There are circumstances where you will need to tune certain parameters. A common need is the ability to create very large files. A user with appropriate privilege can change the ulimit for the shell process being run by using the ulimit shell command of sh(C), or by modifying the ULIMIT line in the /etc/default/login file. Alternately, you can modify the system SFSZLIM for all users. The SFNOLIM parameter and other commonly encountered limits are summarized in the following table.
| Desired Improvement | Parameters |
|---|---|
| Performance improvement. | Largely automated. Some improvement possible depending on which resources your workload uses. See ``Paging parameters'' and ``Managing system performance''. |
| Users need to create bigger files. | SFSZLIM, HFSZLIM |
| Each user needs to open more files. | SFNOLIM, HFNOLIM |
| Each user needs to run more processes. | MAXUP, NPROC |