ARCHIVED: In Unix, how should I submit CPU-intensive jobs?

Several mechanisms are available for handling large jobs in Unix, including reducing the priority of a process, running a process in the background, and, on some systems, submitting batch jobs.

• Batch jobs
• Changing a job's priority and running a job in the background

Batch jobs

For information about the at and batch commands, see ARCHIVED: In Unix, what are the at and batch commands, and how do I use them to submit non-interactive job requests?

For information about using TORQUE (based on OpenPBS) on Karst, or Mason at IU, see ARCHIVED: Use TORQUE to submit and manage jobs on high performance computing systems

Although Big Red II uses TORQUE for resource management, Big Red II job scripts must contain commands and directives specific to Big Red II's programming environment and system architecture; see ARCHIVED: Run batch jobs on Big Red II

Changing a job's priority and running a job in the background

To immediately execute a process at a lower priority, use the nice command. For example, to run a program called a.out at lower priority, at the Unix shell prompt, enter:

 nice a.out

To let the job run in the background (so you can keep working interactively), add an ampersand (&) to the end of the command line:

 nice a.out &

When the job is complete, you will see something similar to this:

 [1] Done ls (csh/tcsh)

For more on the nice command, see the manual (man) page, which you can access by entering:

 man nice

For more information on how to work with background processes, see the man page for your shell (e.g., csh, tcsh, ksh, bash).