Stop all containers

 docker stop $(docker ps -a -q)

Delete images

• By image name

docker rmi $(docker images  'imagename' -a -q) 

• Untagged images

docker rmi $(docker images -f "dangling=true" -q) 

Export/import image as .tar file

• Save image to .tar file

 docker save -o <filename>.tar <image-name>:<image-tag>

• Load/import image

docker load -i <filename>.tar

Move the Docker directory

We gonna move the default docker directory "/var/lib/docker" to another.
Usually doing it when the docker host disk was not propertly dimensioned and we cannot increase de size.

Stop the docker service

service docker stop

Verify if docker process is running yet

ps faux | grep docker --color

Verify there is some files in the default docker directory

ls -la /var/lib/docker/

Make a backup from docker directory

tar -zcC /var/lib docker > /dados/docker/bkp/var_lib_docker-backup-$(date +%s).tar.gz

Move the directory /var/lib/docker to new home

mv /var/lib/docker /dados/docker

Create a symlink

ln -s /dados/docker /var/lib/docker

Verify symlink working well

ls -la /var/lib/docker

Start the docker service

service docker start