DECmpp 12000/Sx Model 100 Parallel Disk Array Ref Manual

This document is the Reference Manual for the DECmpp 12000/Sx Model 100 Parallel Disk Array (PDA), published in September 1992 by Digital Equipment Corporation. It provides a comprehensive description of the PDA hardware, its installation, and service procedures.

The manual is intended for Digital Services personnel, self-maintenance customers, and PDA system administrators.

Key areas covered include:

• Parallel Disk Array Overview: Describes the PDA as a scalable, fault-tolerant hard disk storage device for massively parallel processing systems. It details the system's components (Disk Array Controller, DA Backplane, Disk Chassis, Power/Fan Tray), configurations (e.g., 5, 9, or 18 disks with capacities up to 23 Gbytes), and key interconnections.
• Installation: Provides step-by-step instructions for site preparation (physical, power, and cooling requirements), unpacking and positioning the PDA enclosure, electrical installation of Printed Circuit Boards (PCBs) and MUX PCBs, proper installation of disk canisters (including jumper and terminator settings), and connecting the PDA to the Data Parallel Unit (DPU).
• System Administration: Covers procedures for establishing communications with the PDA, configuring the disk array controller and disk banks, setting up file systems, and upgrading disk storage capacity.
• Disk Formatting: Explains various disk management commands like FORMAT (for system and user areas, managing media defects), MOUNTBANK (for initializing banks), RECONSTRUCT (for data/parity drive reconstruction and handling failed drives), SCRUB (for digital surface analysis), and SPECIFYFLAW (for specifying media defect locations).
• Removal and Replacement Procedures: Details how to remove and replace all major field-replaceable components, including controller PCBs, disk canisters, MUX PCBs, the Power/Fan tray, and various internal cables.
• Diagnostics: Describes the meaning of front panel lightpipe indicators, diagnostic procedures, and how to interpret status and error codes for troubleshooting.
• Upgrading: Provides specific instructions for expanding the disk array to configurations of 8 or 16 disk drives.

The document also includes appendices with configuration data tables, system block diagrams, a recommended spares list, disk array variations, and reference pages for the various PDA-specific commands.