Note: In AIX Version 4, the trace facility subsystem is stored in an option package entitled Software Trace Service Aids (bos.sysmgt.trace). Although the base system includes minimal services for trace (including the trcstart, trcstop, trcon, and trcoff subroutines, and the trcupdate command), you need to install the Software Trace Service Aids package to activate the trace daemon and produce trace reports.
The trace facility helps you isolate system problems by monitoring selected system events. Events that can be monitored include: entry and exit to selected subroutines, kernel routines, kernel extension routines, and interrupt handlers. The trace facility captures a sequential flow of system events, providing a fine level of detail on system activity. Events are shown in time sequence and in the context of other events. The trace facility is useful in expanding the trace event information to understand who, when, how, and even why the event happened.
When the trace facility is active, information about system events is recorded in a system trace log file. The trace facility includes commands for activating and controlling traces and generating trace reports. Applications and kernel extensions can use several subroutines to record additional events.
Use the following procedures to activate the trace facility: