Pitzer
HOWTO: Debugging Tips
This article focuses on debugging strategies for C/C++ codes, but many are applicable to other languages as well.
Rubber Duck Debugging
This approach is a great starting point. Say you have written some code, and it does not do what you expect it to do. You have stared at it for a few minutes, but you cannot seem to spot the problem.
OSC internal network problems 25 Sept. 2020
OSC is currently experiencing problems with its internal network. Interactive sessions may be slow or unresponsive, but running jobs should not be affected.
Guidance on Requesting Resources on Pitzer
In late 2018, OSC installed 260 Intel® Xeon® 'Skylake' processor-based nodes as the original Pitzer cluster. In September 2020, OSC installed additional 398 Intel® Xeon® 'Cascade Lake' processor-based nodes as part of a Pitzer Expansion cluster.
Pitzer expansion and slurm migration
OSC has expanded Pitzer Cluster approximately tripling the peak capacity.
Pitzer Downtime September 22, 2020
An approximately 3-hour downtime for the Pitzer system is scheduled starting from 9 a.m. Tuesday, September 22, 2020, to finalize the Slurm transition on the Pitzer system. This will affect both the Pitzer legacy compute and login nodes, as well as the new Pitzer hardware. During this downtime time, users will not be able to access Pitzer and submit jobs. Other OSC services, including Owens and Ruby Clusters, web portals, and HPC file servers will be available.
ssh connection timeouts and slowness
OSC users may experience slow connections or connection timeouts. The cause appears to be a pattern of coordinated, distributed ssh scans of OSC systems. OSC staff is currently investigating ways to mitigate this.
Please contact oschelp@osc.edu if there are any questions/concerns.
Pitzer Expansion Early User Program
In preparation for the deployment of the new hardware as well as the Slurm migration on Pitzer in fall 2020, OSC would like to invite all members of the client community to participate in the Pitzer Expansion Early User Program in order to test the functionality of new hardware, including Dual GPU and Quad GPU features, and test the new Slurm scheduler and its TORQUE/Moab compatibility. Jobs that are eligible for the early user program will not be charged and there is no registration required, all OSC users are eligible.
Slurm Migration Issues
This page documents the known issues for migrating jobs from Torque to Slurm.
$PBS_NODEFILE and $SLURM_JOB_NODELIST
Please be aware that $PBS_NODEFILE is a file while $SLURM_JOB_NODELIST is a string variable.
The analog on Slurm to cat $PBS_NODEFILE is srun hostname | sort -n
Environment variables are not evaluated in job script directives
Environment variables do not work in a slurm directive inside a job script.
Steps on How to Submit Jobs
How to Submit Interactive jobs
There are different ways to submit interactive jobs.
Using sinteractive
You can use the custom tool sinteractive as:
