No centos localize docker service

# find / -iname docker.service

edite

# vim /usr/lib/systemd/system/docker.service

Localize a seguinte linha

ExecStart=/usr/bin/dockerd

configure como, acionando -g e o novo diretório

ExecStart=/usr/bin/dockerd -g /storage/var/lib/docker

Reconfigure o systemctl

# systemctl daemon-reload

Voilá

# service docker start

docker Storage