OpenVMS VAX System Dump Analyzer Utility Manual

This document is a user manual for the OpenVMS VAX System Dump Analyzer (SDA) Utility, version 7.3, published in April 2001 by Compaq Computer Corporation.

Purpose: The SDA utility is designed to:

• Investigate system failures (crash dumps): It helps system programmers and managers determine the causes of system crashes by interpreting the contents of system dump files, examining the state of processors at the time of failure, and debugging kernel-mode code (like device drivers).
• Examine a running system: It can be used to diagnose performance issues or "hung" processes without disturbing the operating system.

Key Features and Usage:

• Invocation: SDA is invoked using DCL commands: ANALYZE/CRASH_DUMP for dump files or ANALYZE/SYSTEM for a running system.
• Dump File Management: Covers understanding system dump files (SYSDUMP.DMP and PAGEFILE.SYS), calculating their appropriate size, and saving/freeing dump file space.
• Analysis Process: Details how SDA maps dump file contents, builds symbol tables (defaulting to SYS$SYSTEM:SYS.STB and REQSYSDEF.STB), and executes initialization files (SDA$INIT).
• Context Management: Explains SDA's process and CPU contexts and how to change them using SET PROCESS and SET CPU commands.

• Commands: Provides a comprehensive list and detailed descriptions of SDA commands for:

  • Information Display: SHOW CRASH, SHOW CPU, SHOW STACK, SHOW SUMMARY, SHOW DEVICE, SHOW EXECUTIVE, SHOW CLUSTER, SHOW CONNECTIONS, SHOW LOCK, SHOW LOGS, SHOW PAGE_TABLE, SHOW PFN_DATA, SHOW POOL, SHOW PORTS, SHOW PROCESS, SHOW RESOURCE, SHOW RMS, SHOW RSPID, SHOW SPINLOCKS, SHOW SYMBOL.
  • Memory Examination: EXAMINE (including specific qualifiers like /INSTRUCTION, /PSL, /PTE), SEARCH.
  • Expression Evaluation: EVALUATE.
  • Utility Management: ATTACH, COPY, DEFINE (for symbols and keys), READ (for symbol tables), REPEAT, SPAWN, SET LOG, SET OUTPUT, EXIT.
  • Integrity Checks: VALIDATE QUEUE.

• System Failure Investigation: Offers a general procedure for diagnosing errors, specifically addressing fatal bugcheck conditions (exceptions, illegal page faults) and provides a sample system failure analysis.

• Inducing System Failures: Includes instructions and console commands for deliberately causing a system failure, useful for testing crash dump mechanisms.

Intended Audience: Primarily for system programmers investigating system failures and debugging kernel-mode code, but also contains essential information for system managers responsible for crash dump configuration and for those needing to analyze running systems to troubleshoot performance or hung processes.