Why is docker image eating up my disk space that is not used by docker

Question

I have setup docker and I have used completely different block device to store docker\'s system data:

[root@blink1 /]# cat /etc/sysconfig/docker
# /etc/sysc         


        

Answer 1

Had the same problem. In my scenario my vbox was running out of storage space. After an investigation found out that my docker local volumes were eating up 30gb. Ubuntu 16.04 host.

To find out yours.

docker system df

TYPE                TOTAL               ACTIVE              SIZE                RECLAIMABLE
Images              3                   0                   1.361GB             1.361GB (100%)
Containers          0                   0                   0B                  0B
Local Volumes       7                   0                   9.413GB             9.413GB (100%)
Build Cache                                                 0B                  0B



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 build cache
Are you sure you want to continue? [y/N]

This frees up disk space of not used local volumes. At my scenario freed 20 GB of storage space. Make sure that containers which you want to keep are running before doing this if you want to keep them since this removes all stopped containers.