[slurm-users] Avoiding fragmentation

Hi,

I'm trying to figure out how to deal with a mix of few- and many-cpu jobs. By that I mean most jobs use 128 cpus, but sometimes there are jobs with only 16. As soon as that job with only 16 is running, the scheduler splits the next 128 cpu jobs into 96+16 each, instead of assigning a full 128 cpu node to them. Is there a way for the administrator to achieve preferring full nodes? The existence of pack_serial_at_end makes me believe there is not, because that basically is what I needed, apart from my serial jobs using 16 cpus instead of 1.

Gerhard