Overview and Basic Description
Euclid is a single node system with 48 processors. It supports both multiprocessing (MPI) and multithreading programming models.
All Euclid jobs are interactive.
To launch an MPI job, type in this at the shell prompt:
% mpirun -np numprocs executable_name
where numprocs is the total number of MPI processes that will be executed.
Interactive Usage Policy
Due to the dynamic and unpredictable nature of visualization and data analysis, NERSC will attempt to provide equitable access to Euclid's resources through the enforcement of certain usage guidelines. The most crucial resources are the processor cores (48) and memory (512 GB).
Processor Core Usage Policy
No single interactive job should use more than 12 processor cores. A single interactive job should use no more than 12 processor-hours. This might be spread over multiple processor cores, e.g. a single job using 1 processor core for 12 hours or a single job using 12 processor for 1 hour, etc.
Memory Usage Policy
No single interactive job should use more than 200 GB of physical memory.
Note: as of September, 2011, Euclid is enforcing a per-process memory limit (VMEM, 16-GB soft/ 32-GB hard). If you need to run a job with a lot of memory a better choice is the 1 Terabyte Node on the Carver system. See the "Extra-Large-Memory Node" portion of the Memory Considerations web page for more details.
Exception to the Interactive Policy
It is not the purpose of these policies to prohibit interactive jobs that fall outside of the above guidelines. NERSC will attempt to accomodate requests for interactive resources greater than those described above. Users who think that they have a legitimate need for larger interactive resources should contact HPC Consulting before attempting to run such interactive jobs.
There is no batch system on Euclid so all jobs are interactive and launched directly from the command line.