Unused Docker image and container can quickly take up your disk spaces.
Let’s check disk usage
Summary of data used. You can add
-v flag for detailed info.
$ docker system df TYPE TOTAL ACTIVE SIZE RECLAIMABLE Images 87 1 63.39GB 63.17GB (99%) Containers 1 0 0B 0B Local Volumes 69 1 2.732GB 2.683GB (98%) Build Cache 0 0 0B 0B
Remove unused data
The following command will remove:
- all stopped containers
- all networks not used by at least one container
- all dangling images (see below fo dangling images)
- all build cache By default, volumes are not removed to prevent important data from being deleted.
$ docker system prune WARNING! This will remove: - all stopped containers - all networks not used by at least one container - all dangling images - all dangling build cache Are you sure you want to continue? [y/N] y Deleted Containers: ... Total reclaimed space: 13.91GB
-a: Remove all unsued images not just dnaling ones.
--volumes: prune volumes.
What’s dangling images?
Docker images consist of multiple layers. Dangling images, are layers that have no relationship to any tagged images. They no longer serve a purpose and consume disk space.
You can list dangling iamges:
$ docker images -f dangling=true