📝 Docker Volumes Explained: Persisting Data in DevOps Containers

Devops ankit sharma November 29, 2025 2 mins read

Learn how Docker volumes work, why they matter, and how to manage persistent data across container lifecycles.

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1. Introduction

Containers are ephemeral by default—once a container stops or is removed, its internal data disappears. Docker volumes solve this challenge by providing persistent storage that survives restarts, rebuilds, and upgrades. For stateful workloads, volumes are indispensable.

2. What Is a Docker Volume?

A Docker volume is a directory stored outside the container’s writable layer.

Key benefits:

  • Managed directly by Docker

  • Mounted into containers at runtime

  • Ideal for databases, logs, user uploads, and long-term configs

Volumes ensure your application data isn’t tied to the lifecycle of a single container.

3. Creating and Using Volumes

Create a volume

 
docker volume create mydata

Use it inside a container

 
docker run -v mydata:/app/data nginx

Inspect a volume

 
docker volume inspect mydata

List all volumes

 
docker volume ls

Remove a volume

 
docker volume rm mydata

4. Bind Mounts vs Named Volumes

Type Path Location Use Case
Named Volume Managed by Docker Recommended for most environments
Bind Mount Host file system path Great for local development

  • Named Volumes → more secure, portable, and stable

  • Bind Mounts → direct file access during development

5. Best Practices

  • Use named volumes for production workloads

  • Avoid storing sensitive data in containers

  • Backup volumes for databases and critical services

  • Use volume drivers for external/cloud storage (NFS, S3, EFS)

  • Remove unused volumes to prevent disk bloat

6. Volumes in docker-compose.yml

Example of persistent PostgreSQL data storage:

 
version: '3' services: db: image: postgres volumes: - pgdata:/var/lib/postgresql/data volumes: pgdata:

7. Conclusion

Docker volumes are essential for building resilient, stateful DevOps environments. They ensure your data persists across container lifecycles while enabling scalable, maintainable infrastructure. Mastering Docker volumes will prepare you for more advanced storage strategies in containerized environments.

Tomorrow’s post will explore Dockerfile Security and Vulnerability Scanning—stay tuned!

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ankit sharma

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