System Trace 
If you want to record internal SAP system activities, use the SAP System Trace function (transaction ST01).
The system trace is primarily used when an authorization trace is required. The system log and the developer trace are recommended for system monitoring and problem analysis.
Features
The following components can be monitored using the SAP system trace:
Authorization checks
Kernel functions
Kernel modules
Database accesses (SQL trace)
Table buffers
RFC calls
HTTP calls
Lock operations (client side)
The last four components can also be monitored using performance analysis (transaction ST05). For documentation on this, see Performance Trace Overview.
There are two ways of selecting what traces you want displayed. On the initial screen, select the components to be logged and additional filters if required. You can reuse the filters and restrictions from the traces that have these settings when the traces are evaluated.
Initial Screen
The initial system trace screen looks like this:
System Trace - Initial Screen
Proceed as follows:
Switch on the trace and select the required components.
More information: Activating and Deactivating Traces
Perform the tasks that lead to the error or problem.
Switch off the trace.
Analyze the trace.
More information: Evaluating the Trace
Protecting Trace Information from Being Overwritten
If you want to protect a trace from being overwritten later, choose 
(Save) on the initial screen or choose 
Goto 
Save 
from the menu.
On the next screen, you can create a short text for a trace and choose whether the new file that is created specifically for this trace should be automatically created or whether you want to specify a file name yourself. If you do not specify an absolute path, a file of this name is created in the log directory. In the case of automatic file creation, the system determines the file name and stores the file in the log directory. The advantage of this is that, unlike a manually created file, the F4 help can be used to search for the file from the analysis screen.
Note
If you choose automatic creation, you can delete the file again in this transaction (use the 
(Delete) button on the analysis screen). This is not possible if you specify a file name. If you want to delete this kind of file, you have to do so at operating system level.
Activities
Enter transaction code ST01. Alternatively, choose Administration System Administration Monitor Traces SAP System Trace .
More Information
You can find further information in the following sections: