Docker complains about "no space left on device", how to clean up?

I installed docker on a Debian 7 machine in the following way $ echo deb http://get.docker.io/ubuntu docker main > /etc/apt/sources.list.d/docker.list $ sudo apt-get update $ curl -sSL https://get.docker.com/ubuntu/ | sudo sh After that when I first tried creating an Image it failed with the following error time="2015-06-02T14:26:37-04:00" level=info msg="[8] System error: write /sys/fs/cgroup/docker/01f5670fbee1f6687f58f3a943b1e1bdaec2630197fa4da1b19cc3db7e3d3883/cgroup.procs: no space left on device" Here is the docker info Containers: 2 Images: 21 Storage Driver: aufs Root Dir: /var/lib/docker/aufs Backing Filesystem: extfs Dirs: 25 Dirperm1 Supported: true Execution Driver: native-0.2 Kernel Version: 3.16.0-0.bpo.4-amd64 Operating System: Debian GNU/Linux 7 (wheezy) CPUs: 2 Total Memory: 15.7 GiB WARNING: No memory limit support WARNING: No swap limit support How can I increase the memory? Where are the system configurations stored? From Kal's suggestions: When I got rid of all the images and containers it did free some space and the image build ran longer before failing with the same error. So the question is, which space is this referring to and how do I configure it?