Running Jobs on Nautilus
When you log into Nautilus at login.nautilus.nics.tennessee.edu or login.nautilus.nics.xsede.org, you are placed on one of two login nodes. Login nodes should be used for basic tasks such as file editing, file transfers, code compilation, data backup, and job submission.
The login nodes should not be used to run production jobs. Production work should be performed on the systems compute resources.
To submit a job to PBS, use the
qsub command. The most common way to use
qsub is to simply pass it the name of a 'batch script' that contains all of the information about running your job:
> qsub myscript.pbs
For information on how to write a batch script and the various PBS options available, see the Batch Scripts page.
You can also use
qsub to start an interactive session on Nautilus by including the
> qsub -I -A XXXYYY -l ncpus=16,walltime=1:00:00,mem=64GB
As you can see in this case, you must specify the PBS options along with the
qsub command (again, see the Batch Scripts page for an explanation of PBS options.)
Upon submission, your job will be placed in a particular queue. The job scheduler, Moab, uses queues to aid in the organization and scheduling of jobs. See the Queues page for the available queues on Nautilus and their benefits.
Nautilus supports MPI and OpenMP for running parallel jobs. See the Parallel Execution page for details on their use along with various examples.
If you need to run many concurrent instances of serial code, we provide the Eden tool for managing such jobs. Please see the Eden documentation page for instructions on use.
For information on how projects are charged for time on Nautilus, see the Job Accounting page.
Scheduling Policy - Nautilus
Moab on Nautilus is configured to do “first fit” backfill. Backfilling allows smaller, shorter jobs to use otherwise idle resources.
Computation Queue Policies
- The scheduler places a limit of one running computation job per user.
- Computation jobs can be preempted by analysis jobs at any time. Preempted jobs will be re-queued.
- The maximum wall time for computation jobs is 24 hours.
Analysis Queue Policies
- There is no limit on the number of running analysis jobs per user.
- The maximum wall time for analysis jobs is 24 hours.
VNC Session on Nautilus
For instructions on how to start a VNC session on Nautilus, see the VNC Session page.
NX Session on Nautilus
For instructions on how to start a NX session on Nautilus, see the NX Session page.