I compiled and ran my first big job on the computer, but after a few minutes it died with the message "Cpu limit exceeded". How do I run big jobs?

Interactive jobs are limited to 600 seconds.

  1. Information on how to run your job via the SLURM job queueing system is in the user manual.

  2. Contact the analyst for help at hpc@asc.edu.

How do I use X-window based software on the DMC and SGI Ultraviolet?

The following commands can be used to setup a X-window connection to the DMC from a machine running UNIX X-windows. The commands might be slightly different from a Macintosh or PC with an X-window emulator.

  1. ssh -Y user_id@dmc.asc.edu (where user_id is your login)

  2. Type the command

  3. See the HPC User Manual for additional information on how to install and use X-Windows

How do I find out how much memory and CPU time my job used?

After the job has completed, type the command “jobinfo -j JOBNUMBER”.

What do I do if my disk quota is exceeded?

All user accounts on the SGI Ultraviolet and DMC have disk quotas, which determine how much information can be stored in the home directory and it's subdirectories. By default, this quota is 20 GB. Users can see their disk quota by typing "quota" or "usage".

Please note that it has always been the policy that disk space on the supercomputers is for work in progress, not permanent backup or archival. Completed work should be transfered to a campus facility for permanent storage.

While a calculation is in progress, the /scratch file system provides a large amount of temporary disk space. The amount of space that can be used on /scratch is limited by the choice of job queue. To see the queue disk limits, type "qlimits". Any files created on /scratch must be removed within one week after the calculation completes. Files left on /scratch more than a week are automatically deleted.

If the nature of your work is such that you must have a larger home directory quota, you can request a larger quota. Users can request up to 1 TB quotas at no charge. Send an email with your request and a brief justification to David Young at dyoung@asc.edu

For quotas over 1 TB, please contact us to obtain a quote to purchase additional resources. To obtain a formal written quote for disk space, contact Mrs. Donna Daniel, Director of Client Services, at ddaniel@asc.edu or 334-242-0175.

What is the batch system and how is it used?

Unlike PC's, these platforms are not designed for interactive work. Therefore, jobs that need running are submitted to a batch system for processing. The system handles multiple requests and schedules each job based on which batch queue was requested. To see a list of available queues, type qlimits at the prompt.

  1. To utilize the batch system, contact the analyst for help at hpc@asc.edu.

  2. If you are using an application package, run scripts are available which automatically submit your job for you. These are usually located in /apps/scripts. All you do is run the script and answer the questions.

  3. If you are compiling your own code, the analyst has scripts designed to compile, execute and scp your code anywhere you desire.

  4. If you feel comfortable using Unix scripts, prepare a simple script that runs your executable and submit it to the appropriate queue with the run_script command as follows

    run_script <scriptname>

How can I get help with my code?

Contact the analyst at hpc@asc.edu

How do I find out what applications are available on the DMC or SGI Ultraviolet?

  1. Point your browser to ASA HPC Software Tools

  2. Contact the HPC technical support staff at hpc@asc.edu