Rancher master containers

Rancher master seems to download all the containers
The containers directory is 10G. Why does the master node download any containers other than rancher/master ?

What do you mean by “Rancher Master”?

Sorry I meant my node which runs rancher/server. It also appears that the 10G all came from various versions of rancher/server.

Rancher server does not download any containers itself. The Rancher/agents will launch containers on your nodes when you request it. You can remove older versions of rancher server image. If you are using the Database inside the container then by default it will live in /var/lib/docker/volumes someplace. It can take up a bit of space.

When cleaning out old images/containers make sure you do not delete the original container that has the MySQL db. If you have been upgrading with --volumes-from then that original container owns the volume and deleting it will remove the DB.