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ULHPC Slurm Partitions 2.0

In Slurm multiple nodes can be grouped into partitions which are sets of nodes aggregated by shared characteristics or objectives, with associated limits for wall-clock time, job size, etc. These limits are hard limits for the jobs and can not be overruled.

To select a given partition with a Slurm command, use the -p <partition> option:

srun|sbatch|salloc|sinfo|squeue... -p <partition> [...]

You will find on ULHPC resources the following partitions (mostly matching the 3 types of computing resources)

  • batch is intended for running parallel scientific applications as passive jobs on "regular" nodes (Dual CPU, no accelerators, 128 to 256 GB of RAM)
  • gpu is intended for running GPU-accelerated scientific applications as passive jobs on "gpu" nodes (Dual CPU, 4 Nvidia accelerators, 768 GB RAM)
  • bigmem is dedicated for memory intensive data processing jobs on "bigmem" nodes (Quad-CPU, no accelerators, 3072 GB RAM)
  • interactive: a floating partition intended for quick interactive jobs, allowing for quick tests and compilation/preparation work.
    • this is the only partition crossing all type of nodes (thus floating).
    • use si, si-gpu or si-bigmem to submit an interactive job on either a regular, gpu or bigmem node


AION (type) #Nodes (cores/node) Default/MaxTime MaxNodes PriorityTier
interactive (floating) 318 30min - 2h 2 100
batch (default) 318 (128c) 2h - 48h 64 1


IRIS (type) #Nodes (cores/n) Default/MaxTime MaxNodes PriorityTier
interactive (floating) 196 30min - 2h 2 100
batch (default) 168 (28c) 2h - 48h 64 1
gpu 24 (28c) 2h - 48h 4 1
bigmem 4 (112c) 2h - 48h 1 1

Queues/Partitions State Information

For detailed information about all available partitions and their definition/limits:

scontrol show partitions [name]

Partition load status

You can of course use squeue -p <partition> to list the jobs currently scheduled on a given, partition <partition>.

As part of the custom ULHPC Slurm helpers defined in /etc/profile.d/, the following commands have been made to facilitate the review of the current load usage of the partitions.

Command Description
irisstat, aionstat report cluster status (utilization, partition and QOS live stats)
pload [-a] i/b/g/m Overview of the Slurm partition load
listpartitionjobs <part> List jobs (and current load) of the slurm partition <part>

Partition load with pload

$ pload -h
Usage: pload [-a] [--no-header] <partition>
 => Show current load of the slurm partition <partition>, eventually without header
    <partition> shortcuts: i=interactive b=batch g=gpu m=bigmem
   -a: show all partition
$ pload -a
  Partition  CPU Max  CPU Used  CPU Free     Usage[%]
      batch     4704      4223       481       89.8%
        gpu      672       412       260       61.3% GPU: 61/96 (63.5%)
     bigmem      448       431        17       96.2%

Partition Limits

At partition level, only the following limits can be enforced:

  • DefaultTime: Default time limit
  • MaxNodes: Maximum number of nodes per job
  • MinNodes: Minimum number of nodes per job
  • MaxCPUsPerNode: Maximum number of CPUs job can be allocated on any node
  • MaxMemPerCPU/Node: Maximum memory job can be allocated on any CPU or node
  • MaxTime: Maximum length of time user's job can run

Last update: February 9, 2021