ULTRIX-32 Guide to System Configuration File Maintenance

This document, the "ULTRIX-32 Guide to System Configuration File Maintenance (Order No. AA-ME90A-TE)," for ULTRIX-32 Operating System, Version 3.0, serves as a guide for system administrators responsible for managing and maintaining ULTRIX systems. It assumes familiarity with ULTRIX commands, system configuration, and text editors, but does not require programming knowledge.

The guide covers two primary areas:

1. The System Configuration File:

   • Explains that the system configuration file describes how to build the kernel, identifying device driver source code and system parameters. It typically resides in /usr/sys/conf.
   • Details the four main parts of a configuration file:
     • Global Definitions: Tunable system parameters (e.g., machine type, CPU, timezone, max users, memory allocation).
     • System Image Definitions: Defines root device, swap areas, and crash dump areas for the kernel.
     • Device Definitions: Describes current or planned hardware devices (adapters, masters, controllers, disks, tapes) and their connections.
     • Pseudodevice Definitions: Defines operating system components without associated hardware (e.g., network protocols, pseudoterminals).
   • Includes specific information for diskless client configuration files, noting their naming conventions and differences (e.g., root is always an Ethernet device) and strongly advises not modifying supplied default diskless configuration files.

2. Building the Kernel:

   • Outlines the reasons for building a new kernel, such as adding or deleting devices, tuning the operating system, performing capacity upgrades, or adding layered products (like DECnet).
   • Provides procedures for building a kernel:
     • Automatically: Using the /etc/doconfig program, which prompts for system information and automatically generates the kernel.
     • Manually: A multi-step process involving editing the configuration file, preparing the directory for binary files, defining code dependencies, compiling and loading the binary files, and then booting the new kernel.
     • After a Capacity Upgrade Installation: Primarily uses the doconfig command, with specific instructions for updating the maxusers parameter.
   • Emphasizes saving the original kernel for recovery purposes in case the new kernel fails to boot or encounters errors.

Additionally, an appendix lists Device Mnemonics used in configuration files and by the MAKEDEV utility, providing brief descriptions and advising on how to obtain more detailed reference page information.