Frequently Asked Questions: Difference between revisions

The <tt>LevelFS</tt> column gives you information about your over- or under-consumption of cluster resources: when <tt>LevelFS</tt> is greater than one, you are consuming fewer resources than your fair share, while if it is less than one you are consuming more. The more you overconsume resources, the closer the value gets to zero and the more your pending jobs decrease in priority. There is a memory effect to this calculation so the scheduler gradually "forgets" about any potential over- or under-consumption of resources from months past. Finally, note that the value of <tt>LevelFS</tt> is unique to the specific cluster.   

Start times shown by <tt>squeue</tt> are accurate but conditional.  

[[Running jobs|Slurm]] schedules future START_TIME for high-priority pending jobs.  These expected start times are computed from current information:  

* what resources will be made available by running jobs that complete; and

* resources needed by other, higher-priority jobs waiting to run

The start times are conditional - <tt>Slurm</tt> invalidates these future plans if:  

* jobs end early, changing which resources become available;

* prioritization is perturbed: submission of higher-priority jobs or cancellation of queued jobs

On Compute Canada general purpose clusters, new jobs are submitted about every five seconds, and 30-50% of jobs end early,

so <tt>Slurm</tt> often discards and recomputes its future plans.

Most waiting jobs have a START_TIME of "N/A", which stands for "not available", meaning <tt>Slurm</tt> is not attempting to project a start time for that job.

For jobs which are already running, the start time reported by <tt>squeue</tt> is perfectly accurate.

</translate>