changelog Updates

SLURM's Default Memory Per CPU Increased (1GB --> 2GB)

2020-05-07T18:12:00.001Z

Hi All,

Based on previous usage, the default allocation of 1GB of memory per cpu is too low. I have now increased this default to 2GB of memory per cpu.

If you are not setting memory requirements in your job(s), this will change will affect them.

If you are already setting memory requirements in your job(s), this change will not affect you.

Best practice is to specify memory in all jobs. If you haven’t been doing so and are now running into issues (waiting in partitions for longer than usual), you’ll now need to specify memory per cpu in jobs.

--mem-per-cpu=1G # when passed via command line,
or
#SBATCH --mem-per-cpu=1G # when added to a submission script.

Adding either option should set your memory per cpu back to 1GB.

** Again, if you are already using the --mem= or --mem-per-*= options, no changes are required for your job(s).

Thank You

SLURM Priority Adjustment

2020-05-07T15:15:00.001Z

Since priorities were not working for those users who use Memex less frequently and in smaller batches of submitted jobs, these parameters were adjusted:

PriorityWeightFairShare=20000
PriorityWeightTRES=CPU=1000,Mem=2000,GRES/gpu=3000

As a result gres/gpu was added to:

AccountingStorageTRES=cpu,mem,energy,node,billing,fs/disk,vmem,pages,gres/gpu

This functionality changes in SLURM 19+, but our current version is 18.08 which is the latest version packaged with OpenHPC 1.3.

Update: AcctGatherFilesystemType was also enabled for lustre.

New Nodes Added - memex-c[117-124]

2019-02-20T21:40:00.001Z

Nodes, memex-c[117-124], were added to Memex on 2/13/19. These nodes are identical to memex-c[109-116], which all have 256GB of raw memory and up to 250GB of free/unused memory per node.

Users can request any of these nodes by adding the SLURM option "-C 250G" to sbatch scripts, srun, or salloc. For instance, adding:

#SBATCH -C 250G

to any sbatch script will only try to run on these servers, memex-c[109-124]. They are available in SHARED and DTM partitions on Memex.