StorageTek Host Software Component 6 User Manual

1st ed., 6/30/04 - 312579601

There is a hierarchy of facilities that may be used to trace the activity of the ACS service 
machine. They range from standard VM services, to SCP and HSC services. Utilities are 
also provided. 

The SCP and the HSC have separate trace facilities. Both have internal and external trace 
functions. The use of the HSC ‘‘TRACE’’ command (external trace) involves an 
interaction with the SCP ‘‘TRACE’’ command. The trace facility hierarchy involves the 
following: 

• CP trace table
• CCWTRACE 
• VM (CP) debug commands 
• SCP SET TRACE command (also, SCP TRACE) 
• SCP internal trace table 
• IPARML (IUCV parameter list) 
• IUCV interrupt buffer 
• SCP external trace facility 
• SCP Trace Formatter utility 
• Supervisor Call (SVC) functions 
• SCP GTRACE emulation 
• HSC internal trace table
• HSC TRace command. 

The CP component of VM has its own internal trace table. For the VM/SP, VM/SP HPO, 
and VM/ESA 370 feature, use the CP ‘‘CPTRAP’’ function to enable and disable event 
tracing, and the ‘‘TRAPRED’’ function to format entries. For VM/XA and VM/ESA, use 
‘‘SET CPTRACE,’’ ‘‘TRSOURCE,’’ and ‘‘TRSAVE’’ to gather trace data and 
‘‘TRACERED’’ to format it. These functions require special virtual machine 
authorization. See the appropriate VM documentation for details. 

CCWTRACE is a CP command used for I/O tracing in VM/SP, VM/SP HPO and 
VM/ESA 370. 

There are several options that control the operation of CCWTRACE. It is recommended 
that you contact StorageTek Software Support to insure that the proper CCWTRACE 
options are specified to capture the necessary data for the particular problem at hand. 

Note: For VM/XA and VM/ESA, this function is replaced by ‘‘SET CPTRACE,’’ 
‘‘TRSOURCE,’’ ‘‘TRSAVE,’’ and ‘‘TRACERED.’’