Troubleshooting z/OS MVS System Dumps

Objectives
On successful completion of this course, attendees will be able to:

• use the appropriate diagnostic procedure for each type of dump.
• identify the failing operating system component in standalone and SVC dumps
• use various operating system data-gathering facilities such as system traces, LOGREC, and SLIP.
• locate information in various manuals that is critical to problem resolution.

Who Should Attend
This course is designed for those individuals responsible for problem determination.

Duration
3 days

Course Code
MEDG

Contents
Interactive Problem Control System
Control block/data area; Information sources; Control block header; Control block data area map; Cross reference table; Fields and subfields; Field redefinitions; Control block chaining; Finding control blocks; The Prefix Area (PSA); The new Prefix Area (PSA); Dump types; IPCS introduction: what is IPCS?, What makes up IPCS?; Getting started with IPCS - Primary Option Menu; Default values selection; Primary Option Menu; Data entry panel; Pointer stack panel; Getting around in IPCS browse; IPCS subcommand entry panel; IPCS command output display; IPCS LIST command; Indirect addressing; Displaying Control Blocks; Creating SYMBOLS: Dump Directory; Additional Useful Commands; Dump analysis panel; Component Data Analysis Panel; STATUS; Analysis commands; Dump Management panel.


Recovery & Termination
MVS's recovery management; RMS; What does RTM do?; Interrupt types; Anatomy of an Interrupt; RTM - The Big Picture; How is RTM invoked?; Normal termination; Abnormal termination - problem types; Program check; Software 'Abend'; Abnormal termination - recovery; Recovery routines; RTM status information; ESPIE environment; ESPIE processing; ESTAE recovery routines; ESTAE environment; STAE Control Blocks (SCB); ESTAE processing; Percolation; Functional Recovery Routines; FRR environment; FRR stacks; RTM2WA; SDWA; Variable Recording Area; Interpreting the SDWA; Interpreting the Variable Recording Area; Logrec detail reports.


Request Block Analysis
Address space structures; RB loss of control; Linkage stacks; RB analysis procedure; Linkage Stack analysis; General analysis; RB analysis.


System Trace
Starting the System Trace; Formatting the Trace; Sequence of events; Interpreting the Trace; System Trace tips.


SVC Dump Analysis Approach
Generating SVC dumps; Dump Analysis and Elimination; Types of SVC Dump; Problem resolution overview; Dump TITLE; SDWA; History; RTM2WA; Other dumps.


Multi Processor Environments
Tightly coupled processing; Prefixing; Processor coexistence; Processor STATUS; Work In Progress; Interrupt information.


Locks
The problem; An example of what can go wrong; Serialization via LOCKS; Lock varieties; Locking Hierarchy; Locking Mechanics (SPIN); Spin Loop Identification; Spin Lock Holder; Local/CML Locks; Locking Mechanics; Global Suspend Locks ANALYZE; Locks Held; Locking Mechanics (CPU LOCK); SPIN lock summary; SUSPEND lock summary.


Dispatcher
What does it mean to be dispatched?; Where does the dispatcher run?; Dispatchable units of work; Who calls the Dispatcher?; Special exits; Service Request Block routines; Service Request Block (SRB); SRB example - IOS post; Service Request Block (SRB); Suspended Service Request Block (SSRB); SRB priorities; SRB scheduling with IEAMSCHD; SRB enclaves; Dispatcher queues; Scheduling service requests; Address spaces; ASCB/ASXB contents; Finding work within an address space - tasks; TCB contents; TCB chaining; Address space task structure; Serialization with Intersect; Dispatcher indicators; Global problem determination; Global indicators - SRB queues.


Consoles and Master Trace
Message generation; Console structure; Messages; Message Queue problems before SADump; Message queue problems after SADump; Action Messages; Master Trace; Interpreting the Master Trace; Console Component Analysis.


Input/Output Supervisor
IOS drivers; Performing I/O; I/O flow; IOS analysis - high level; Active I/O analysis; IOS failure analysis.


Real Storage Manager
Types of storage; Dynamic Address Translation; Identifying The STD; Managing real storage; RSM high level check; Detailed analysis - high fixed page utilisation; Detailed analysis - other problems; History - Component Trace.


Auxiliary Storage Manager
Paging a frame to a slot; ASM high level check; Detailed analysis: what is the problem?, who is affected?


SAD Analysis Approach
Big picture; Dump environments; When should A SADUMP be taken?; Pre SADUMP considerations; Taking a Standalone Dump; Stand Alone Dump analysis path selection; Disabled Wait analysis path; Enabled Wait Analysis path; Enabled Running Analysis path; Disabled Running Analysis path.