Removing unused containers, networks and images
To remove all unused containers, networks and images you can use docker system prune. I recently ran this on a server that had no disk space left and managed to recover over 30GB.
Example usage and output:
docker system prune
WARNING! This will remove:
- all stopped containers
- all networks not used by at least one container
- all dangling images
- all build cache
Are you sure you want to continue? [y/N] y
Deleted Containers:
...
Deleted Networks:
...
Deleted Images:
...
Total reclaimed space: 30.57 GB
Removing unused volumes
Optionally you can also remove unused volumes, however this must be considered carefully due to the possibility of data loss. Any volume that is not currently being used by a container will be removed!
docker system prune --volumes
WARNING! This will remove:
- all stopped containers
- all networks not used by at least one container
- all volumes not used by at least one container
- all dangling images
- all dangling build cache
Are you sure you want to continue? [y/N] y
...
Total reclaimed space: 13.5 MB
Other options
To see all the available options you can run docker system prune --help which will print out the following:
Usage: docker system prune [OPTIONS]
Remove unused data
Options:
-a, --all Remove all unused images not just dangling ones
--filter filter Provide filter values (e.g. "label=<key>=<value>")
-f, --force Do not prompt for confirmation
--volumes Prune volumes
For further information and examples refer to the Docker docs: https://docs.docker.com/engine/reference/commandline/system_prune/