+If your worker hostnames are already assigned by other means, but the full set of names is _not_ known in advance, you can use the @slurm.conf@ and @application.yml@ settings in the previous example, but you must also update @slurm.conf@ (both on the controller and on all worker nodes) and run @sudo scontrol reconfigure@ whenever a new node comes online.
+
+h2. Enable SLURM job dispatch
+
+In your API server's @application.yml@ configuration file, add the line @crunch_job_wrapper: :slurm_immediate@ under the appropriate section. (The second colon is not a typo. It denotes a Ruby symbol.)
+
+h2. Crunch user account
+
+Run @sudo adduser crunch@. The crunch user should have the same UID, GID, and home directory on all compute nodes and on the dispatcher (API server).
+
+h2. Run the Crunch dispatcher service
+
+To dispatch Arvados jobs:
+
+* The API server script @crunch-dispatch.rb@ must be running.
+* @crunch-job@ needs the installation path of the Perl SDK in its @PERLLIB@.
+* @crunch-job@ needs the @ARVADOS_API_HOST@ (and, if necessary, @ARVADOS_API_HOST_INSECURE@) environment variable set.
+
+We recommend you run @crunch-dispatch.rb@ under "runit":http://smarden.org/runit/ or a similar supervisor. Here's an example runit service script:
+
+<notextile>
+<pre><code>#!/bin/sh