How do I specify new dockerd graph setting when running cAdvisor with docker

[dls314]

I'm running dockerd with --graph/mnt/docker to move the root of the docker runtime from /var/lib/docker.

How do I convey this change to cAdvisor?

I've tried the following when running the cAdvisor container, but the filesystem UI block for each container in cAdvisor's display remains empty, so I suspect it hasn't worked.

docker run \
...
  --volume=/mnt/docker:/var/lib/docker:ro \
...
  google/cadvisor:lates