StorageTek Host Software Component 6 User Manual

Page of 718
366   VM/HSC 6.0 System Programmer’s Guide
1st ed., 6/30/04 - 312579601
Diagnostic Capabilities 
This section describes the overall diagnostic capabilities supported by all components of 
the HSC. Diagnostic capabilities include: 
• SCP Trace Facility.  This facility provides a history of the processing before a 
failure. 
• Supervisor Call (SVC), Dump (SDUMP), and Abnormal End (ABEND) Dumps.  
Record information on dumps is made available at the time of failure by using these 
dumps. They appear as VMDUMPS. 
• Error Recording Data Sets (ERDS).  Software failures are logged into these error 
recording data sets. 
These diagnostic tools can be helpful to you in diagnosing software problems and helpful 
when discussing any problems with StorageTek Support Services. 
SCP Trace Facility 
The SCP Trace Facility provides a low level history of the recent past. The SCP emulates 
many of the functions of the MVS GTF. The HSC issues GTRACE requests for significant 
events during operation. Format ID and Event ID (FID and EID) are specified as 
parameters on the /PARM statement of the HSC startup SLKJCL file (refer to “Creating 
an SLKJCL File for Starting the HSC” on page 157 
for more information).
Supervisor Call and Abnormal End Dumps 
SVC and ABEND dumps are taken where appropriate to diagnose software failures. 
Error Recording Data Set Records 
4480 Cartridge Subsystem and 3278 Terminal Subsystem Error Recording Dataset 
(ERDS) records are written by VM routines. The HSC writes software records to the 
ERDS to record:
• software failures for task/service request block (SRB) end 
• LSM access door opening events 
• LSM and LMU status responses 
• LMU error responses 
• control data set inaccessible 
• control data set copy inaccessible
• both journals filled 
• current journal inaccessible 
• a switch to the copy of the control data set 
• dual LMU status change in a dual LMU environment 
• a switch of the host-to-host communication method level. 
Library software uses normal ESTAE and FRR capabilities to log task/SRB termination 
records to the ERDS. Information in the variable recording area of the software record is 
used to record data pertinent to each subtype of HSC software ERDS records.