Everything your system does (running processes, reading files, or saving data) uses part of your system's limited resources of CPU, RAM, and disk space. To prevent users or processes from consuming more than their fair share of these resources, and to optimize their use, your SCO provides tunable parameters.
Each tunable parameter is represented by a name and is set to a specific value on your system. This value defines a limit on a particular system resource that users or processes (programs that are running) can consume. The system also stores the minimum and maximum values allowed for the parameter.
For example, the MAXUP parameter defines the maximum number of processes any system user (besides root) can have running at the same time. By default, the MAXUP parameter is set to ``60'', with the system limiting the value to between ``15'' and ``60''. Within these constraints, no user can have more than 60 processes running at a time.
Your SCO system includes a graphical interface for changing your tunable parameters called the System Tuner. This allows you to display and change your system's tunable parameters, or reset them to their original values. It also prevents you from changing parameters to values that are outside the acceptable limits.
Though the System Tuner is recommended for changing your tunables, you can also change parameters using the idtune(1M) utility.