EKS Storage

Last Updated: July 3, 2026

When running applications on Amazon EKS, there are various storage options for storing and managing data. This document covers the basic concepts of EKS storage and how to use Amazon EBS (Elastic Block Store) and Amazon EFS (Elastic File System).

Table of Contents

1. Kubernetes Storage Basic Concepts
2. Amazon EKS Storage Options Overview
3. Storage with Amazon EBS
4. Storage with Amazon EFS
5. Storage Classes and Dynamic Provisioning

Kubernetes Storage Basic Concepts

Let's first understand the key concepts for managing storage in Kubernetes.

Volume

A volume is a directory that can be mounted to containers within a pod, and data persists even if the container restarts. The lifetime of a volume is the same as the pod's lifetime, and when the pod is deleted, the volume is also deleted.

Persistent Volume (PV)

A persistent volume is a piece of cluster storage that is provisioned by an administrator or dynamically provisioned through a storage class. PVs have a lifecycle independent of pods, and PVs persist even when pods are deleted.

Persistent Volume Claim (PVC)

A persistent volume claim is a user's request for storage. A PVC requests storage with a specific size and access mode, and this request is bound to an appropriate PV.

StorageClass

A storage class describes the "class" of storage offered by the administrator. Using storage classes allows PVs to be dynamically provisioned when PVCs are created.

Access Modes

Kubernetes supports the following access modes:

• ReadWriteOnce (RWO): Can be mounted as read/write by a single node
• ReadOnlyMany (ROX): Can be mounted as read-only by many nodes
• ReadWriteMany (RWX): Can be mounted as read/write by many nodes
• ReadWriteOncePod (RWOP): Can be mounted as read/write by only a single pod (Kubernetes 1.22+)

Amazon EKS Storage Options Overview

In Amazon EKS, you can leverage various AWS storage services to provide storage for containerized applications.

Main Storage Options

1. Amazon EBS (Elastic Block Store)
   • Block storage, mountable to a single node (RWO)
   • High-performance, durable block storage
   • Suitable for databases, stateful applications
2. Amazon EFS (Elastic File System)
   • Fully managed NFS file system
   • Can be mounted simultaneously from multiple nodes (RWX)
   • Suitable for workloads requiring shared file systems
3. Amazon FSx for Lustre
   • High-performance file system
   • Suitable for machine learning, HPC, big data analytics
   • Can be mounted simultaneously from multiple nodes (RWX)
4. Amazon S3 (Simple Storage Service)
   • Object storage
   • Cannot be directly mounted as a volume, but accessible through S3 API
   • Suitable for large-scale data storage
5. EC2 Instance Store (Local NVMe)
   • Ephemeral local NVMe storage physically attached to the EC2 instance, offering very low latency
   • The EC2 Instance Store CSI Driver reached general availability (GA) as an Amazon EKS add-on in May 2026, so it can now be installed and managed as a standard add-on from the EKS Console/CLI (previously required manual installation via community manifests). The driver automatically manages volume lifecycle, reducing operational overhead
   • Suitable for AI/ML ephemeral data processing, Spark/Hadoop local caching, high-throughput log processing, and database cache tiers
   • Cost: the driver itself is free; you only pay for the underlying EC2 instance that includes instance store (source)

Storage Options Comparison

Storage Option	Type	Access Mode	Performance	Use Cases
Amazon EBS	Block	RWO	High	Databases, stateful applications
Amazon EFS	File	RWX	Medium	Shared files, web servers, CMS
FSx for Lustre	File	RWX	Very High	HPC, ML training, big data
Amazon S3	Object	API Access	Medium	Backup, archive, static content
EC2 Instance Store	Block (local NVMe)	RWO, ephemeral	Very High (ultra-low latency)	AI/ML ephemeral data, local caching, high-throughput log processing

Storage with Amazon EBS

Amazon EBS provides block-level storage volumes that can be attached to EC2 instances. In EKS, you can mount EBS volumes to Kubernetes pods through the EBS CSI (Container Storage Interface) driver.

Installing EBS CSI Driver

To use EBS volumes in EKS, you need to install the EBS CSI driver. This driver is provided as an Amazon EKS add-on.

# Install EBS CSI driver
eksctl create addon --name aws-ebs-csi-driver --cluster my-cluster --version latest

# Or using AWS CLI
aws eks create-addon --cluster-name my-cluster --addon-name aws-ebs-csi-driver --addon-version latest

Creating EBS Storage Class

Create a storage class for dynamic provisioning of EBS volumes. Here we use the gp3 volume type.

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: ebs-gp3
provisioner: ebs.csi.aws.com
volumeBindingMode: WaitForFirstConsumer
parameters:
  type: gp3
  encrypted: "true"
  fsType: ext4

Creating Persistent Volume Claim (PVC)

Create a PVC to be used by your application.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: ebs-claim
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: ebs-gp3
  resources:
    requests:
      storage: 10Gi

Using PVC in a Pod

Mount the created PVC in a pod.

apiVersion: v1
kind: Pod
metadata:
  name: app-with-ebs
spec:
  containers:
  - name: app
    image: nginx
    volumeMounts:
    - mountPath: "/data"
      name: ebs-volume
  volumes:
  - name: ebs-volume
    persistentVolumeClaim:
      claimName: ebs-claim

EBS Volume Snapshots

You can create snapshots of EBS volumes to backup data.

apiVersion: snapshot.storage.k8s.io/v1
kind: VolumeSnapshot
metadata:
  name: ebs-snapshot
spec:
  volumeSnapshotClassName: csi-aws-vsc
  source:
    persistentVolumeClaimName: ebs-claim

EBS Volume Expansion

You can expand the size of EBS volumes as needed.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: ebs-claim
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: ebs-gp3
  resources:
    requests:
      storage: 20Gi  # Expanded from 10Gi to 20Gi

EBS Volume Types and Performance

Amazon EBS provides various volume types:

Volume Type	Description	Use Cases
gp3	General Purpose SSD	Suitable for most workloads, cost-effective
io2	Provisioned IOPS SSD	High-performance databases
st1	Throughput Optimized HDD	Big data, log processing
sc1	Cold HDD	Infrequently accessed data

For EKS, the gp3 volume type is recommended. gp3 is cost-effective while providing consistent performance.

Storage with Amazon EFS

Amazon EFS is a fully managed NFS file system that can be accessed simultaneously from multiple EC2 instances. In EKS, you can mount EFS file systems to multiple pods simultaneously through the EFS CSI driver.

Installing EFS CSI Driver

To use EFS in EKS, you need to install the EFS CSI driver.

# Install EFS CSI driver
eksctl create addon --name aws-efs-csi-driver --cluster my-cluster --version latest

# Or using AWS CLI
aws eks create-addon --cluster-name my-cluster --addon-name aws-efs-csi-driver --addon-version latest

Creating EFS File System

Create an EFS file system using AWS Management Console, AWS CLI, or AWS CloudFormation.

# Create EFS file system using AWS CLI
aws efs create-file-system \
  --performance-mode generalPurpose \
  --throughput-mode bursting \
  --encrypted \
  --tags Key=Name,Value=MyEFSFileSystem

# Save file system ID
EFS_FS_ID=$(aws efs describe-file-systems --query "FileSystems[?Name=='MyEFSFileSystem'].FileSystemId" --output text)

# Get EKS cluster VPC ID
VPC_ID=$(aws eks describe-cluster --name my-cluster --query "cluster.resourcesVpcConfig.vpcId" --output text)

# Create security group
aws ec2 create-security-group \
  --group-name MyEFSSecurityGroup \
  --description "Security group for EFS mount targets" \
  --vpc-id $VPC_ID

SG_ID=$(aws ec2 describe-security-groups \
  --filters Name=group-name,Values=MyEFSSecurityGroup \
  --query "SecurityGroups[0].GroupId" --output text)

# Allow NFS traffic
aws ec2 authorize-security-group-ingress \
  --group-id $SG_ID \
  --protocol tcp \
  --port 2049 \
  --cidr 10.0.0.0/16

# Get subnet IDs
SUBNET_IDS=$(aws ec2 describe-subnets \
  --filters "Name=vpc-id,Values=$VPC_ID" \
  --query "Subnets[*].SubnetId" --output text)

# Create mount target in each subnet
for SUBNET_ID in $SUBNET_IDS; do
  aws efs create-mount-target \
    --file-system-id $EFS_FS_ID \
    --subnet-id $SUBNET_ID \
    --security-groups $SG_ID
done

Creating EFS Storage Class

Create a storage class for using EFS.

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: efs-sc
provisioner: efs.csi.aws.com
parameters:
  provisioningMode: efs-ap
  fileSystemId: fs-0123456789abcdef0  # Created EFS file system ID
  directoryPerms: "700"

Creating Persistent Volume Claim (PVC)

Create a PVC for using EFS.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: efs-claim
spec:
  accessModes:
    - ReadWriteMany  # Can read/write simultaneously from multiple nodes
  storageClassName: efs-sc
  resources:
    requests:
      storage: 5Gi

Using EFS PVC in a Pod

Mount the created PVC in a pod.

apiVersion: v1
kind: Pod
metadata:
  name: app-with-efs
spec:
  containers:
  - name: app
    image: nginx
    volumeMounts:
    - mountPath: "/shared-data"
      name: efs-volume
  volumes:
  - name: efs-volume
    persistentVolumeClaim:
      claimName: efs-claim

EFS Access Points

Using EFS access points allows you to restrict access to specific directories and set user and group permissions.

apiVersion: v1
kind: PersistentVolume
metadata:
  name: efs-pv
spec:
  capacity:
    storage: 5Gi
  volumeMode: Filesystem
  accessModes:
    - ReadWriteMany
  persistentVolumeReclaimPolicy: Retain
  storageClassName: efs-sc
  csi:
    driver: efs.csi.aws.com
    volumeHandle: fs-0123456789abcdef0::fsap-0123456789abcdef0
    # volumeHandle format: {EFS file system ID}::{EFS access point ID}

EFS Performance Modes and Throughput Modes

Amazon EFS provides two performance modes and three throughput modes:

Performance Modes:

• General Purpose: Recommended for most workloads
• Max I/O: Suitable for workloads requiring high parallel processing

Throughput Modes:

• Bursting: Default mode, provides burst credits based on file system size
• Provisioned: Use when consistent throughput is needed
• Elastic: Automatically adjusts throughput based on workload (recommended)

Storage Classes and Dynamic Provisioning

Using Kubernetes storage classes allows persistent volumes to be dynamically provisioned. In EKS, you can configure storage classes for various AWS storage services.

Volume Binding Modes

The volumeBindingMode field in a storage class determines how PVs are bound when PVCs are created:

• Immediate: Provisions and binds PV immediately when PVC is created.
• WaitForFirstConsumer: Delays PV provisioning until a pod tries to use the PVC.

For node-local storage like EBS, it is recommended to use WaitForFirstConsumer. This ensures the volume is created in the same availability zone as the node where the pod is scheduled.

Setting Default Storage Class

Setting a specific storage class as default allows that storage class to be used even when the storage class is not specified in the PVC.

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: ebs-gp3
  annotations:
    storageclass.kubernetes.io/is-default-class: "true"
provisioner: ebs.csi.aws.com
volumeBindingMode: WaitForFirstConsumer
parameters:
  type: gp3
  encrypted: "true"

Storage Class Examples

1. EBS gp3 Storage Class

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: ebs-gp3
provisioner: ebs.csi.aws.com
volumeBindingMode: WaitForFirstConsumer
parameters:
  type: gp3
  encrypted: "true"
  iops: "3000"
  throughput: "125"

2. EFS Storage Class

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: efs-sc
provisioner: efs.csi.aws.com
parameters:
  provisioningMode: efs-ap
  fileSystemId: fs-0123456789abcdef0
  directoryPerms: "700"

3. FSx for Lustre Storage Class

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: fsx-lustre
provisioner: fsx.csi.aws.com
parameters:
  subnetId: subnet-0123456789abcdef0
  securityGroupIds: sg-0123456789abcdef0
  deploymentType: SCRATCH_2
  automaticBackupRetentionDays: "0"
  dailyAutomaticBackupStartTime: "00:00"
  perUnitStorageThroughput: "200"
  dataCompressionType: "NONE"

Reclaim Policies

The reclaim policy of a persistent volume determines how the PV and its data are handled when the PVC is deleted:

• Delete: When PVC is deleted, the PV and its data are also deleted.
• Retain: When PVC is deleted, the PV and data are retained. Administrator must manually clean up.
• Recycle: Deprecated policy, use dynamic provisioning and storage classes instead.

You can set the reclaim policy using the persistentVolumeReclaimPolicy field in the storage class:

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: ebs-gp3-retain
provisioner: ebs.csi.aws.com
volumeBindingMode: WaitForFirstConsumer
reclaimPolicy: Retain
parameters:
  type: gp3
  encrypted: "true"

Conclusion

In Amazon EKS, you can configure storage solutions that meet your application requirements using various storage options. This document covered basic concepts and configuration methods focusing on EBS and EFS. The next document will cover advanced storage configurations using FSx for Lustre and S3.

Quiz

To test what you've learned in this chapter, try the topic quiz.