Docker Volumes and Bind Mounts
Docker Volumes and Bind Mounts provide different mechanisms for managing data in containers. Here’s an outline:
Docker Volumes
Definition:
Docker volumes are a mechanism for persisting data outside of the container’s filesystem. Volumes are managed by Docker and are independent of the container’s lifecycle. This means that even if a container is deleted, the volume’s data remains available.
Purpose:
- Data persistence: Data stored in volumes persists even if the container is removed or recreated.
- Data sharing: Volumes can be shared between multiple containers.
- Data backup and restore: Volumes can be easily backed up and restored.
Example:
docker run -v data:/var/lib/myapp myapp
In this example, a volume named data is created and mounted to the /var/lib/myapp directory inside the container.
Bind Mounts
Definition:
Bind mounts, also known as volume mounts, directly mount a host directory into a container. This allows the container to access files and directories on the host system.
Purpose:
- Development: Bind mounts are often used in development environments to allow access to code and other files from the host system.
- Data sharing: Bind mounts can be used to share data between the host system and container.
- Performance: For small files, bind mounts can provide better performance than volumes.
Example:
docker run -v /home/user/code:/app myapp
In this example, the /home/user/code directory on the host system is mounted to the /app directory inside the container.
Differences:
- Data Persistence: Volumes persist data, while bind mounts link the data to the host system.
- Location: Volumes are managed by Docker, while bind mounts link to the host system’s directory.
- Sharing: Volumes are easier to share between multiple containers than bind mounts.
Recommendations:
- Use volumes for data persistence and sharing across multiple containers.
- Use bind mounts for development purposes and sharing data between the host system and a container.
Additional Resources:
