XFRB Command: Trace Slot I/O Events

Commands › XFRB Command: Trace Slot I/O Events

XFRB Command: Trace Slot I/O Events

To trace slot I/O events and send the trace data to a sysout data set, use the XFRB command.

Note: XFRB is a diagnostic tool. Do not use under normal operating conditions.

Type: OPER command

Authority: To issue the XFRB command, you require OPER authority.

This command has the following format:

XFRB SET|T TRACE|TR
     [SYSOUT(class)]|[LOGTRACE]
     [ASYNC|ALL]
     [LOCK|NOLOCK]
     [RESERVE|NORESERVE]

XFRB {START|S}
     {STOP|P}
     {RESTART|RES|RS|SPIN|SP}
     {DISPLAY|D}
     TRACE|TR

XFRB HELP|H|?

SYSOUT(class): Send slot I/O trace data to a sysout data set with DDNAME FRBTRACE and to the class that class specifies.
LOGTRACE: Send slot I/O trace data to a sysout data set with DDNAME LOGTRACE. The trace data is consolidated with certain other trace data.
ASYNC: Include only asynchronous slot I/Os in the trace data.
ALL: Include asynchronous and synchronous slot I/Os in the trace data.
LOCK: Include internal slot data set locking and unlocking events in the trace data.
NOLOCK: Exclude internal slot data set locking and unlocking events from the trace data.
RESERVE: Include slot data set cross-system serialization events in the trace data.
NORESERVE: Exclude slot data set cross-system serialization events from the trace data.
START|S: Start the slot I/O tracing.
STOP|P: Stop the slot I/O tracing.
RESTART|RES|RS|SPIN|SP: Stop and restart the slot I/O tracing.
DISPLAY|D: Display the current XFRB status.
HELP|H|?: Display the XFRB command operands.

Set Up the Trace

Do this task before you start the trace. Set up the trace by issuing XFRB with at least the SYSOUT or LOGTRACE operands. If you issue XFRB with the LOGTRACE operand, set up the trace data consolidation.

Start Trace Data Consolidation

When you specify the LOGTRACE operand, data for the XFRB trace is not generated. Additionally, data for the XFRB trace is not consolidated with data from other traces until you start the XFRB trace and start trace consolidation.

Displaying Trace Settings

Issue XFRB SET TRACE alone to display the current settings for the XFRB tracing.

Asynchronous I/Os

Some slot data set I/Os, such as the TRAKFILE I/Os, are asynchronous for performance reasons. z/OS Agent main task is not suspended when a wait is required for an asynchronous I/O completion.

Related Information

See the XFRB initialization parameter in the Initialization and Configuration Guide.
See the LOGTRACE Command.

Example: Display the Current Settings for XFRB Tracing

These two examples show how to display XFRB trace settings.

XFRB DISPLAY TRACE
XFRB D TR

Example: Set the Sysout Class for XFRB Trace Data

This example shows how to specify that trace data goes to DDNAME FRBTRACE with the sysout class set to A.

XFRB SET TRACE SYSOUT(A)

Example: Consolidate XFRB Trace Data with Other Trace Data

This example shows how to specify that trace data goes to the DDNAME LOGTRACE, and the trace data is consolidated with certain other trace data.

XFRB SET TRACE LOGTRACE

Example: Filter XFRB Trace Data

This example shows how to limit the trace data to the asynchronous slot I/Os and include slot data set cross-system serialization events in the trace.

XFRB SET TRACE ASYNC RESERVE

Example: Control the XFRB Trace

This example shows how to start the XFRB trace.

XFRB START TRACE

This example shows how to restart the XFRB trace.

XFRB SP TRACE

Example: Get Help

This example shows how to display the operands for the XFRB command.

XFRB ?