MeSU supercomputer resources are managed by PBS job scheduler.
Users must submit their jobs on one of the computing system (beta or gamma) according to their needs.
This page describes the jobs categories and the limits enforced on each system in order maximize resource occupation and minimize wait times. These limits can change dynamically according to MeSU load and the number of users or jobs waiting for computing resources. When a user has jobs pending with “QOSJobLimit” reason, that means it has reached the limit of the corresponding job category.
Users do not have to declare their jobs category explicitly, it is derived from their resources needs (ncpus, walltime, etc.).
Overall, remember that resources are managed in a fair-share fashion, meaning that users that compute the most have a lower priority as long as other users with lower historic usage of the machine have jobs pending.
In order to specify the walltime limit of a job, use the ‘-l walltime’ parameter. For example :
#PBS -l walltime=03:20:10
Sets a maximal execution time of 3 hours 20 minutes 10 seconds.
Beta jobs categories and limits
When submitting a job on the Beta system, use preferably a number of CPUs that is a multiple of 24 which corresponds to the number of CPUs available on each node.
| Category | NCPUs range | Walltime limit | Running limit | Notes |
|---|---|---|---|---|
| Thin | [1..23] | 48 hours | - | shared node placement |
| Normal | [24..192] | 24 hours | - | |
| Large | [193..864] | 12 hours | - | |
| Giant | [865..1728] | 8 hours | 1728 CPUs per user | available by request only |
| Thin Long | [1..23] | 336 hours | 192 CPUs per user | shared node placement |
| Normal Long | [24..192] | 336 hours | 1152 CPUs per user | |
| Large Long | [193..864] | 96 hours | 1152 CPUs per user |
Gamma jobs categories and limits
When submitting a job in the Gamma system, users should specify the number of GPUs they whish to use.
Jobs in the Gamma system all fall in the same category and have the following limits :
– between 1 and 12 CPUs,
– between 1 and 2 GPUs,
– wall time limit of 48 hours.