What are the differences between host, anonymous, and named Docker volumes? In this blog post, we will explore their differences as well as their advantages and disadvantages.
Host volumes
A host volume can be accessed from within a Docker container and is stored on the host. To create a host volume, run:
docker run -v /path/on/host:/path/in/containerAdvantages:
- Offers direct access to the file system of the host machine.
- Can be used to share data between the host and the container.
- Allows for easy debugging of container applications.
Disadvantages:
- The volume’s data can be modified or deleted accidentally by the host or another container.
- Can have compatibility issues with different host systems.
Anonymous volumes
The location of anonymous volumes is managed by Docker. It can be difficult to refer to the same volume when it is anonymous. To create an anonymous volume, run:
docker run -v /path/in/containerAlthough anonymous volumes provide flexibility, they are not used as often now that named volumes have been introduced.
Advantages:
- Easier to use since Docker handles their creation.
- Automatically deleted when the container is removed.
- Provides a level of isolation between the container and the host machine.
Disadvantages:
- Cannot be shared between containers.
- Cannot be backed up or restored.
- Difficult to manage and track.
Named volumes
Named volumes and anonymous volumes are similar because Docker manages where they are located. However, named volumes can be referred to by name. To create a named volume, run:
docker volume create somevolumename
docker run -v somevolumefileName:/path/in/containerLike anonymous volumes, named volumes provide flexibility, but they are also explicit, which makes them easier to manage.
You can also specify Docker volumes in your docker-compose.yaml file using the same syntax as the examples above.
Advantages:
- Easier to manage and share between containers.
- Provides a clear separation of concerns between the container and the storage.
- Can be backed up, restored, and migrated.
Disadvantages:
- Requires creating the volume ahead of time.