I have deleted all the images/containers
ubuntu@ubuntu:/var/lib/docker$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
ubuntu@ubuntu:/var/lib/docker$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
but I notice that there are still about 15GB inside /var/lib/docker
ubuntu@ubuntu:/var/lib/docker$ sudo du --max-depth=1 -h .
12G ./volumes
104K ./aufs
4,0K ./containers
1,3M ./image
4,0K ./trust
4,0K ./swarm
2,6G ./tmp
108K ./network
15G .
Questions:
How can I free up this space?
Is it safe to remove things inside
/var/lib/docker
?