HP OpenVMS Systems Documentation

Guidelines for OpenVMS Cluster Configurations

Order Number: AA--Q28LH--TK

January 2005

OpenVMS Cluster availability, scalability, and system management benefits are highly dependent on configurations, applications, and operating environments. This guide provides suggestions and guidelines to help you maximize these benefits.

Revision/Update Information: This manual supersedes Guidelines for OpenVMS Cluster Configurations Version 7.3--2.

Software Version: OpenVMS I64 Version 8.2
OpenVMS Alpha Version 8.2
OpenVMS VAX Version 7.3

Hewlett-Packard Company
Palo Alto, California

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The HP OpenVMS documentation set is available on CD-ROM.

Contents

Index

Preface

This document can help you design an OpenVMS Cluster configuration to suit your business, application, and computing needs.

It provides information to help you choose systems, interconnects, storage devices, and software. It can also help you combine these components to achieve high availability, scalability, performance, and ease of system management.

Intended Audience

This document is for people who purchase or recommend the purchase of OpenVMS Cluster products and for people who configure OpenVMS Cluster systems. It assumes a basic understanding of computers and OpenVMS Cluster concepts.

About This Guide

OpenVMS Cluster systems are designed to act as a single virtual system, even though they are made up of many components and features, as shown in Figure 1.

Figure 1 OpenVMS Cluster System Components and Features

Understanding the components and features of an OpenVMS Cluster configuration can help you to get the most out of your cluster. Table 1 shows how this guide is organized to explain these cluster concepts.

**Table 1 Document Organization**
Read...	Chapter Title	So that you can...
Chapter 1	Overview of OpenVMS Cluster System Configurations	Understand OpenVMS Cluster hardware, software, and general concepts
Chapter 2	Determining Business and Application Requirements	Learn to analyze your business and application needs and how they apply to your cluster
Chapter 3	Choosing OpenVMS Cluster Systems	Understand your computer requirements and make appropriate choices
Chapter 4	Choosing OpenVMS Cluster Interconnects	Learn about cluster interconnects and make appropriate choices
Chapter 5	Choosing OpenVMS Cluster Storage Subsystems	Learn to analyze your storage requirements and make appropriate choices
Chapter 6	Configuring Multiple Paths to SCSI and Fibre Channel Storage	Learn how to configure multiple paths to storage using Parallel SCSI or Fibre Channel interconnects, thereby increasing availability
Chapter 7	Configuring Fibre Channel as an OpenVMS Cluster Storage Interconnect	Learn how to configure an OpenVMS Cluster with Fibre Channel as a storage interconnect
Chapter 8	Configuring OpenVMS Clusters for Availability	Understand how to increase the availability of a cluster system
Chapter 9	Configuring CI OpenVMS Clusters for Availability and Performance	Learn how to use multiple components and advanced techniques to obtain high levels of availability and performance
Chapter 10	Configuring OpenVMS Clusters for Scalability	Learn how to expand an OpenVMS Cluster system in all of its dimensions, while understanding the tradeoffs
Chapter 11	OpenVMS Cluster System Management Strategies	Understand and deal effectively with some of the issues involved in managing an OpenVMS Cluster system
Appendix A	SCSI as an OpenVMS Cluster Interconnect	Configure multiple hosts and storage on a single SCSI bus so that multiple VAX and Alpha hosts can share access to SCSI devices directly
Appendix B	MEMORY CHANNEL Technical Summary	Learn why, when, and how to use the MEMORY CHANNEL interconnect
Appendix C	CI-to-PCI Adapter (CIPCA) Technical Summary	Learn why, when, and how to use the CIPCA adapter
Appendix D	Multiple-Site OpenVMS Clusters	Understand the benefits, the configuration options and requirements, and the management of multiple-site OpenVMS Cluster systems

Reader's Comments

HP welcomes your comments on this manual. Please send comments to either of the following addresses:

Internet	openvmsdoc@hp.com
Postal Mail	Hewlett-Packard Company OSSG Documentation Group, ZKO3-4/U08 110 Spit Brook Rd. Nashua, NH 03062-2698

How To Order Additional Documentation

For information about how to order additional documentation, visit the following World Wide Web address:

http://www.hp.com/go/openvms/doc/order

Conventions

VMScluster systems are now referred to as OpenVMS Cluster systems. Unless otherwise specified, references to OpenVMS Clusters or clusters in this document are synonymous with VMSclusters.

In this manual, every use of DECwindows and DECwindows Motif refers to DECwindows Motif for OpenVMS software.

The following conventions may be used in this manual:

Ctrl/ x	A sequence such as Ctrl/ x indicates that you must hold down the key labeled Ctrl while you press another key or a pointing device button.
PF1 x	A sequence such as PF1 x indicates that you must first press and release the key labeled PF1 and then press and release another key or a pointing device button.
`[Return]`	In examples, a key name enclosed in a box indicates that you press a key on the keyboard. (In text, a key name is not enclosed in a box.) In the HTML version of this document, this convention appears as brackets, rather than a box.
...	A horizontal ellipsis in examples indicates one of the following possibilities: Additional optional arguments in a statement have been omitted. The preceding item or items can be repeated one or more times. Additional parameters, values, or other information can be entered.
. . .	A vertical ellipsis indicates the omission of items from a code example or command format; the items are omitted because they are not important to the topic being discussed.
( )	In command format descriptions, parentheses indicate that you must enclose choices in parentheses if you specify more than one.
[ ]	In command format descriptions, brackets indicate optional choices. You can choose one or more items or no items. Do not type the brackets on the command line. However, you must include the brackets in the syntax for OpenVMS directory specifications and for a substring specification in an assignment statement.
\|	In command format descriptions, vertical bars separate choices within brackets or braces. Within brackets, the choices are optional; within braces, at least one choice is required. Do not type the vertical bars on the command line.
{ }	In command format descriptions, braces indicate required choices; you must choose at least one of the items listed. Do not type the braces on the command line.
bold type	Bold type represents the introduction of a new term. It also represents the name of an argument, an attribute, or a reason.
italic type	Italic type indicates important information, complete titles of manuals, or variables. Variables include information that varies in system output (Internal error number), in command lines (/PRODUCER= name), and in command parameters in text (where dd represents the predefined code for the device type).
UPPERCASE TYPE	Uppercase type indicates a command, the name of a routine, the name of a file, or the abbreviation for a system privilege.
`Example`	This typeface indicates code examples, command examples, and interactive screen displays. In text, this type also identifies URLs, UNIX commands and pathnames, PC-based commands and folders, and certain elements of the C programming language.
-	A hyphen at the end of a command format description, command line, or code line indicates that the command or statement continues on the following line.
numbers	All numbers in text are assumed to be decimal unless otherwise noted. Nondecimal radixes---binary, octal, or hexadecimal---are explicitly indicated.

Chapter 1
Overview of OpenVMS Cluster System Configuration

This chapter contains information about OpenVMS Cluster hardware and software components, as well as general configuration rules.

1.1 OpenVMS Cluster Configurations

An OpenVMS Cluster systems is a group of OpenVMS systems, storage subsystems, interconnects, and software that work together as one virtual system. An OpenVMS Cluster system can be homogeneous, that is, all systems are the same architecture (Alpha, VAX, or the HP Integrity servers (based on the Intel® Itanium® architecture)) all running OpenVMS. An OpenVMS Cluster can be heterogeneous, that is, a combination of two architectures with all systems running OpenVMS. The two valid combinations are Alpha and VAX or Alpha and HP Integrity servers based on the Intel® Itanium® architecture.

In an OpenVMS Cluster system, each system:

Shares processing resources, queues, and data storage
Can boot or fail independently
Runs the OpenVMS operating system

In addition, an OpenVMS Cluster system is managed as a single entity.

Note

In a heterogeneous cluster, only one architecture is supported per system disk and per system boot block. For more information, see Section 11.8.

Table 1-1 shows the benefits that an OpenVMS Cluster system offers.

**Table 1-1 OpenVMS Cluster System Benefits**
Benefit	Description
Resource sharing	Multiple systems can access the same storage devices, so that users can share files clusterwide. You can also distribute applications, batch, and print-job processing across multiple systems. Jobs that access shared resources can execute on any system.
Availability	Data and applications remain available during scheduled or unscheduled downtime of individual systems. A variety of configurations provide many levels of availability up to and including disaster-tolerant operation.
Flexibility	OpenVMS Cluster computing environments offer compatible hardware and software across a wide price and performance range.
Scalability	You can add processing and storage resources without disturbing the rest of the system. The full range of systems, from high-end multiprocessor systems to smaller workstations, can be interconnected and easily reconfigured to meet growing needs. You control the level of performance and availability as you expand.
Ease of management	OpenVMS Cluster management is efficient and secure. Because you manage an OpenVMS Cluster as a single system, many tasks need to be performed only once. OpenVMS Clusters automatically balance user, batch, and print work loads.
Open systems	Adherence to IEEE, POSIX, OSF/1, Motif, OSF DCE, ANSI SQL, and TCP/IP standards provides OpenVMS Cluster systems with application portability and interoperability.

1.2 Hardware Components

An OpenVMS Cluster system comprises many hardware components, such as systems, interconnects, adapters, storage subsystems, and peripheral devices. Table 1-2 describes these components and provides examples.

**Table 1-2 Hardware Components in an OpenVMS Cluster System**
Components	Description	Examples
System	A cabinet that contains one or more processors, memory, and input/output (I/O) adapters that act as a single processing body. Reference: See Chapter 3 for more information about OpenVMS systems.	OpenVMS Cluster systems can contain any supported Alpha, VAX, or HP Integrity server system.
Interconnect	The hardware connection between OpenVMS Cluster nodes over which the nodes communicate. Reference: See Chapter 4 for more information about OpenVMS Cluster interconnects.	An OpenVMS Cluster system can have one or more of the following interconnects: CI Digital Storage Systems Interconnect (DSSI) Fiber Distributed Data Interface (FDDI) MEMORY CHANNEL Small Computer Systems Interface (SCSI) Fibre Channel Ethernet, Fast Ethernet, Gigabit Ethernet ATM (asynchronous transfer mode)
Storage subsystems	Devices on which data is stored and the optional controllers that manage the devices. Reference: See Chapter 5 for more information about OpenVMS storage subsystems.	Storage subsystems can include: SCSI disks and tapes SDI, STI disks and tapes Storage array cabinets SDI/STI and SCSI storage controllers InfoServer systems
Adapter	Devices that connect nodes in an OpenVMS Cluster to interconnects and storage. Reference: See Chapter 4 for more information about adapters.	The adapters used on Peripheral Component Interconnect (PCI) systems include the following: CIPCA (CI) KFPSA (DSSI) KZPSA (SCSI) DEFPA (FDDI) DE435 (Ethernet) KGPSA (Fibre Channel) DEGPA (Gigabit Ethernet)
Peripheral devices	Devices that provide input to and produce output from a system.	Peripheral devices include: Terminals, terminal servers, and modems Printers, plotters

1.3 Software Components

OpenVMS Cluster system software can be divided into the following types:

OpenVMS operating system components
Networking components
Storage enhancement software
System management software
Business applications

1.3.1 OpenVMS Operating System Components

The operating system manages proper operation of hardware and software components and resources.

Table 1-3 describes the operating system components necessary for OpenVMS Cluster operations. All of these components are enabled by an OpenVMS operating system license or an OpenVMS Cluster license.

**Table 1-3 Operating System Components**
Component	Function
Record Management Services (RMS) and OpenVMS file system	Provide shared read and write access to files on disks and tapes in an OpenVMS Cluster environment.
Clusterwide process services	Enables clusterwide operation of OpenVMS commands, such as SHOW SYSTEM and SHOW USERS, as well as the ability to create and delete processes clusterwide.
Distributed Lock Manager	Synchronizes access by many users to shared resources.
Distributed Job Controller	Enables clusterwide sharing of batch and print queues, which optimizes the use of these resources.
Connection Manager	Controls the membership and quorum of the OpenVMS Cluster members.
SCS (System Communications Services)	Implements OpenVMS Cluster communications between nodes using the OpenVMS System Communications Architecture (SCA).
MSCP server	Makes locally connected disks to which it has direct access available to other systems in the OpenVMS Cluster.
TMSCP server	Makes locally connected tapes to which it has direct access available to other systems in the OpenVMS Cluster.

Figure 1-1 shows how the hardware and operating system components fit together in a typical OpenVMS Cluster system.

Figure 1-1 Hardware and Operating System Components