[slurm-users] resource selection algorithm cons_tres ?

[Patrick Goetz]

I'm working on an inherited Slurm cluster, and was reading through the 
Slurm documentation when I found this in the Easy Configurator section 
(https://slurm.schedmd.com/configurator.easy.html)

  - cons_tres: Allocate individual processors, memory, GPUs, and other 
trackable resources
  - Cons_res: Allocate individual processors and memory
  - Cray XC: Cray XC systems running native Slurm without ALPS
  - Linear: Node-base resource allocation, does not manage individual 
processor allocation

I don't recall cons_tres being an option in Slurm 17.x, but also don't 
know how to find the old documentation to confirm.

Also, confused by this, as this appears to track GPUs, too, which 
previously were configured using Gres, as in:

GresTypes=gpu
NodeName=titan-3 Gres=gpu:titanv:8 RealMemory=250000 CPUs=40
NodeName=titan-4 Gres=gpu:titanv:7 RealMemory=250000 CPUs=40


Can anyone shed some light on this?  What's the functional difference 
between cons_res and cons_tres?

Thanks.