VAX System Integrity Monitor (VAXsim)

This document serves as a user guide for the VAX System Integrity Monitor (VAXsim) Version 2.0, released in September 1986. It is designed for VAX/VMS system managers, providing a comprehensive tool to monitor VAX system health across stand-alone, clustered, or networked environments. VAXsim functions by tapping into the VMS error logging system, filtering relevant errors, and building a historical database for each device.

The system comprises two main components:

1. VAXsim Monitor: A detached system process that continuously collects and accumulates error and event information from the VMS error log, updating a historical database. It also signals warning conditions via OPCOM or MAIL.
2. Display Function: An interactive user interface that presents the collected data in various modes:
   • Box Mode: A five-level hierarchical tree structure (System, Subsystem, Unit, Error Classification, Error Detail), ideal for video terminals, showing error counts and severity.
   • Line Mode: A textual summary, serving as the default for hardcopy terminals.
   • Summary Mode: Lists only devices experiencing warning or alarm conditions.
   • Histogram: A graphic bar chart display (requiring ReGIS-compatible terminals) that visualizes error trends over time.

VAXsim organizes system errors into device errors (Hard, Soft, Media, Informational) and events (non-errors like system boots). It evaluates error rates by comparing current error counts to historical performance, using "Clipping" to moderate the impact of sudden error bursts and a "Margin" factor to account for normal fluctuations before triggering warning or alarm indicators.

Key updates in Version 2.0 include a requirement for VMS Version 4.2 or later, enhanced support for VAXcluster configurations with a single globally-accessible database, new Histogram and Summary display modes, a dedicated status display, and an autocorrection facility for mistyped commands. The user interface also incorporates keypad commands and supports VMS electronic mail for error notifications. Commands for managing the display database, adjusting evaluation periods (Absolute and Delta Time), and generating reports are detailed, alongside technical notes on VAXsim's algorithms and software components.