Controls are used to limit or redirect resources.
A limit prevents a resource from exceeding a preset value. Some limits are system wide (such as the total number of processes allowed on a system) and some operate on a per-user basis (such as a file system quota). Since many limits are implemented by the Solaris software, the action, when a limit is reached, is to return an error code inside the application and possibly send a signal to the process. Well-written applications handle the errors and catch the signals, but applications that do not expect to ever run into a limit might misbehave or abort. During testing, it is a good idea to run with very tight limits and test the behavior of applications as they hit those limits. ...