A Developer’s Guide to Kubernetes Persistent Storage
Last Updated on June 12, 2025
Last Updated on June 12, 2025
Quick Summary
In this article, you will explore how Kubernetes persistent storage works and why it is essential for running stateful applications. It covers the core components like PersistentVolumes, PersistentVolumeClaims, and StorageClasses. You will also learn about five common storage challenges and discover best practices to ensure reliable, secure, and efficient storage management in Kubernetes environments.
Table of Contents
Containers are lightweight, fast, and ideal for running modern applications. But by default, they are ephemeral. That means they lose data when they stop or restart. This becomes a major issue for stateful applications like databases or content management systems that rely on data continuity. Kubernetes solves this problem with a strong approach to persistent storage.
Kubernetes persistent storage allows containers to store and retrieve data even after restarts or rescheduling. It helps teams deploy applications that require consistent data access. In this guide, you will learn how Kubernetes handles storage, how to set it up, and how to use it effectively for real-world needs.
Kubernetes persistent storage is a way to store data in a durable and reusable format. When a pod restarts, the storage remains intact. Unlike temporary storage, persistent storage keeps data available across sessions.
Kubernetes uses a set of objects to manage storage:
These tools give developers full control over how they store and manage data across pods.
Stateful applications need reliable access to data. When a container restarts without persistent storage, all the stored data gets lost. This is acceptable for some services, but not for:
Using Kubernetes persistent storage allows you to run these workloads with confidence. It also brings flexibility, as you can mount volumes from local disks, cloud services, or networked file systems.
Kubernetes connects your application to storage using a two-step process. First, it defines the storage. Then, it connects the application to that storage.
A PV is a storage resource in your cluster. It can come from a local disk or a cloud storage service like AWS EBS, Azure Disk, or Google Persistent Disk.
A PVC asks for specific storage. The request includes size, access mode, and sometimes the storage class. Once Kubernetes finds a matching PV, it binds the PVC to it.
You can now mount the PVC inside any pod that needs it. This gives your application access to storage that survives restarts.
Kubernetes supports multiple storage options based on your needs:
Kubernetes offers two ways to provide storage to applications.
You manually create PersistentVolumes before claiming them. This requires careful planning and ongoing storage management.
Kubernetes automatically creates storage when a PVC requests it. This is possible through StorageClass. You define the type of storage you need, and Kubernetes provisions it on demand.
Dynamic provisioning simplifies deployment and scales better.
Following best practices helps you manage persistent storage more effectively, avoid risks, and ensure high availability.
Use StorageClasses to automate volume provisioning. Create different classes for standard disks, SSDs, or encrypted storage. This lets your team select the right performance or security level for each workload.
Kubernetes offers different access modes:
Choose the right mode based on your application’s requirements. For example, RWX is essential for shared file systems.
Track disk usage and storage performance. Set up alerts to detect volume saturation early. Monitoring helps prevent crashes due to full volumes and ensures smooth operations.
Take regular snapshots of your persistent volumes, especially before major updates or changes. Snapshots provide fast recovery and protect against data loss.
Control who can create, delete, or access storage resources. Use Kubernetes RBAC policies to protect sensitive volumes from unauthorized access.
Always specify the storage size in PVCs. Set upper limits to prevent a single workload from using all available storage. This helps in fair resource distribution across the cluster.
Use encrypted volumes for workloads that handle sensitive data. Cloud providers offer encrypted options for Kubernetes storage, which improve security without performance loss.
Even though Kubernetes simplifies storage management, users may face real-world challenges if they don’t follow a solid storage strategy. Here are five key challenges, each explained in detail:
Deleting a PVC without proper backup can permanently remove data, especially when the underlying StorageClass uses a Delete reclaim policy. Many teams face unexpected data loss when they clean up resources without a backup strategy.
Solution: Always use volume snapshots or external backups before deleting storage claims.
Some workloads need high IOPS (input/output operations per second), while others can work on standard disks. Using slow storage for high-performance applications leads to delays and unstable performance.
Solution: Match your application’s needs with the right StorageClass. Use SSD-backed storage for databases or logging systems.
Certain volumes, like AWS EBS, work only within a single availability zone. If your application scales across zones, storage access may break.
Solution: Use storage solutions that support multi-zone or RWX access modes like NFS or cloud-native file systems such as Amazon EFS or Google Filestore.
Sometimes, deleting pods or PVCs doesn’t release the storage volumes, especially in manually provisioned environments. These orphaned volumes continue consuming resources and increase costs.
Solution: Regularly audit PVs in Released or Failed state and clean up unused volumes.
StatefulSets help run applications like databases in Kubernetes. However, managing their volumes can be tricky. Each pod gets its own volume, and if you scale down without caution, Kubernetes doesn’t automatically delete volumes.
Solution: Document your scaling and deletion processes clearly. Use labels and annotations to track volumes and automate cleanup.
Here’s a simple YAML setup to use persistent storage:
apiVersion: storage.k8s.io/v1 kind: StorageClass metadata: name: standard provisioner: kubernetes.io/aws-ebs parameters: type: gp2
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: my-pvc
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 5Gi
storageClassName: standard
apiVersion: v1
kind: Pod
metadata:
name: storage-pod
spec:
containers:
- name: app
image: nginx
volumeMounts:
- mountPath: /usr/share/nginx/html
name: storage
volumes:
- name: storage
persistentVolumeClaim:
claimName: my-pvc
This setup gives your pod access to a 5GB persistent volume. The pod stores all HTML content on that volume.
Kubernetes persistent storage is essential for running reliable, stateful workloads. It ensures that important data remains available, even when containers restart or move between nodes. By using Persistent Volumes, Persistent Volume Claims, and Storage Classes, developers can build flexible and scalable applications that manage data easily.
When Kubernetes developers follow best practices and choose the right storage backend, they avoid common pitfalls and gain strong control over data operations. As Kubernetes adoption grows, storage becomes more critical than ever. Integrating persistent storage with tools like volume snapshots and backup solutions enhances application resilience. Organizations also benefit by combining persistent storage with modern Kubernetes storage best practices and robust support from Kubernetes volumes.