dockerdevice-mapper

How to clean docker devicemapper folder properly ?


I have some problem about the storage. The folder /var/lib/docker/devicemapper/ is taking 50% of my storage.

In the folder /var/lib/docker/devicemapper/mnt, I have many empty folders.

How can I properly clean docker devicemapper and remove all unused mapping ?


Solution

  • With recent versions of Docker you can see the space used with:

    docker system df

    and prune it with:

    docker system prune

    The above command combines the prune command that exists for volumes, containers, images and networks:

    docker volume prune

    docker container prune

    docker image prune

    docker network prune

    Each command has a --help option documenting a -f (--force) option to avoid asking you questions. It must be used with care.

    -o-

    On older versions of Docker I ran the script:

    #!/bin/bash
    
    # Remove dead containers (and their volumes)
    docker ps -f status=dead --format '{{ .ID }}' | xargs -r docker rm -v
    # Remove dangling volumes
    docker volume ls -qf dangling=true | xargs -r docker volume rm
    # Remove untagged ("<none>") images
    docker images --digests --format '{{.Repository}}:{{.Tag}}@{{.Digest}}' | sed -rne 's/([^>]):<none>@/\1@/p' | xargs -r docker rmi
    # Remove dangling images
    docker images -qf dangling=true | xargs -r docker rmi
    # Remove temporary files
    rm -f /var/lib/docker/tmp/*