Alpha AXP DSSI VMScluster Installation and Troubleshooting Guide

This guide provides comprehensive instructions for installing and maintaining DSSI VMScluster configurations with Alpha AXP systems (specifically Digital 2100 Server and DEC 4000 AXP systems), and also covers dual-architecture clusters with VAX systems. It is intended for experienced system administrators familiar with OpenVMS AXP and VAX operating systems.

The document details two primary cluster types: AXP-only and dual-architecture (AXP and VAX), outlining their capabilities and various restrictions, such as the number of DSSI nodes per bus (up to eight), limitations on tape serving for AXP processors, and SCSI bus naming conventions that affect drive visibility. It specifies software and licensing requirements (OpenVMS AXP 6.1, OpenVMS VAX 5.5-2, DECnet) and critical physical requirements including maximum DSSI bus lengths (20-25m) and the necessity of maintaining a common ground across all enclosures to prevent data corruption.

Installation involves a nine-step hardware setup process, including configuring bus node IDs for host adapters (using ECU for KFESA or NCRn_SETUP for DEC 4000 AXP) and HSD05 array controllers, connecting ground and DSSI cables, setting DSSI device parameters (Allocation Class, Unit Number, Node Name) via console commands (cdp or set host -dup -dssi for HSD05), configuring SCSI node ID plugs to ensure unique device names, and setting boot parameters. The guide emphasizes the importance of unique node IDs and proper bus termination.

Finally, a dedicated troubleshooting section addresses common hardware problems like missing drives, duplicate node IDs, loose cables, and termination issues, providing specific symptoms and corrective actions for both Digital 2100 Server and DEC 4000 AXP systems. Appendices offer details on electrical lengths of embedded DSSI interconnects and how OpenVMS AXP utilizes DSSI device parameters for device identification.