Data Persistence with Volumes
Implement Docker volumes to ensure your application data persists beyond the lifecycle of individual containers.
Ephemeral Containers
When you run an application inside a Docker container, any data it creates or modifies is, by default, stored within the container's writable layer. This data is called ephemeral.
This means that if the container is stopped, removed, or crashes, all that valuable data is lost! This is a big problem for databases, user uploads, or configuration files that need to stick around.
We need a robust way to store data outside the container's lifecycle.
What are Docker Volumes?
Docker volumes are the preferred and most efficient way to persist data generated by and used by Docker containers. They are designed to solve the problem of ephemeral data.
- Volumes are managed by Docker itself, making them more robust and portable.
- They live on the host filesystem, but Docker handles their creation, management, and mounting to containers.
- Crucially, volumes are designed to outlive the container that created them, ensuring your data is safe and persistent.
All lessons in this course
- Understanding Docker Network Types
- Configuring Container Networks
- Data Persistence with Volumes
- Connecting Containers with Docker Compose Networks