+h2. Configure the Docker cleaner
+
+The arvados-docker-cleaner program removes least recently used docker images as needed to keep disk usage below a configured limit.
+
+{% include 'notebox_begin' %}
+This also removes all containers as soon as they exit, as if they were run with @docker run --rm@. If you need to debug or inspect containers after they stop, temporarily stop arvados-docker-cleaner or run it with @--remove-stopped-containers never@.
+{% include 'notebox_end' %}
+
+Install runit to supervise the Docker cleaner daemon. {% include 'install_runit' %}
+
+Configure runit to run the image cleaner using a suitable quota for your compute nodes and workload:
+
+<notextile>
+<pre><code>~$ <span class="userinput">sudo mkdir -p /etc/sv</span>
+~$ <span class="userinput">cd /etc/sv</span>
+/etc/sv$ <span class="userinput">sudo mkdir arvados-docker-cleaner; cd arvados-docker-cleaner</span>
+/etc/sv/arvados-docker-cleaner$ <span class="userinput">sudo mkdir log log/main</span>
+/etc/sv/arvados-docker-cleaner$ <span class="userinput">sudo sh -c 'cat >log/run' <<'EOF'
+#!/bin/sh
+exec svlogd -tt main
+EOF</span>
+/etc/sv/arvados-docker-cleaner$ <span class="userinput">sudo sh -c 'cat >run' <<'EOF'
+#!/bin/sh
+exec python3 -m arvados_docker.cleaner --quota <b>50G</b>
+EOF</span>
+/etc/sv/arvados-docker-cleaner$ <span class="userinput">sudo chmod +x run log/run</span>
+/etc/sv/arvados-docker-cleaner$ <span class="userinput">sudo ln -s "$(pwd)" /etc/service/</span>
+</code></pre>
+</notextile>
+
+If you are using a different daemon supervisor, or if you want to test the daemon in a terminal window, an equivalent shell command to run arvados-docker-cleaner is:
+
+<notextile>
+<pre><code><span class="userinput">python3 -m arvados_docker.cleaner --quota <b>50G</b></span>
+</code></pre>
+</notextile>
+
+h2. Add a Crunch user account