Kubernetes CSI Drivers: Storage Plugins Explained

💡 Quick Answer: Understand Container Storage Interface (CSI) drivers in Kubernetes. Install and configure CSI drivers for AWS EBS, Azure Disk, NFS, and Ceph storage backends.

The Problem

Engineers frequently search for this topic but find scattered, incomplete guides. This recipe provides a comprehensive, production-ready reference.

The Solution

What Is CSI?

Container Storage Interface (CSI) is the standard for exposing storage systems to Kubernetes. Each storage backend has its own CSI driver.

Popular CSI Drivers

Install NFS CSI Driver

helm repo add csi-driver-nfs https://raw.githubusercontent.com/kubernetes-csi/csi-driver-nfs/master/charts
helm install csi-driver-nfs csi-driver-nfs/csi-driver-nfs --namespace kube-system

# StorageClass using NFS CSI
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: nfs-csi
provisioner: nfs.csi.k8s.io
parameters:
  server: nfs.example.com
  share: /exports/k8s
reclaimPolicy: Delete
volumeBindingMode: Immediate
mountOptions:
  - nfsvers=4.1

CSI Volume Snapshots

# Create snapshot
apiVersion: snapshot.storage.k8s.io/v1
kind: VolumeSnapshot
metadata:
  name: db-snapshot
spec:
  volumeSnapshotClassName: csi-snapclass
  source:
    persistentVolumeClaimName: postgres-data
---
# Restore from snapshot
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: postgres-restored
spec:
  dataSource:
    name: db-snapshot
    kind: VolumeSnapshot
    apiGroup: snapshot.storage.k8s.io
  accessModes: [ReadWriteOnce]
  resources:
    requests:
      storage: 50Gi

graph TD
    A[PVC request] --> B[StorageClass: provisioner=nfs.csi.k8s.io]
    B --> C[CSI Driver]
    C --> D[NFS Server creates share]
    D --> E[PV created + bound]
    E --> F[Pod mounts volume]

Frequently Asked Questions

In-tree vs CSI drivers?

In-tree drivers (built into Kubernetes) are deprecated. All new storage integrations use CSI. Existing in-tree drivers are being migrated to CSI.

Best Practices

• Start with the simplest approach that solves your problem
• Test thoroughly in staging before production
• Monitor and iterate based on real metrics
• Document decisions for your team

Key Takeaways

• This is essential Kubernetes operational knowledge
• Production-readiness requires proper configuration and monitoring
• Use kubectl describe and logs for troubleshooting
• Automate where possible to reduce human error