Subsystem Control Point (SCP) Management Programming Manual

Tr ac ing
Subsystem Control Point (SCP) Management Programming Manual—520619-001
B-7
Tracing to Disk
Resolving a File-Full Condition
The value of ZTRC-DDL-TRACE-MODIF.ZWRAP specifies how the file-full condition
for the trace file is resolved:
Figure B-4. A Tracing Process Overtakes a Collector Process
ZSPI-VAL-FALSE or blank When the disk file becomes full, the trace is stopped
(default value).
ZSPI-VAL-TRUE When the disk file becomes full, new data is writeen over
the old data (the file wraps).
Extended Data Segment
VST040.vsd
Trace Records Wrap to Beginning of Segment
New Records
Written Over
Old by Tracing
Process
Old
Records
Already
Written to
Disk by
Collector
Records Written by
Tracing Process
Start of Next Block to
Be Written to Disk