Some way to clean up / identify contents of /var/lib/docker/overlay

General
4

So ```docker system prune -a -f` doesn’t help.

I’ve upgraded docker (and rm -rf /var/lib/docker/* during the upgrade, so this isn’t from before the upgrade):

# docker info | egrep '^(Server Version|Storage)'
Server Version: 17.03.1-ce
Storage Driver: overlay2

Docker isn’t aware of any containers or images:

[root@*** ~]# docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
[root@*** ~]# docker images -a
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE

Neither prune command helps:

[root@*** ~]# docker volume prune -f
Total reclaimed space: 0 B
[root@*** ~]# docker system prune -a -f
Total reclaimed space: 0 B

There’s a lot of dirs left behind in /var/lib/docker/overlay2:

[root@*** ~]# ls -la /var/lib/docker/overlay2/ | wc -l
113

Taking up a fair bit of space (given they don’t seem to “belong to anything”):

[root@*** ~]# du -sch /var/lib/docker/overlay2/*
40K	/var/lib/docker/overlay2/0507f5e8d32952a9ccf45bad488c084f017d9db3e153d6f22e46532edadef58e
80K	/var/lib/docker/overlay2/0cc693976ed3d560f0a13c03ce5ab60645e332da1d97b9c775ebc9d7dde233ae
36K	/var/lib/docker/overlay2/0db10721d06e14dc934f9a54313885e3a5a7e53cc0473897e53a0f9ec68d0ee6
169M	/var/lib/docker/overlay2/0ff14195d187ce0effa72423b380fff6c4b5a1efbcdca9e8ba5eff8e99147fd8
[...]
321M	/var/lib/docker/overlay2/cb45cb0ac04e59f328f05379aa76126eaa6d9bbd10e0956861f0b8a2ca9f505b
119M	/var/lib/docker/overlay2/cf0228e906c84f5ba1ec918a5a5872f077fbf572870cdb414899188d29ea807a
586M	/var/lib/docker/overlay2/d4490f059916dcf64e3cd95a0af310865b293bcc1e89d4ab68051744e383b5aa
[...]
5.7G	total

There’s gotta be some way I can map from the contents of that directory back to what owns it?