This page explains how to install a Container Storage Interface (CSI) storagedriver on Google Kubernetes Engine (GKE) Standard clusters. This pagedoesn't apply to GKE Autopilot clusters, whichautomatically use theCompute Engine persistent disk CSI driver.

If you are using theCompute Engine persistent disk CSI driver in yourStandard cluster, we recommendautomatically deploying the driverto reduce your management overhead.

Overview

CSI is an open standard API that enables Kubernetes to expose arbitrary storagesystems to containerized workloads. Kubernetes volumes are managed byvendor-specific storage drivers, which have historically beencompiled into Kubernetes binaries.Previously, you could not use a storage driver that was not included withKubernetes. Installing a CSI driver adds support for a storage system that isnot natively supported by Kubernetes. Also, CSI enables the use of modernstorage features, such as snapshots and resizing.

Other storage vendors develop their own CSI drivers, and they are responsible forproviding installation instructions. In simple cases, installation might onlyinvolve deploying manifests to your clusters. See the list ofCSIdrivers in theCSI documentation.

kubectl get csinodes \-o jsonpath='{range .items[*]} {.metadata.name}{": "} {range .spec.drivers[*]} {.name}{"\n"} {end}{end}'

kubectl get nodes \-o jsonpath='{.items[*].metadata.annotations.csi\.volume\.kubernetes\.io\/nodeid}'

1. Create a KubernetesStorageClass that references the driver in itsprovisioner field, if a StorageClass isnot created for you as part of driver installation. Some CSI drivers deploya StorageClass when you install them.

2. To provision storage, you can either:

   • Reference the StorageClass in thevolumeClaimTemplates specification foraStatefulSet object.
   • Set it as the cluster's default StorageClass.

Considerations for StorageClasses backed by a CSI driver

When you create a StorageClass, consider the following:

• CSI driver documentation should include thedriver-specific parameters that you provide to your StorageClass, including the provisioner name.
• You should name the StorageClass after its properties, rather than after thename of the specific driver or appliance behind it. Naming the StorageClassafter its properties allows you to create StorageClasses with the same nameacross multiple clusters and environments, and allows your applications to getstorage with the same properties across clusters.

Example: Reference StorageClass in a StatefulSet

The following example models how to define a CSI driver in a StorageClass, andthen reference the StorageClass in aStatefulSet workload. The example assumes the driver has already been installed to thecluster.

The following is a simple StorageClass namedpremium-rwo that uses a fictionalCSI driver,csi.example.com, as its provisioner:

# fast-sc.yamlapiVersion:storage.k8s.io/v1kind:StorageClassmetadata:name:premium-rwoprovisioner:csi.example.com# CSI driverparameters:# You provide vendor-specific parameters to this specificationtype:example-parameter# Be sure to follow the vendor's instructionsdatastore:my-datastorereclaimPolicy:RetainallowVolumeExpansion:true

You reference the StorageClass in a StatefulSet'svolumeClaimTemplatesspecification.

When you reference a StorageClass in a StatefulSet'svolumeClaimTemplatesspecification, Kubernetes provides stable storage using PersistentVolumes.Kubernetes calls the provisioner defined in the StorageClass to create a newstorage volume. In this case, Kubernetes calls the fictionalcsi.example.comprovider, which calls out to the provider's API, to create a volume. After thevolume is provisioned, Kubernetes automatically creates a PersistentVolume torepresent the storage.

Here is a simple StatefulSet that references the StorageClass:

# statefulset.yamlapiVersion:apps/v1kind:StatefulSetmetadata:name:webspec:replicas:2selector:matchLabels:app:nginxtemplate:metadata:labels:app:nginxspec:containers:-name:nginximage:registry.k8s.io/nginx-slim:0.8volumeMounts:-name:wwwmountPath:/usr/share/nginx/htmlvolumeClaimTemplates:# This is the specification in which you reference the StorageClass-metadata:name:wwwspec:accessModes:["ReadWriteOnce"]resources:requests:storage:1GistorageClassName:premium-rwo# This field references the existing StorageClass

What's next

• Learn more about GKEstorage concepts.