[slurm-users] OpenMPI interactive change in behavior?

[Chris Samuel]

On Monday, 26 April 2021 2:12:41 PM PDT John DeSantis wrote:

> Furthermore,
> searching the mailing list suggests that the appropriate method is to use
> `salloc` first, despite version 17.11.9 not needing `salloc` for an
> "interactive" sessions.

Before 20.11 with salloc you needed to set a SallocDefaultCommand to use srun 
to push the session over on to a compute node, and then you needed to set a 
bunch of things to prevent that srun from consuming resources that the 
subsequent srun's would need.  That was especially annoying when you were 
dealing with GPUs as you would need to "srun" anything that needed to access 
them (when you used cgroups to control access).

With 20.11 there's a new "use_interactive_step" option that uses similar 
trickery, except Slurm handles not consuming those resources for you and 
handles GPUs correctly.

So for your 20.11 system I would recommend giving salloc and the 
"use_interactive_step" option a go and see if it helps.

All the best,
Chris
-- 
  Chris Samuel  :  http://www.csamuel.org/  :  Berkeley, CA, USA