFS) ​

Filestore StorageClass ​

Filestore PVC ​

Volume Snapshots ​

Create a Snapshot ​

Restore from Snapshot ​

Best Practices ​

Storage Selection Guide ​

Quick Reference ​

Common Commands ​

Troubleshooting ​

GKE Storage Guide

Storage Overview

Key Storage Concepts

PersistentVolumes and Claims

How Dynamic Provisioning Works

Create a PersistentVolumeClaim

Use PVC in a Pod

StorageClasses

Default StorageClasses in GKE

Custom StorageClass

StorageClass Parameters

Access Modes

Regional Persistent Disks

Regional PD StorageClass

Regional PD Benefits

StatefulSets

StatefulSet Example

StatefulSet vs Deployment

Reclaim Policies

Protect Important Data

Volume Expansion

Expand a Volume

Filestore (NFS)

Filestore StorageClass

Filestore PVC

Volume Snapshots

Create a Snapshot

Restore from Snapshot

Best Practices

Storage Selection Guide

Quick Reference

Common Commands

Troubleshooting