One of the biggest challenges in containerized environments is ensuring data persistence — that is, retaining data even after a container stops or is removed. By default, Docker containers are ephemeral, meaning data stored inside them is lost unless explicitly persisted.

Docker volumes solve this problem by providing a way to store data outside of the container’s writable layer, making it durable and shareable. In this post, we’ll explore what Docker volumes are, how they differ from bind mounts, how to use and manage them, and best practices for persistent storage in Dockerized applications.

What Are Docker Volumes?

A Docker volume is a directory managed by Docker and stored on the host file system, but outside of the container’s UFS (Union File System). Volumes are the preferred mechanism for persisting data in Docker.

Benefits:

  • Decouples storage from containers
  • Survives container restarts and removals
  • Easier to back up and restore
  • Works across container restarts and deployments
  • Can be shared between multiple containers

Volume vs Bind Mount

Feature Volume Bind Mount
Managed by Docker ✅ Yes ❌ No
Path location /var/lib/docker/volumes/ Anywhere on host file system
Backups Easier with docker volume commands Manual
Use cases Production workloads Development/debugging
Portability High Low

Use volumes for production and bind mounts for local dev/debug.

Creating and Using Docker Volumes

1. Create a Volume
docker volume create my_data_volume
2. Use Volume in a Container
docker run -d \
--name postgres-db \
-v my_data_volume:/var/lib/postgresql/data \
postgres

This ensures the database files persist even if the container is deleted.

Inspecting and Managing Volumes

List Volumes
docker volume ls
Inspect Volume Metadata
docker volume inspect my_data_volume

This provides mountpoint info, labels, and driver info.

Remove a Volume
docker volume rm my_data_volume

Note: You cannot remove a volume if it’s still in use by a container.

Anonymous vs Named Volumes

  • Named Volumes: Explicitly defined and easier to reuse
    Example: -v my_volume:/data

  • Anonymous Volumes: Auto-generated by Docker, harder to manage
    Example: -v /data

View anonymous volumes:

docker volume ls -qf dangling=true

Clean them up with:

docker volume prune

Docker Compose and Volumes

In docker-compose.yml:

services:
redis:
image: redis
volumes:
- redis_data:/data

volumes:
redis_data:

Compose will automatically create and manage the named volume redis_data.

Backing Up and Restoring Docker Volumes

Backup:

docker run --rm \
-v my_data_volume:/data \
-v $(pwd):/backup \
busybox tar czf /backup/backup.tar.gz /data

Restore:

docker run --rm \
-v my_data_volume:/data \
-v $(pwd):/backup \
busybox tar xzf /backup/backup.tar.gz -C /

This is crucial for disaster recovery in production systems.

Volume Drivers

Docker supports third-party volume plugins for:

  • NFS
  • CIFS
  • Cloud storage (e.g., EBS, GCP Persistent Disks)

Example:

docker volume create \
--driver rexray/ebs \
--opt size=10 \
ebs_volume

Use cases include container orchestration, cloud-native storage, and multi-host Docker environments.

Best Practices

  • Use named volumes for better traceability and reuse
  • Avoid storing application data in the container filesystem
  • Keep volumes under version control via Docker Compose or infrastructure as code
  • Clean up unused volumes with docker volume prune
  • Use volume plugins for advanced use cases (HA, backups, multi-host)

Conclusion

Docker volumes are essential for managing persistent, portable, and isolated data in containerized applications. Whether you’re running a single container database or orchestrating services across clusters, mastering volume usage ensures your application state is durable and production-ready.

By understanding how to create, manage, and back up volumes, you can ensure your containers handle data reliably — now and as they scale.