ULTRIX Guide to the Error Logger

This document, "ULTRIX Guide to the Error Logger" (Version 4.0 or higher, June 1990), provides a comprehensive overview and operational guide for the ULTRIX operating system's error logging subsystem.

The primary purpose of this subsystem is to record information about system events, including error conditions, informational messages, and application messages, in a system error logging file. This data serves as a critical tool for system management and maintenance, helping to identify the source, frequency, and type of recurrent system and hardware activity.

Key components and functionalities described include:

1. Error Logging Components:

   • Data Collection Routines: Located in device drivers, the ULTRIX kernel, and applications.
   • Memory-Resident Error Logging Buffer: Temporary storage for error log events within the kernel.
   • elcsd Daemon: Transfers error log data from the memory buffer to permanent storage in the error log file.
   • elcsd.conf File: The configuration file for the elcsd daemon, which allows users to define primary, backup, and single-user error log file paths, set file size limits, and configure remote error logging characteristics (for both server and client systems).

2. Error Logging Operation:

   • Details how error log events are initiated, temporarily stored, and then permanently logged.
   • Explains handling of data during local system crashes (requiring a savecore entry), remote system shutdowns (clients log locally), and remote system crashes (client messages may be lost).
   • Covers configuring systems for centralized error logging, where client systems send messages to a server.

3. Management and Maintenance (eli command):

   • The eli command provides manual control over error logging functions, enabling users to:
     • Enable or disable error logging.
     • Clear the kernel error log buffer.
     • Log custom messages to the error log file.
     • Restart the elcsd daemon to apply configuration changes.
     • Control error logging in single-user mode.

4. Error Report Formatter (uerf utility):

   • The uerf utility is used to interpret the binary data in the error log files and generate human-readable reports.
   • It offers various options to format reports (brief, full, terse) and filter errors based on:
     • Specific files or host systems.
     • Real-time reporting (-n).
     • Reverse chronological order.
     • Summary reports.
     • Different error types (e.g., adapter, class, disk, mainframe, operating system, tape errors).
     • Specific record types, sequence numbers, or time ranges.
     • Exclusion of certain error types.

The document is intended for system managers and Digital service representatives to effectively monitor, manage, and troubleshoot ULTRIX systems using the error logging capabilities.