Guidelines for OpenVMS Cluster Configurations

This document, "Guidelines for OpenVMS Cluster Configurations" (January 2005), serves as a comprehensive guide for designing and optimizing OpenVMS Cluster systems. It aims to help users maximize the benefits of availability, scalability, performance, and ease of system management across various configurations. The guide applies to OpenVMS Alpha, VAX, and HP Integrity (I64) systems, including mixed-architecture clusters.

Key areas covered in the document include:

1. Overview of OpenVMS Clusters: Defines OpenVMS Clusters as a single virtual system comprising hardware (systems, interconnects, storage subsystems, adapters, peripheral devices) and software (operating system, networking, storage enhancement, system management, business applications). It highlights benefits like resource sharing, availability, scalability, and efficient management.
2. Determining Requirements: Guides users through assessing business needs (budget, availability, scalability, physical location, security) and application requirements (processing power, memory, I/O resources), and introduces various HP and partner-provided system management tools.
3. Choosing Systems: Details the supported Alpha, VAX, and HP Integrity system types (workstation to enterprise) and factors influencing selection, such as scalability, availability, and performance.
4. Selecting Interconnects: Provides a detailed comparison of various interconnect types (Ethernet, Fibre Channel, MEMORY CHANNEL, SCSI, CI, DSSI, FDDI, ATM) based on their roles (node-to-node, shared-storage, or both), throughput, and distance capabilities. It emphasizes the benefits of using multiple interconnects for failover and load balancing.
5. Choosing Storage Subsystems: Outlines criteria for selecting storage devices (capacity, I/O rate, floor space, cost) and methods for estimating storage requirements. It discusses various disk performance optimizers (e.g., DECram, solid-state disks, RAID, caching) and availability optimizers (e.g., redundant paths, volume shadowing, backup strategies) for CI-based, DSSI, SCSI, Fibre Channel, and host-based storage.
6. Advanced Configurations: Provides in-depth guidance on configuring multipath SCSI and Fibre Channel storage for enhanced availability and performance, including failover modes, device naming, and system parameters. It dedicates a full chapter to configuring Fibre Channel as a storage interconnect, covering its support, components, example configurations, addressing, naming conventions, tape support, console usage, and performance tuning.
7. Availability and Scalability Strategies: Presents detailed strategies for building and maintaining highly available OpenVMS Clusters, with specific configurations and analyses for LAN, DSSI, CI, MEMORY CHANNEL, and satellite-based clusters. It also explores advanced topics like multiple-site and disaster-tolerant cluster configurations using WAN links. For scalability, it discusses expanding in terms of CPU, memory, I/O, and storage, and optimizing I/O performance through various disk technologies and caching.
8. System Management Strategies: Offers guidelines for managing system disks (single versus multiple), environment files (common vs. multiple environments), quorum configurations, state transitions, and ensuring warranted support for mixed-version and mixed-architecture clusters.

Appendices offer supplementary technical details, installation procedures, and troubleshooting tips for SCSI, MEMORY CHANNEL, CI-to-PCI adapters (CIPCA), and multiple-site cluster systems.