ULTRIX Guide to Configuration File Maintenance

This document, "ULTRIX Guide to Configuration File Maintenance" (Part Number AA-ME90D-TE, December 1991, for ULTRIX Version 4.2A or higher), serves as a comprehensive guide for managing and maintaining an ULTRIX system's kernel.

Purpose: The manual details how to build and maintain the system configuration file and subsequently build a new kernel system image, either automatically or manually.

Target Audience: It is intended for individuals responsible for managing and maintaining an ULTRIX system, who are familiar with ULTRIX commands, system configuration, device naming conventions, and a text editor (e.g., vi or ed). It explicitly states that a programming background is not required.

Key Contents:

1. Configuration Files:

   • Explains the structure and content of the system configuration file, which defines the device drivers and system parameters compiled into the kernel.
   • Differentiates between file locations for VAX (/usr/sys/conf/vax) and RISC (/usr/sys/conf/mips) processors.
   • Details the sections of the generic system configuration file, including:
     • Global Definitions: Tunable system parameters like machine, cpu, ident (system name), timezone, maxusers, physmem, bufcache, memory segment sizes, and processor count.
     • Options Definitions: Optional code to be compiled, such as support for floating-point emulation (EMULFLT), full dumps (FULLDUMPS), Internet protocols (INET), LAT, DECNET, disk quotas (QUOTA), system call tracing (SYS_TRACE), RPC, NFS, UFS, AUDIT, and Symmetric Multiprocessing (SMP).
     • Makeoptions Definitions: (Specific to RISC processors) Defines build options like byte order.
     • System Image Definitions: Configures the root device, swap areas, and dump areas for the kernel.
     • Device Definitions: Describes how to define hardware components like adapters (e.g., VAXBI, MASSBUS, UNIBUS, Q-bus, MSI, CI, IBUS), master controllers, specific device controllers (MSCP, TMSCP, SCSI), and individual devices (disks, tapes, terminals, printers).
     • Pseudodevice Definitions: Explains virtual system components without associated hardware (e.g., pty for pseudoterminals, loop for network loopback, and various network protocols).
   • Provides extensive examples of generic configuration files for both VAX and RISC processors.

2. Building the Kernel:

   • Outlines scenarios requiring a new kernel build, such as adding/removing devices or drivers, tuning the operating system, upgrading user capacity, or installing layered products.
   • Automatic Kernel Building: Describes the doconfig program, including steps like shutting down to single-user mode, saving the old kernel, copying the generic kernel, and using doconfig to prompt for system information and edit the configuration file.
   • Manual Kernel Building: Provides a step-by-step procedure: editing the configuration file, running the config utility to create build directories, defining code dependencies using make depend, compiling and loading binary files using make, and booting the new kernel.
   • Includes specific instructions for building a kernel after a capacity upgrade and for recovering the original kernel if a new one fails to boot.

3. Device Mnemonics (Appendix A):

   • Lists and defines mnemonics used by the /dev/MAKEDEV shell script to create special files and appearing in the configuration file. Categories include generic, systems, consoles, disks, tapes, terminals, modems, and printers, with explanations on how to find detailed reference page information.

In essence, the document is a practical guide for system administrators to customize and manage their ULTRIX operating system kernel by modifying its configuration files and recompiling the kernel.