install docs for slurm don't allow multiple jobs per node
The install docs for setting up SLURM (http://doc.arvados.org/install/crunch2-slurm/install-slurm.html) include a configuration which disables SLURM's consumable resources support and forces assigning jobs to whole nodes:
There should at least be a mention in the docs that if you want multiple jobs per node (i.e. what I'd assume is the default desire for Crunch v2), you need something more like:
Issue 6520 (https://dev.arvados.org/issues/6520) has that configuration along with guidance on how to configure SLURM for node management, but this also appears to not be mentioned in the documentation:
SelectType=select/cons_res SelectTypeParameters=CR_CPU_Memory SuspendTime=600 ResumeProgram=/usr/bin/create-node SuspendProgram=/usr/bin/destroy-node
I suggest either changing the default configuration to use consumable resources or else adding it as an option in the install docs.