Docker Remote Volumes Cheatsheet
Remote volumes allow containers to access persistent storage that is not on the local host. This is crucial for applications that run in multi-host environments, such as a cluster of servers.
How They Work
Unlike local volumes, which are simply directories on the host's filesystem, remote volumes are managed by a **third-party storage solution**. Docker communicates with this solution through a **volume plugin**.
The plugin acts as a bridge, translating Docker's volume commands into API calls for the remote storage system, such as **AWS EFS**, **Google Cloud Storage**, or **Azure Files**.
Local vs. Remote Volumes
| Feature | Local Volumes | Remote Volumes |
|---|---|---|
| **Data Location** | On the local host's filesystem. | On a remote storage system in the cloud or network. |
| **Management** | Managed directly by the Docker daemon. | Managed by a Docker Volume Plugin that interfaces with a third-party service. |
| **Use Case** | Single-host applications; data persistence on a single machine. | Multi-host applications; data sharing across a cluster. |
Example Use Case
A team is running a web application on a cluster of Docker hosts. They use a remote volume to store user uploads. This ensures that no matter which host a container is running on, it can access the same set of files.
The command to create and use a remote volume depends on the specific plugin, but it generally looks like this:
# Create a volume using a specific driver (plugin)
docker volume create --driver [PLUGIN_NAME] --name [VOLUME_NAME]
# Run a container and mount the remote volume
docker run -d -v [VOLUME_NAME]:/app/data my-image The -v flag still binds the volume to a path in the container, but the underlying data is stored remotely, managed by the plugin.