Orphaned Docker mounted host volumes

Question

I just inspected my /var/lib/docker/volumes folder and discovered that is bursting with folders named as Docker UUIDs each of which contain a config.json file with contents along the lines of

{"ID":"UUID","Path":"/path/to/mounted/volume","IsBindMount":true,"Writable":true}

where

/path/to/mounted/volume

is the path to the folder on the host that was mounted on to a docker container

A few containers were stopped. So these files I’m seeing in my folder are they the stopped containers or something else?

Answer 1

For Docker 1.9 and up there's a native way:

List all orphaned volumes with

$ docker volume ls -qf dangling=true

Eliminate all of them with

$ docker volume rm $(docker volume ls -qf dangling=true)