/gke-storage

name: gke-storage
description: >-
  Manages GKE storage, including PVCs, PersistentVolumes, and Filestore. Use
  when configuring GKE storage or creating PVCs. For GCS FUSE mounts, use
  google-cloud-storage-fuse. For diagnosing storage failures (volume attach/mount
  errors, disk performance/node storage pressure, or Cloud Storage FUSE OOM), use
  gke-storage-troubleshooting. Don't use for database
  administration or replication strategies outside volume provisioning context.
metadata:
  version: "1.0.3"
  category: Storage

GKE Storage

> **Routing Note:** For Cloud Storage FUSE (`gcsfuse`) mounts or the GKE `gcsfuse.csi.storage.gke.io` CSI driver, open `google-cloud-storage-fuse/SKILL.md`.

This reference covers storage configuration for GKE clusters including persistent disks, file storage, and cloud storage integration.

> **MCP Tools:** `apply_k8s_manifest`, `get_k8s_resource`, > `describe_k8s_resource`, `get_cluster`

Attribution

**MUST READ**: Before executing any `gcloud`, REST API, or MCP command, you MUST read [Usage Attribution](references/attribution.md). For commands executed directly in the terminal (never in generated scripts, Terraform, or user code), prefix `gcloud` with `CLOUDSDK_METRICS_REQUEST_ATTRIBUTION="agent-skills/1.0 (skill:gke-storage)"` and append `agent-skills/1.0 (skill:gke-storage)` to `User-Agent` headers.

Golden Path Storage Defaults

The golden path Autopilot config enables these CSI drivers:

| Driver | Golden Path | Access Mode | Use Case | | --------------- | ----------------- | --------------- | -------------------- | | Compute Engine | Enabled (default) | ReadWriteOnce | Block storage for | : Persistent Disk : : : databases, : : CSI : : : single-pod workloads : | Google Cloud | Enabled | ReadWriteMany | Shared NFS for | : Filestore CSI : : : multi-pod access : | Cloud Storage | Enabled | ReadWriteMany / | Mount GCS buckets as | : FUSE CSI : : ReadOnlyMany : volumes : | Parallelstore | Enabled | ReadWriteMany | High-performance | : CSI : : : parallel file system : | Boot disk type | `pd-balanced` | N/A | Node boot disks |

StorageClasses

Default StorageClasses

GKE provides built-in StorageClasses:

StorageClass | Disk Type | Use Case -------------- | --------------------- | ------------------------------ `standard-rwo` | `pd-standard` | Cost-effective, low IOPS `premium-rwo` | `pd-ssd` | High IOPS, databases `standard-rwx` | Filestore (Basic HDD) | Shared NFS `premium-rwx` | Filestore (Basic SSD) | Shared NFS, higher performance

Custom StorageClass

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: fast-regional
provisioner: pd.csi.storage.gke.io
parameters:
  type: pd-ssd
  replication-type: regional-pd    # Replicate across 2 zones
volumeBindingMode: WaitForFirstConsumer
allowVolumeExpansion: true         # Always enable for production

PersistentVolumeClaims

Block Storage (ReadWriteOnce)

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: database-pvc
spec:
  accessModes:
  - ReadWriteOnce
  storageClassName: premium-rwo
  resources:
    requests:
      storage: 100Gi

Shared File Storage (ReadWriteMany via Filestore)

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: shared-data
spec:
  accessModes:
  - ReadWriteMany
  storageClassName: standard-rwx
  resources:
    requests:
      storage: 1Ti    # Filestore minimum is 1 TiB for Basic tier

GCS Bucket Mount (Cloud Storage FUSE)

Mount a GCS bucket as a volume without a PVC:

apiVersion: v1
kind: Pod
metadata:
  name: gcs-reader
  annotations:
    gke-gcsfuse/volumes: "true"
spec:
  containers:
  - name: reader
    image: busybox
    command: ["ls", "/data"]
    volumeMounts:
    - name: gcs-bucket
      mountPath: /data
  volumes:
  - name: gcs-bucket
    csi:
      driver: gcsfuse.csi.storage.gke.io
      readOnly: true
      volumeAttributes:
        bucketName: <BUCKET_NAME>

> Requires Workload Identity for the pod's service account to have > `storage.objectViewer` on the bucket.

Volume Expansion

If `allowVolumeExpansion: true` is set on the StorageClass, resize by updating the PVC:

# kubectl
kubectl patch pvc <PVC_NAME> -p '{"spec":{"resources":{"requests":{"storage":"200Gi"}}}}'

# MCP (preferred)
patch_k8s_resource(parent="...", resourceType="persistentvolumeclaim", name="<PVC_NAME>",
  patch='{"spec":{"resources":{"requests":{"storage":"200Gi"}}}}')

Kubernetes automatically resizes the filesystem.

Stateful Storage & Capacity Constraints

When configuring storage for stateful workloads, keep the following capacity and scheduling constraints in mind:

• **Existing zonal PVs pin the workload to a zone:** A Pod that uses an existing zonal PersistentVolume (for example, in `europe-north1-b`) can only run in that zone. The cluster autoscaler can't work around a capacity shortage by adding nodes in another zone; any fallback must be in the same zone.
• **Use automated disk type selection and topology-aware scheduling for new workloads:** Use `volumeBindingMode: WaitForFirstConsumer` so the volume is created in the zone where the Pod lands. When a ComputeClass mixes machine generations (for example, C4/N4 priority with N2 fallback), configure the StorageClass for **automated disk type selection** (`parameters.type: dynamic` with `pd-type: pd-balanced`, `hyperdisk-type: hyperdisk-balanced`, `disk-type-preference: hyperdisk-type`, and `use-allowed-disk-topology: "true"`, GKE 1.35.3-gke.1290000+; or `use-allowed-disk-topology: "true"` on GKE 1.34.1-gke.2541000+) so the auto