z/OS Diagnostics & Debugging

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

• report problems and communicate with applications personnel and systems programmers
• understand what MVS''s Recovery Termination Manager (RTM) does when programs fail
• understand the concept of an ABEND
• analyze ABEND-situations
• 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 suitable for all Systems Programmers working in the zSeries Server environment.
Prerequisites
To benefit from this course, participants need: the ability to read Assembler code, familiarity with MVS internal operations and data areas, including the concept of control block chaining. These prerequisites can be met by completing the RSM courses Using z/OS Assembler, z/OS MVS System Fundamentals Workshop - Part 1 and z/OS MVS System Fundamentals Workshop - Part 2.
Duration
5 days
Course Code
ZDIA
Contents
z/OS MVS software environment
The z/OS environment - a lot of programs; three software categories; the mission of an Operating System; workload in MVS; asking for MVS services; asynchronous MVS activities; asynchronous "unwelcome" MVS activities; summary; review questions.


Recovery Termination Manager (RTM)
Normal Program Termination; EXIT (SVC 3); abnormal program termination; Program Checks; system forced ABEND; program ABEND; why abnormal termination?; logical application error; program incomplete; application detected software error; system detected software error; hardware detected software error; PC FLIH and ABENDs; hardware detected software error example; Program Checks in the Supervisor; hardware problems; RTM actions; recovery; Functional Recovery Routines (FRRs); Extended Specify Task Abnormal Exit (ESTAE); system breakdown; software problem types; review questions.


MVS error reporting & dumps
System error reporting; MVS dumps; Stand-Alone Dump (SADUMP); SVC dumps; user ABEND dumps; SYSUDUMP; SYSABEND; SYSMDUMP; CEEDUMP; generating a user ABEND dump; system generated ABEND dump; snap dumps; symptom dumps; review questions.


ABEND analysis
What is ABEND?; the MVS ABEND service; why ABEND?; allows for recovery routines ; task termination; tasks in an Address Space; how RTM is invoked; program checks; ABEND; how to trigger an ABEND; ABEND macro and SVC 13; CALLRTM macro; why not normal end?; application detected software errors; system detected software errors; all the system ABEND codes; where do you see the ABEND codes?; the NOTIFY message; the SYSLOG; the job log; the symptom dump; ABEND dumps; SVC dumps; Stand-Alone dumps; the symptom dump in the SYSLOG; the symptom dump in the job log; explanations of ABEND and reason codes; IBM z/OS manuals on the web; Quickref and similar tools; analysis approach; examples of ABEND code explanation; system messages - a good information source; system message prefix; message level; standard message types; alternative message types; message identifier and MVS components; examples of system messages; explanation of system messages; common system ABEND codes; system ABEND code numbers; common SVCs and their macros; the x22 codes - caused by outside events; the x13 codes - OPEN problems; other x13 codes; example of S013-18; 806 - Program not found; sequence of events; example of S806-04; 804, 80A, 878, 878 and DC2 - virtual storage problems; the Virtual Address Space; "above the bar"; traditional address space areas; the need for managing virtual storage; storage for the program code; storage obtained outside the program; Virtual Storage requests; limitations on Virtual Storage; ABEND and reason codes; requests for storage below 2 GB (GETMAIN and STORAGE OBTAIN); requests for storage above 2 GB (IAR64 GETSTOR); the REGION limit; the effects of different REGION values; example of ABEND S822; the MEMLIMIT parameter; example of ABEND SDC2; the 0Cx codes; the Program Check Interrupt; running RTM1; PC FLIH and ABENDs; the meaning of Program Checks; common ABENDs from Program Checks; ABEND S0C4; Storage Protect Keys; virtual address protection; reasons for translation exceptions; address truly invalid; address valid - new area; address valid - old area; other S0Cx ABENDs; PIC 0001 Operation Exception (ABEND S0C1); PIC 0002 Privileged Operation Exception (ABEND S0C2); PIC 0007 Data Exception (ABEND S0C7); the S0E0 and 0Dx codes; miscellaneous problems; problems with translations; Linkage Stack problems; the Sx37 and SB14 codes; Sx37; EOV processing; how disk data sets are allocated; Physical Sequential (PS) data sets; problems when allocating a PS data set; initial allocation; primary allocation failure; data set full; no secondary allocation (SD37-04); secondary allocations (SB37-04); example of unavailable primary allocation; example of SD37-04; message IEC031I; example of ABEND SB37-04; message IEC030I; Partitioned Data Sets (PDS); problems when allocating a PDS; initial allocation; data set full; no secondary allocation (SD37-04); secondary allocations (SE37-04); directory full (SB14-0C); example of ABEND SE37-04; message IEC032I; example of ABEND SB14; message IEC217I; Partitioned Data Sets Extended (PDSE); problems when allocating a PDSE; summary of common system ABEND codes; other ABEND codes; MVS system codes (Sxxx); user ABEND codes (Uxxxx).


IPCS



RTM and software Logrec



RB analysis



System Trace



SVC dump approach



MP environments



Locks



Dispatcher



Consoles and Master Trace



Storage Managers