ULTRIX-32 Guide to System Disk Maintenance

This document, "ULTRIX-32 Guide to System Disk Maintenance" (Version 3.0, 1987/1988), serves as a practical guide for managing and maintaining disk space on ULTRIX-32 operating systems. It is intended for system administrators familiar with ULTRIX-32 commands and system configuration.

The guide covers three primary areas:

1. System Disks and File System Organization: It provides background on disk organization (sectors, partitions) and default system disk configurations. It explains the concepts of paging and swapping, how to allocate swap space, and details the ULTRIX File System (UFS) structure, including sharable and non-sharable data, and the setup of key system and user directories (e.g., /var, /usr/users).
2. Managing Disk Space: It outlines methods for monitoring disk usage, such as checking available free space using the df command, checking disk use with du -s, and verifying disk quotas with quot. It also describes strategies for obtaining additional disk space by deleting files or moving file systems and files.
3. Disk Partitioning and Bad Block Replacement:
   • Disk Partitioning: It provides step-by-step procedures for changing partition sizes using the chpt command, emphasizing necessary preparations like assessing space needs, analyzing performance, and backing up data. It explains the ULTRIX disk partitioning scheme and rules for modifying partition tables.
   • Bad Block Replacement: It describes how ULTRIX-32 handles bad blocks on DIGITAL Storage Architecture (DSA) disks, covering automatic (controller-initiated, host-initiated, media replacement) and manual methods. It explains how to interpret disk error messages from the errorlog file and details the radisk utility for manually clearing, replacing, or scanning blocks, as well as procedures for forced error recovery and data restoration.

An appendix provides a reference for Device Mnemonics used in system configuration and for creating special device files.

Overall, the document equips administrators with the knowledge and tools to effectively monitor, reconfigure, and troubleshoot disk storage to optimize system performance and maintain data integrity on ULTRIX-32 systems.