Docker out of space but thinpool lvm direct used

General
1

hi
I’m using docker 17.09.1-ce and created a direct-lvm for docker to use.

Data Space Used: 14.49GB
Data Space Total: 51.02GB
Data Space Available: 36.53GB
Metadata Space Used: 6.377MB
Metadata Space Total: 536.9MB
Metadata Space Available: 530.5MB
Docker Root Dir: /var/lib/docker
thinpool docker twi-a-t— 47.51g 28.39 1.19

which is an additonal disk /dev/sda8 docker lvm2 a-- 50.02g but / is showing out of space -
100% full on its 15gb. I thought docker was using this other device, am i misconfigured or misunderstanding ?
DOCKER_OPTS=“–storage-driver=devicemapper --storage-opt=dm.thinpooldev=/dev/mapper/docker-thinpool”
SLES 12 SP3

docker prune cleared 4gb from docker info results and a teeny bit from / but still / showing full and the only place that has lots of size about it is /var/lib/docker.

Thanks