Compaq 9900 User Manual

Hitachi Freedom Storage™

Lightning 9900™

User and Reference Guide

© 2003 Hitachi Data Systems Corporation, ALL RIGHTS RESERVED

Notice: No part of this publication may be reproduced or transmitted in any form or by any
electronic or mechanical means, including photocopying and recording, or stored in a
database or retrieval system for any purpose, without the express written permission of
Hitachi Data Systems Corporation.

Hitachi Data Systems reserves the right to make changes to this document at any time
without notice and assumes no responsibility for its use. Hitachi Data Systems products and
services can only be ordered under the terms and conditions of Hitachi Data Systems’
applicable agreements, including license agreements. All of the features described in this
document may not be currently available. Refer to the most recent product announcement
or contact your local Hitachi Data Systems sales office for information on feature and
product availability.

This document contains the most current information available at the time of publication.
When new and/or revised information becomes available, this entire document will be
updated and distributed to all registered users.

Trademarks

Hitachi Data Systems is a registered trademark and service mark of Hitachi, Ltd. The Hitachi
Data Systems design mark is a trademark and service mark of Hitachi, Ltd.

Hi-Track is a registered trademark of Hitachi Data Systems Corporation.

Extended Serial Adapter, ExSA, Hitachi Freedom Storage, Hitachi Graph-Track, and Lightning
9900 are trademarks of Hitachi Data Systems Corporation.

APC and Symmetra are trademarks or registered trademarks of American Power Conversion
Corporation.

HARBOR is a registered trademark of BETA Systems Software AG.

AIX, DYNIX/ptx, ESCON, FICON, IBM, MVS, MVS/ESA, VM/ESA, and S/390 are registered
trademarks or trademarks of International Business Machines Corporation.

Microsoft, Windows, and Windows NT are registered trademarks of Microsoft Corporation.

Tantia is a trademark of Tantia Technologies Inc. Tantia Technologies is a wholly owned
subsidiary of BETA Systems Software AG of Berlin.

All other brand or product names are or may be registered trademarks, trademarks or
service marks of and are used to identify products or services of their respective owners.

Notice of Export Controls

Export of technical data contained in this document may require an export license from the
United States government and/or the government of Japan. Contact the Hitachi Data
Systems Legal Department for any export compliance questions.

Hitachi Lightning 9900™ User and Reference Guide iii

Document Revision Level

Revision Date Description

MK-90RD008-0 July 2000 Initial Release

MK-90RD008-1 November 2000 Revision 1, supersedes and replaces MK-90RD008-0

MK-90RD008-2 March 2001 Revision 2, supersedes and replaces MK-90RD008-1

MK-90RD008-3 June 2001 Revision 3, supersedes and replaces MK-90RD008-2

MK-90RD008-4 January 2002 Revision 4, supersedes and replaces MK-90RD008-3

MK-90RD008-5 February 2002 Revision 5, supersedes and replaces MK-90RD008-4

MK-90RD008-6 May 2002 Revision 6, supersedes and replaces MK-90RD008-5

MK-90RD008-7 October 2003 Revision 7, supersedes and replaces MK-90RD008-6

Source Documents for this Revision

This document revision applies to 9900 microcode versions 01-12-xx.

This document revision applies to 9900 microcode versions 01-13-xx.

This document revision applies to 9900 microcode versions 01-16-xx.

This document revision applies to 9900 microcode versions 01-17-xx.

This document revision applies to 9900 microcode versions 01-17-yy.

This revision applies to 9900 microcode versions 01-18-67 and higher.

 DKC410I/405I Disk Subsystem Maintenance Manual, revision 12.1 (August 2003).

 RAID400_RAID450_Public_Mode_Rev.2a (April 29, 2003).

Changes in this Revision

 Updated description of disk drive and cache upgrades to remove the statement that all

upgrades can be made with minimal impact (section 1.1.7).

 Added information on the 146-GB hard disk drive (sections 2.3, 2.4.2, 2.4.3; Table 2.2,

Table 2.3, Table 5.8, Table 5.9, Table 5.18).

 Added information on the public system option modes (new section 3.5, new Table 3.2-

Table 3.8).

iv Preface

Preface

This document describes the physical, functional, and operational characteristics of the
Hitachi Lightning 9900™ subsystem, provides general instructions for operating the 9900
subsystem, and provides the installation and configuration planning information for the 9900
subsystem.

This document assumes that:

 The user has a background in data processing and understands direct-access storage

 The user is familiar with the S/390

 The user is familiar with the equipment used to connect RAID disk array subsystems to

For further information on Hitachi Data Systems products and services, please contact your
Hitachi Data Systems account team, or visit Hitachi Data Systems worldwide web site at

http://www.hds.com

the Lightning 9900™ subsystem, please refer to the 9900 user documentation for the
platform, or contact the Hitachi Data Systems Support Center.

device (DASD) subsystems and their basic functions,

®

(mainframe) operating systems and/or open-system

platforms supported by the 9900 subsystem, and

the supported host systems.

. For specific information on supported host systems and platforms for

Note: Unless otherwise noted, the term “9900” refers to the entire Hitachi Lightning 9900™
subsystem family, including all models (e.g., 9960, 9910) and all configurations (e.g., all­mainframe, all-open, multiplatform).

Note: The use of Hitachi Data Systems products is governed by the terms of your license
agreement(s) with Hitachi Data Systems.

Microcode Level

This document revision applies to 9900 microcode versions 01-18-67 and higher.

Please send us your comments on this document: [e-mail].

Make sure to include the document title, number, and revision.

Please refer to specific page(s) and paragraph(s) whenever possible.

(All comments become the property of Hitachi Data Systems Corporation.)

COMMENTS

Thank you!

Hitachi Lightning 9900™ User and Reference Guide v

vi Preface

Contents

Chapter 1 Overview of the Lightning 9900™ Subsystem

1.1 Key Features of the Lightning 9900™ Subsystem............................ 1

1.1.1 Continuous Data Availability..................................... 2

1.1.2 Connectivity.................................................. 2

1.1.3 S/390® Compatibility and Functionality............................. 3

1.1.4 Open-Systems Compatibility and Functionality....................... 3

1.1.5 Hitachi Freedom NAS™ and Hitachi Freedom SAN™.................... 4

1.1.6 Program Products and Service Offerings............................ 6

1.1.7 Subsystem Scalability........................................... 8

1.2 Reliability, Availability, and Serviceability................................ 9

Chapter 2 Subsystem Architecture and Components

2.1 Overview ..........................................................11

2.2 Components of the Controller Frame ....................................14

2.2.1 Storage Clusters...............................................14

2.2.2 Nonvolatile Shared Memory......................................15

2.2.3 Nonvolatile Duplex Cache .......................................15

2.2.4 Multiple Data and Control Paths ..................................16

2.2.5 Redundant Power Supplies.......................................16

2.2.6 Client-Host Interface Processors (CHIPs) and Channels.................16

2.2.7 Channels ....................................................18

2.2.8 Array Control Processors (ACPs) ..................................19

2.3 Array Frame........................................................21

2.3.1 Disk Array Groups..............................................23

2.3.2 Sequential Data Striping ........................................24

2.4 Intermix Configurations...............................................25

2.4.1 RAID-1 & RAID-5 Intermix........................................25

2.4.2 Hard Disk Drive Intermix ........................................25

2.4.3 Device Emulation Intermix.......................................26

2.5 Service Processor (SVP)...............................................27

2.6 Remote Console PC ..................................................27

Chapter 3 Functional and Operational Characteristics

3.1 New 9900 Features and Capabilities .....................................29

3.2 I/O Operations......................................................29

3.3 Cache Management ..................................................30

3.3.1 Algorithms for Cache Control.....................................30

3.3.2 Write Pending Rate ............................................30

3.4 Control Unit (CU) Images, LVIs, and LUs..................................31

3.4.1 CU Images ...................................................31

3.4.2 Logical Volume Image (LVIs) .....................................31

3.4.3 Logical Unit (LU) Type..........................................31

3.5 System Option Modes.................................................32

Hitachi Lightning 9900™ User and Reference Guide vii

3.6

Open Systems Features and Functions................................... 37

3.6.1 Failover and SNMP Support...................................... 37

3.6.2 Share-Everything Architecture................................... 37

3.6.3 SCSI Extended Copy Command Support ............................ 37

3.7 Data Management Functions .......................................... 38

3.7.1 Hitachi TrueCopy (TC) ......................................... 40

3.7.2 Hitachi TrueCopy – S/390® (TC390) ............................... 40

3.7.3 Hitachi ShadowImage (SI)....................................... 41

3.7.4 Hitachi ShadowImage – S/390® (SI390)............................. 41

3.7.5 Command Control Interface (CCI) ................................ 42

3.7.6 Extended Copy Manager (ECM)................................... 42

3.7.7 Hitachi Extended Remote Copy (HXRC)............................ 43

3.7.8 Hitachi NanoCopy™............................................ 44

3.7.9 Data Migration ............................................... 44

3.7.10 Hitachi RapidXchange (HRX)..................................... 45

3.7.11 Hitachi Multiplatform Backup/Restore (HMBR) ...................... 45

3.7.12 HARBOR® File-Level Backup/Restore.............................. 46

3.7.13 HARBOR® File Transfer......................................... 46

3.7.14 HiCommand™ ................................................ 46

3.7.15 LUN Manager ................................................ 47

3.7.16 LU Size Expansion (LUSE)....................................... 47

3.7.17 Virtual LVI/LUN .............................................. 47

3.7.18 FlashAccess.................................................. 48

3.7.19 Cache Manager............................................... 48

3.7.20 Hitachi SANtinel.............................................. 49

3.7.21 Hitachi SANtinel – S/390®....................................... 49

3.7.22 Prioritized Port and WWN Control (PPC) ........................... 50

3.7.23 Hitachi Parallel Access Volume (HPAV) ............................ 50

3.7.24 Dynamic Link Manager™ (DLM)................................... 50

3.7.25 LDEV Guard.................................................. 50

3.7.26 Hitachi CruiseControl.......................................... 51

3.7.27 Hitachi Graph-Track™.......................................... 52

Chapter 4 Configuring and Using the 9900 Subsystem

4.1 S/390® Configuration ................................................ 53

4.1.1 Subsystem IDs (SSIDs) .......................................... 53

4.2 S/390® Hardware Definition........................................... 54

4.2.1 Hardware Definition Using IOCP (MVS, VM, or VSE)................... 54

4.2.2 Hardware Definition Using HCD (MVS/ESA) ......................... 59

4.2.3 Defining the 9900 to VM/ESA® Systems ............................ 70

4.2.4 Defining the 9900 to TPF....................................... 70

4.3 S/390® Operations .................................................. 71

4.3.1 Initializing the LVIs............................................ 71

4.3.2 Device Operations: ICKDSF...................................... 71

4.3.3 MVS Cache Operations......................................... 73

4.3.4 VM/ESA® Cache Operations ..................................... 75

4.3.5 VSE/ESA Cache Operations...................................... 75

viii Contents

4.4

Open-Systems Configuration ...........................................76

4.4.1 Configuring the Fibre-Channel Ports...............................77

4.4.2 Virtual LVI/LUN Devices.........................................77

4.4.3 LU Size Expansion (LUSE) Devices .................................77

4.5 Open Systems Operations .............................................78

4.5.1 Command Tag Queuing .........................................78

4.5.2 Host/Application Failover Support.................................78

4.5.3 Path Failover Support ..........................................79

4.5.4 Remote SIM (R-SIM) Reporting....................................80

4.5.5 SNMP Remote Subsystem Management .............................80

4.5.6 NAS and SAN Operations ........................................80

Chapter 5 Planning for Installation and Operation

5.1 User Responsibilities .................................................81

5.2 Electrical Specifications and Requirements for Three-Phase Subsystems.........82

5.2.1 Internal Cable Diagram .........................................82

5.2.2 Power Plugs..................................................83

5.2.3 Features.....................................................84

5.2.4 Current Rating, Power Plug, Receptacle, and Connector for

Three-Phase (60 Hz only)........................................84

5.2.5 Input Voltage Tolerances........................................85

5.3 Electrical Specifications and Requirements for Single-Phase Subsystems.........86

5.3.1 Internal Cable Diagram .........................................86

5.3.2 Power Plugs..................................................88

5.3.3 Features.....................................................91

5.3.4 Current Rating, Power Plug, Receptacle, and Connector for

Single-Phase (60 Hz only)........................................91

5.3.5 Input Voltage Tolerances........................................92

5.4 Dimensions and Weight ...............................................93

5.5 Floor Loading and Cable Routing Requirements ............................96

5.5.1 Service Clearance Requirements..................................96

5.5.2 Minimum Subsystem Disk Configuration............................101

5.5.3 Floor Load Rating.............................................105

5.5.4 Cable Requirements...........................................109

5.6 Channel Specifications and Requirements................................110

5.7 Environmental Specifications and Requirements...........................111

5.7.1 Temperature and Humidity Requirements..........................111

5.7.2 Power Consumption and Heat Output Specifications..................111

5.7.3 Loudness ...................................................113

5.7.4 Air Flow Requirements.........................................113

5.7.5 Vibration and Shock Tolerances..................................114

Hitachi Lightning 9900™ User and Reference Guide ix

Chapter 6 Troubleshooting

6.1 Troubleshooting................................................... 115

6.2 Service Information Messages (SIMs) ................................... 116

6.3 Calling the Hitachi Data Systems Support Center ......................... 117

Appendix A Unit Conversions

...................................................... 119

Acronyms and Abbreviations....................................................... 121

x Contents

List of Figures

Figure 2.1 Lightning 9900™ HiStar Network (HSN) Architecture .....................11

Figure 2.2 9960 Subsystem Frames...........................................13

Figure 2.3 9910 Subsystem Frame ...........................................13

Figure 2.4 Conceptual ACP Array Domain......................................19

Figure 2.5 Sample RAID-1 Layout ............................................23

Figure 2.6 Sample RAID-5 Layout (Data Plus Parity Stripe) ........................24

Figure 2.7 Sample Hard Disk Drive Intermix....................................25

Figure 2.8 Sample Device Emulation Intermix ..................................26

Figure 3.1 Fibre-Channel Device Addressing....................................31

Figure 4.1 IOCP Definition for FICON™ Channels (direct connect and via

Figure 4.2 IOCP Definition for 1024 LVIs (9900 connected to host CPU(s) via ESCD) .....56

Figure 4.3 IOCP Definition for 1024 LVIs (9900 directly connected to CPU)............57

Figure 4.4 Master MENU (Step 1) ............................................61

Figure 4.5 Basic HCD Panel (Step 2)..........................................62

Figure 4.6 Define, Modify, or View Configuration Data (Step 3) ....................62

Figure 4.7 Control Unit List Panel (Step 4).....................................63

Figure 4.8 Add Control Unit Panel (Step 5) ....................................63

Figure 4.9 Selecting the Operating System (Step 6)..............................64

Figure 4.10 Control Unit Chpid, CUADD, and Device Address Range Addressing (Step 7) . . 64

Figure 4.11 Select Processor / Control Unit Panel (Step 8).........................65

Figure 4.12 Control Unit List (Step 9)..........................................65

Figure 4.13 I/O Device List Panel (Step 10).....................................66

Figure 4.14 Add Device Panel (Step 11)........................................66

Figure 4.15 Device / Processor Definition Panel – Selecting the Processor ID (Step 12) ...67

Figure 4.16 Define Device / Processor Panel (Step 13) ............................67

Figure 4.17 Device / Processor Definition Panel (Step 14) .........................68

Figure 4.18 Define Device to Operating System Configuration (Step 15)...............68

Figure 4.19 Define Device Parameters / Features Panel (Step 16) ...................69

Figure 4.20 Update Serial Number, Description and VOLSER Panel (Step 18) ...........69

Figure 4.21 LVI Initialization for MVS: ICKDSF JCL................................71

Figure 4.22 Displaying Cache Statistics Using MVS DFSMS ..........................73

Figure 4.23 IDCAMS LISTDATA COUNTS (JCL example).............................73

Figure 4.24 Fibre Port-to-LUN Addressing ......................................77

Figure 4.25 Alternate Pathing ...............................................79

FICON™ switch) .................................................55

Figure 5.1 Diagram of Power Plugs for Three-Phase 9960 Disk Array Unit (Europe)......82

Figure 5.2 Diagram of Power Plugs for Three-Phase 9960 Disk Array Unit (USA) ........83

Figure 5.3 Diagram of Power Plugs for Three-Phase 9960 Disk Array Unit (Europe)......83

Figure 5.4 Internal Cable Diagram of a Single-Phase 9960 Subsystem ................86

Figure 5.5 Internal Cable Diagram of a Single-Phase 9910 Subsystem ................87

Figure 5.6 Power Plugs for Single-Phase 9960 Controller (USA).....................88

Figure 5.7 Power Plugs for Single-Phase 9910 Subsystem (USA).....................88

Figure 5.8 Power Plugs for a Single-Phase 9960 Controller (Europe).................89

Figure 5.9 Power Plugs for a Single-Phase 9910 Subsystem (Europe).................89

Figure 5.10 Power Plugs for Single-Phase 9960 Disk Array Unit (USA) .................90

Hitachi Lightning 9900™ User and Reference Guide xi

Figure 5.11

Figure 5.15 9960 DKC and DKU Physical Dimensions.............................. 93

Figure 5.16 9910 DKC and DKU Physical Dimensions.............................. 93

Figure 5.17 9960 Controller Frame Service Clearance and Cutouts (millimeters) ....... 97

Figure 5.18 9960 Controller Frame Service Clearance and Cutouts (inches) ........... 98

Figure 5.19 9960 Disk Array Unit Service Clearance and Cutout (millimeters).......... 99

Figure 5.20 9960 Disk Array Unit Service Clearance and Cutout (inches)............. 100

Figure 5.21 9960 Disk Subsystem Minimum Configuration (millimeters).............. 101

Figure 5.22 9960 Disk Subsystem Minimum Configuration (inches).................. 102

Figure 5.23 9910 Disk Subsystem All Configurations (millimeters).................. 103

Figure 5.24 9910 Disk Subsystem All Configurations (inches)...................... 104

Figure 5.25 9960 Disk Subsystem with Controller and 4 Disk Arrays................. 106

Figure 5.26 9960 Disk Subsystem with Maximum Configuration .................... 107

Figure 6.1 Typical 9900 SIM Showing Reference Code and SIM Type................ 116

List of Tables

Table 1.1 Program Products and Service Offerings .............................6-7

Table 2.1 CHIP and Channel Specifications ................................... 17

Table 2.2 ACP Specifications .............................................. 20

Table 2.3 Disk Drive Specifications ......................................... 22

Power Plugs for Single-Phase 9960 Disk Array Unit (Europe).............. 90

Table 3.1 Capacities of Standard LU Types ................................... 31

Table 3.2 Common System Option Modes .................................... 32

Table 3.3 System Option Modes for Mainframe Connectivity...................... 32

Table 3.4 System Option Modes for Open-System Connectivity.................... 33

Table 3.5 System Option Modes for ShadowImage - S/390® and ShadowImage........ 34

Table 3.6 System Option Modes for TrueCopy - S/390® Sync & Async............. 34-35

Table 3.7 System Option Modes for HXRC .................................... 36

Table 3.8 System Option Modes for Concurrent Copy (CC) ....................... 36

Table 3.9 Data Management Functions for Open-System Users.................... 38

Table 3.10 Data Management Functions for S/390® Users......................... 39

Table 4.1 SSID Requirements.............................................. 53

Table 4.2 Correspondence between Physical Paths and Channel Interface IDs (Cl 1) . . . 58
Table 4.3 Correspondence between Physical Paths and Channel Interface IDs (Cl 2) . . . 58

Table 4.4 HCD Definition for 64 LVIs ........................................ 59

Table 4.5 HCD Definition for 256 LVIs ....................................... 59

Table 4.6 ICKDSF Commands for 9900 Contrasted to RAMAC...................... 72

Table 4.7 9900 Open-System Platforms and Configuration Guides ................. 76

Table 5.1 9960 Three-Phase Features ....................................... 84

Table 5.2 Current Rating, Power Plug, Receptacle, and Connector for 3-Phase 9960. . . 84

Table 5.3 Input Voltage Specifications for Three-Phase Power.................... 85

Table 5.4 9900 Single-Phase Features ....................................... 91

Table 5.5 Current Rating, Power Plug, Receptacle, and Connector for 1-Phase 9900. . . 91

xii Contents

Table 5.6

Table 5.7 9900 Physical Specifications .......................................94

Table 5.8 9960 Frame and Component Weights ................................95

Table 5.9 9960 & 9910 Subsystem Weights ....................................95

Table 5.10 Floor Load Rating for 9910 Subsystem...............................105

Table 5.11 Floor Load Rating for 9960 Controller with 1 Disk Array.................105

Table 5.12 Floor Load Rating for 9960 Controller with 4 Disk Arrays ................107

Table 5.13 Floor Load Rating for 9960 Controller with Maximum Configuration........108

Table 5.14 Cable Requirements.............................................109

Table 5.15 ESCON® and FICON™ Port Information...............................110

Table 5.16 Fibre-Channel Port Information....................................110

Table 5.17 Temperature and Humidity Requirements ...........................111

Table 5.18 9910/9960 Component Power and Heat Output Specifications............112

Table 5.19 9900 Subsystem Power and Heat Output Specifications .................112

Table 5.20 Internal Air Flow ...............................................113

Table 5.21 Vibration and Shock Tolerances....................................114

Table 6.1 Troubleshooting................................................115

Table A.1 Unit Conversions for Standard (U.S.) and Metric Measures ...............119

Input Voltage Specifications for Single-Phase Power.....................92

Hitachi Lightning 9900™ User and Reference Guide xiii

xiv Contents

Chapter 1 Overview of the Lightning 9900™ Subsystem

1.1 Key Features of the Lightning 9900™ Subsystem

The Hitachi Lightning 9900™ subsystem provides high-speed response, continuous data
availability, scalable connectivity, and expandable capacity for both S/390

®

and open-

systems environments. The 9900 subsystem is designed for use in 7×24 data centers that
demand high-performance, non-stop operation. The 9900 subsystem is compatible with
industry-standard software and supports concurrent attachment to multiple host systems and
platforms. The 9900 subsystem employs and improves upon the key characteristics of
generations of successful Hitachi disk storage subsystems to achieve high performance and
reliability. The advanced components, functions, and features of the Lightning 9900™
subsystem represent an integrated approach to data retrieval and storage management.

The Lightning 9900™ subsystem provides many new benefits and advantages for the user.
The 9900 subsystem can operate with multihost applications and host clusters, and is
designed to handle very large databases as well as data warehousing and data mining
applications that store and retrieve terabytes of data. The Lightning 9900™ provides up to 32
host interface ports and can be configured for all-mainframe, all-open, or multiplatform
operations.

 Instant access to data around the clock:

– 100 percent data availability guarantee.

– No single point of failure.

– Highly resilient multi-path fibre architecture.

– Fully redundant, hot-swappable components.

– Global dynamic hot sparing.

– Duplexed write cache with battery backup.

– Hi-Track

®

“call-home” maintenance system.

– Non-disruptive microcode updates.

– RAID-1 and/or RAID-5 array groups within the same subsystem.

 Unmatched performance and capacity:

– Industry’s only internal switched fabric architecture.

– Multiple point-to-point data and control paths.

– Up to 6.4-GB/sec internal system bandwidth.

– Fully addressable 32-GB data cache; separate control cache.

– Extremely fast and intelligent cache algorithms.

– Non-disruptive expansion to over 88 TB raw capacity.

– Simultaneous transfers from up to 32 separate hosts.

– High-throughput 10K RPM fibre-channel, dual-active disk drives.

Hitachi Lightning 9900™ User and Reference Guide 1

 Extensive connectivity and resource sharing:

– Concurrent operation of UNIX

NetWare

®

, and S/390® host systems.

– Fibre-channel, Fiber Connection (FICON™), and Extended Serial Adapter™ (ESCON

server connections.

– Optimized for storage-area networks (SANs), fibre-channel switched, fibre-channel

arbitrated loop, and point-to-point configurations.

1.1.1 Continuous Data Availability

The Hitachi Lightning 9900™ is designed for nonstop operation and continuous access to all
user data. To achieve nonstop customer operation, the 9900 subsystem accommodates
online feature upgrades and online software and hardware maintenance. See section 1.2 for
further information on the reliability and availability features of the Lightning 9900™
subsystem.

1.1.2 Connectivity

®

-based, Windows NT®, Windows® 2000, Linux®,

®

)

The Hitachi Lightning 9900™ RAID subsystem supports concurrent attachment to S/390®
mainframe hosts and open-system (UNIX

®

-based and/or PC-server) platforms. The 9900
subsystem can be configured with FICON™ ports, Extended Serial Adapter™ (ExSA™) ports
(compatible with ESCON

®

protocol), and/or fibre-channel ports to support all-mainframe,

all-open, and multiplatform configurations.

When FICON™ channel interfaces are used, the 9900 subsystem can provide up to 16 logical
control unit (CU) images and 4096 logical device (LDEV) addresses. Each physical FICON™
channel interface supports up to 512 logical paths providing a maximum of 8192 logical paths
per subsystem. FICON™ connection provides transfer rates of up to 100 MB/sec (1Gbps).

When ExSA™ channel interfaces are used, the 9900 subsystem can provide up to 16 logical
control unit (CU) images and 4,096 logical device (LDEV) addresses. Each physical ExSA™
channel interface supports up to 256 logical paths providing a maximum of 8,192 logical
paths per subsystem. ExSA™ connection provides transfer rates of up to 17 MB/sec.

When fibre-channel interfaces are used, the 9900 subsystem can provide up to 32 ports for
attachment to UNIX

®

-based and/or PC-server platforms. The type of host platform
determines the number of logical units (LUs) that may be connected to each port. Fibre­channel connection provides data transfer rates of up to 200 MB/sec (2 Gbps). The 9900
subsystem supports fibre-channel arbitrated loop (FC-AL) and fabric fibre-channel topologies
as well as high-availability (HA) fibre-channel configurations using hubs and switches.

2 Chapter 1 Overview of the Lightning 9900™ Subsystem

1.1.3 S/390® Compatibility and Functionality

The 9900 subsystem supports 3990 and 2105 controller emulations and can be configured
with multiple concurrent logical volume image (LVI) formats, including 3390-1, -2, -3, -3R, -9
and 3380-E, -J, -K. In addition to full System-Managed Storage (SMS) compatibility, the 9900
subsystem also provides the following functionality in the S/390

 Sequential data striping,

 Cache fast write (CFW) and DASD fast write (DFW),

 Enhanced dynamic cache management,

 Multiple Allegiance support,

 Concurrent Copy (CC) support,

 Enhanced CCW support,

 Priority I/O queuing,

 Parallel Access Volume (PAV) support, and

 Transaction Processing Facility (TPF)/Multi-Path Locking Facility (MPLF) support.

1.1.4 Open-Systems Compatibility and Functionality

®

environment:

The Lightning 9900™ subsystem supports multiple concurrent attachment to a variety of host
operating systems (OS). The 9900 supports the following platforms at this time. The type of
host platform determines the number of logical units (LUs) that may be connected to each
port. Please contact Hitachi Data Systems for the latest information on platform and OS
version support. The 9900 is compatible with most fibre-channel host bus adapters (HBAs).

 IBM

 Sun™ Solaris™ OS

 HP-UX

 Compaq

 Sequent

 SGI™ IRIX

®

AIX® OS

®

OS

®

Tru64™ UNIX® OS

®

DYNIX/ptx® OS

®

OS

 Microsoft

 Microsoft

 Novell

 Red Hat

 Compaq

®

Windows NT® OS

®

Windows® 2000 OS

®

NetWare® OS

®

Linux® OS

®

OpenVMS® OS

The 9900 subsystem provides enhanced dynamic cache management and supports command
tag queuing and multi-initiator I/O. Command tag queuing (see section 4.5.1) enables hosts
to issue multiple disk commands to the fibre-channel adapter without having to serialize the
operations. The 9900 subsystem operates with industry-standard middleware products
providing application/host failover capability, I/O path failover support, and logical volume
management. The 9900 subsystem also supports the industry-standard simple network
management protocol (SNMP) for remote management from the open-system host.

The 9900 subsystem can be configured with multiple concurrent logical unit (LU) formats
(e.g., OPEN-3, -8, -9, -K, -E, -L, -M). The user can also configure custom-size volumes using
the Virtual LVI/LUN and LU Size Expansion (LUSE) features of the 9900 subsystem, which are
described in the next section.

Hitachi Lightning 9900™ User and Reference Guide 3

1.1.5 Hitachi Freedom NAS™ and Hitachi Freedom SAN™

Hitachi Freedom Data Networks™ (FDN) provide an open architecture that offers
organizations freedom of choice in deploying data access, protection, and sharing
capabilities across the enterprise. Using multiple technologies and solutions such as storage­area networks (SANs) and network-attached storage (NAS), FDN builds, leverages, and
augments storage infrastructures, providing access to any data from any computer, anytime
and anywhere.

Hitachi Freedom NAS™ and Hitachi Freedom SAN™ solutions are the core offerings behind the
FDN approach. They complement the Hitachi Freedom Storage™ subsystems by allowing
more flexibility than ever in heterogeneous environments. While SAN architectures respond
to high bandwidth needs, NAS addresses the need for rapid file access, especially critical for
e-business applications. Hitachi Data Systems offers the best of both.

FDN encompasses storage, switches and hubs, servers/clients, management software,
protocols, services, and networks developed by Hitachi, our alliance partners, and third
party providers. FDN facilitates consolidation of server and storage resources, data sharing
among heterogeneous hosts, centralized resource and data management, superior data
security, and increased connectivity.

Hitachi Freedom SAN™. Hitachi Data Systems’ SAN solutions give you the freedom to locate
storage wherever needed and protect your investment in currently installed components.
Made possible by the advent and proliferation of high-speed fibre-channel technology, SANs
break the traditional server/storage bond and enable total connectivity. As a result, you can
add, remove, or reassign any resource without interfering with ongoing business operations.

The Lightning 9900™ subsystem features unparalleled reliability, a SAN-ready architecture,
and support for S/390

®

, UNIX®, and Windows NT® platforms. Hitachi adds software and
services to SAN components to provide functionality such as LAN-free backup, remote copy,
and multiplatform data exchange from our Freedom Storage™ software suites.

4 Chapter 1 Overview of the Lightning 9900™ Subsystem

Hitachi Freedom NAS™. Freedom NAS answers the need for speed with faster file access.
Numerous clients can instantly share data with information available on your NAS file server.
Freedom NAS is an excellent solution for file/web serving, document/record imaging,
streaming media, video design, telco call centers, and manufacturing.

Hitachi Freedom Storage™ subsystems are combined with Network Storage Solutions’ NAS file
servers to provide Freedom NAS solutions. The modular architecture of Hitachi Freedom
Storage™ subsystems provides quick and easy storage expansion. For further information,
please refer to the Hitachi Freedom NAS™ NSS Configuration Guide, MK-91RD053.

Freedom NAS provides the following benefits for the user:

 Accelerates response times

 Supports rapid deployment of new

applications

 Satisfies increasing customer demand

 Enables expanding operations

 Leverages existing storage infrastructure

 Improves service levels

 Reduces I/O bottlenecks

 Minimizes overhead through

consolidation and reduced
complexity

 Increases availability and

reliability

 Eliminates storage islands

 Installs quickly and easily

Hitachi Lightning 9900™ User and Reference Guide 5

1.1.6 Program Products and Service Offerings

The Lightning 9900™ subsystem provides many advanced features and functions that increase
data accessibility, enable continuous user data access, and deliver enterprise-wide coverage
of on-line data copy/relocation, data access/protection, and storage resource management.
Hitachi Data Systems’ software solutions provide a full complement of industry-leading copy,
availability, resource management, and exchange software to support business continuity,
database backup/restore, application testing, and data mining.

Table 1.1 Program Products and Service Offerings (continues on the next page)

Function Description See Section:

Data Replication:

Hitachi TrueCopy (TC)
Hitachi TrueCopy – S/390

Hitachi ShadowImage (SI)
Hitachi ShadowImage – S/390

Command Control Interface (CCI) Enables open-system users to perform TrueCopy and ShadowImage operations

Extended Copy Manager (ECM) Provides server-free backup solutions between the 9900 and backup devices

Hitachi Extended Remote Copy
(HXRC)

Hitachi NanoCopy™ Enables S/390® users to make Point-in-Time (PiT) copies of production data,

Data migration
(service offering only)

®

(TC390)

®

(SI390)

Enables the user to perform remote copy operations between 9900 subsystems
(and 7700E and 7700) in different locations. Hitachi TrueCopy provides
synchronous and asynchronous copy modes for both S/390
data. (The 7700 subsystem supports only synchronous remote copy operations.)

Allows the user to create internal copies of volumes for a wide variety of
purposes including application testing and offline backup. Can be used in
conjunction with TrueCopy to maintain multiple copies of critical data at both the
primary and secondary sites.

by issuing commands from the host to the 9900 subsystem. The CCI software
supports scripting and provides failover and mutual hot standby functionality in
cooperation with host failover products.

(e.g., tape, disk) in SAN environments. Supports the SCSI Extended Copy
command issued from the host server to the 9900 subsystem.

Provides compatibility with the IBM® Extended Remote Copy (XRC) S/390® host
software function, which performs server-based asynchronous remote copy
operations for mainframe LVIs.

without quiescing the application or causing any disruption to end-user
operations, for such uses as application testing, business intelligence, and
disaster recovery for business continuance.

Enables the rapid transfer of data from other disk subsystems onto the 9900
subsystem. Data migration operations can be performed while applications are
online using the data which is being transferred.

®

and open-system

3.7.1

3.7.2

3.7.3

3.7.4

3.7.5

3.7.6

3.7.7

3.7.8

3.7.9

Backup/Restore and Data Sharing:

Hitachi RapidXchange (HRX) Enables users to transfer data between S/390® and open-system platforms

Hitachi Multiplatform Backup/Restore
(HMBR)

HARBOR® File-Level Backup/Restore Enables users to perform mainframe-based file-level backup/restore operations

HARBOR® File Transfer Enables users to transfer large data files at ultra-high channel speeds in either

using the ExSA™ and/or FICON™ channels, which provides high-speed data
transfer without requiring network communication links or tape.

Allows users to perform mainframe-based volume-level backup and restore
operations on the open-system data stored on the multiplatform 9900
subsystem.

on the open-system data stored on the multiplatform 9900 subsystem.

direction between open systems and mainframe servers.

6 Chapter 1 Overview of the Lightning 9900™ Subsystem

3.7.10

3.7.11

3.7.12

3.7.13

Table 1.1 Program Products and Service Offerings (continued)

Function Description See Section:

Resource Management:

HiCommand™ Enables users to manage the 9900 subsystem and perform functions (e.g., LUN

Manager, SANtinel) from virtually any location via the HiCommand™ Web
Client, command line interface (CLI), and/or third-party application.

LUN Manager Enables users to configure the 9900 fibre-channel ports for operational

environments (e.g., arbitrated-loop (FC-AL) and fabric topologies, host failover
support).

LU Size Expansion (LUSE) Enables open-system users to create expanded LUs which can be up to 36

times larger than standard fixed-size LUs.

Virtual LVI (VLVI)
Virtual LUN (VLUN)

Enables users to configure custom-size LVIs and LUs which are smaller than
standard-size devices.

FlashAccess (Flsh) Enables users to store specific high-usage data directly in cache memory to

provide virtually immediate data availability.

Cache Manager Enables users to perform FlashAccess operations from the S/390® host system.

FlashAccess allows you to place specific data in cache memory to enable
virtually immediate access to this data

Hitachi SANtinel
Hitachi SANtinel – S/390

®

Allows users to restrict host access to data on the Lightning 9900™ subsystem.
Open-system users can restrict host access to LUs based on the host’s World
Wide Name (WWN). S/390

®

mainframe users can restrict host access to LVIs

based on node IDs and logical partition (LPAR) numbers.

Prioritized Port Control (PPC) Allows open-system users to designate prioritized ports (e.g., for production

servers) and non-prioritized ports (e.g., for development servers) and set
thresholds and upper limits for the I/O activity of these ports.

Hitachi Parallel Access Volume
(HPAV)

Enables the S/390® host system to issue multiple I/O requests in parallel to
single LDEVs in the Lightning 9900™ subsystem. HPAV provides compatibility
with the IBM® Workload Manager (WLM) host software function and supports
both static and dynamic PAV functionality.

3.7.14

3.7.15

3.7.16

3.7.17

3.7.18

3.7.19

3.7.20

3.7.21

3.7.22

3.7.23

Dynamic Link Manager™ Provides automatic load balancing, path failover, and recovery capabilities in the

3.7.24

event of a path failure.

LDEV Guard Enables the assigning of access permissions (Read/Write, Read-Only, and

MK-92RD072
Protect) to logical volumes in a disk subsystem. 3390-3A, 3390-3B and 3390-3C
volumes can be used by both mainframe hosts and open-system hosts.

Note: Please check with your Hitachi Data Systems representative for the latest
feature availability.

Storage Utilities:

Hitachi CruiseControl Monitors subsystem and volume activity and performs automatic relocation of

3.7.26

volumes to optimize performance.

Hitachi Graph-Track™ (GT) Provides detailed information on the I/O activity and hardware performance of

3.7.27
the 9900 subsystem. Hitachi Graph-Track™ displays real-time and historical
data in graphical format, including I/O statistics, cache statistics, and front-end
and back-end microprocessor usage.

Hitachi Lightning 9900™ User and Reference Guide 7

1.1.7 Subsystem Scalability

The architecture of the 9900 subsystem accommodates scalability to meet a wide range of
capacity and performance requirements. The 9960 storage capacity can be increased from a
minimum of 54 GB to a maximum of 88 TB of user data. The 9960 nonvolatile cache can be
configured from 1 GB to 32 GB. All disk drive and cache upgrades can be performed without
interrupting user access to data.

The 9900 subsystem can be configured with the desired number and type of front-end client­host interface processors (CHIPs). The CHIPs are installed in pairs, and each CHIP pair offers
up to eight host connections. The 9960 can be configured with four CHIP pairs to provide up
to 32 paths to attached host processors. The 9910 supports up to three CHIP pairs and 24
paths.

The ACPs are the back-end processors which transfer data between the disk drives and
cache. Each ACP pair is equipped with eight device paths. The 9960 subsystem can be
configured with up to four pairs of array control processors (ACPs), providing up to thirty­two concurrent data transfers to and from the disk drives. The 9910 is configured with one
ACP pair.

8 Chapter 1 Overview of the Lightning 9900™ Subsystem

1.2 Reliability, Availability, and Serviceability

The Lightning 9900™ subsystem is not expected to fail in any way that would interrupt user
access to data. The 9900 can sustain multiple component failures and still continue to
provide full access to all stored user data. Note: While access to user data is never
compromised, the failure of a key component can degrade performance.

The reliability, availability, and serviceability features of the 9900 subsystem include:

 Full fault-tolerance. The 9900 subsystem provides full fault-tolerance capability for all

critical components. The disk drives are protected against error and failure by enhanced
RAID technologies and dynamic scrubbing and sparing. The 9900 uses component and
function redundancy to provide full fault-tolerance for all other subsystem components
(microprocessors, control storage, power supplies, etc.). The 9900 has no active single
point of component failure and is designed to provide continuous access to all user data.

 Separate power supply systems. Each storage cluster is powered by a separate set of

power supplies. Each set can provide power for the entire subsystem in the unlikely
event of power supply failure. The power supplies of each set can be connected across
power boundaries, so that each set can continue to provide power if a power outage
occurs. The 9900 can sustain the loss of multiple power supplies and still continue
operation.

 Dynamic scrubbing and sparing for disk drives. The 9900 uses special diagnostic

techniques and dynamic scrubbing to detect and correct disk errors. Dynamic sparing is
invoked automatically if needed. The 9960 can be configured with up to sixteen spare
disk drives, and any spare disk can back up any other disk of the same capacity, even if
the failed disk and spare disk are in different array domains (attached to different ACP
pairs).

 Dynamic duplex cache. The 9900 cache is divided into two equal segments on separate

power boundaries. The 9900 places all write data in both cache segments with one
internal write operation, so the data is always duplicated (duplexed) across power
boundaries. If one copy of write data is defective or lost, the other copy is immediately
destaged to disk. This duplex design ensures full data integrity in the event of a cache or
power failure.

 Remote copy features. The Hitachi TrueCopy and Hitachi Extended Remote Copy

(HXRC) data movement features enable the user to set up and maintain duplicate copies
of S/390

®

and open-system data over extended distances. In the event of a system
failure or site disaster, the secondary copy of data can be invoked rapidly, allowing
applications to be recovered with guaranteed data integrity.

Hitachi Lightning 9900™ User and Reference Guide 9

 Hi-Track

®

. The Hi-Track® maintenance support tool monitors the operation of the 9900

subsystem at all times, collects hardware status and error data, and transmits this data
via modem to the Hitachi Data Systems Support Center. The Hitachi Data Systems
Support Center analyzes the data and implements corrective action when necessary. In
the unlikely event of a component failure, Hi-Track

®

calls the Hitachi Data Systems
Support Center immediately to report the failure without requiring any action on the
part of the user. Hi-Track

®

enables most problems to be identified and fixed prior to

actual failure, and the advanced redundancy features enable the subsystem to remain
operational even if one or more components fail. Note: Hi-Track
to any user data stored on the 9900 subsystem. The Hi-Track

®

does not have access

®

tool requires a dedicated

RJ-11 analog phone line.

 Nondisruptive service and upgrades. All hardware upgrades can be performed

nondisruptively during normal subsystem operation. All hardware subassemblies can be
removed, serviced, repaired, and/or replaced nondisruptively during normal subsystem
operation. All microcode upgrades can be performed during normal subsystem
operations using the SVP or the alternate path facilities of the host.

 Error Reporting. The Lightning 9900™ subsystem reports service information messages

(SIMs) to notify users of errors and service requirements. SIMs can also report normal
operational changes, such as remote copy pair status change. The SIMs are logged on the
9900 service processor (SVP) and on the Remote Console PC, reported directly to the
mainframe and open-system hosts, and reported to Hitachi Data Systems via Hi-Track

®

.

10 Chapter 1 Overview of the Lightning 9900™ Subsystem

Chapter 2 Subsystem Architecture and Components

2.1 Overview

Figure 2.1 shows the Hierarchical Star Network (HiStar or HSN) architecture of the Lightning
9900™ RAID subsystem. The “front end” of the 9900 subsystem includes the hardware and
software that transfers the host data to and from cache memory, and the “back end”
includes the hardware and software that transfers data between cache memory and the disk
drives.

control cache

Data Cache

Cache/Data Side

Cache Switch

Processor Side

CHT

DTA MPA

CHT

DTAMPA

Data Cache Data Cache

Cache/Data Side

Cache Switch

Processor Side

DTA MPA

ACP

Cache/Data Side

Cache Switch

Processor Side

DTAMPA

ACP

control cache

Data Cache

Cache/Data Si de

Cache Switch

Processor Side

Figure 2.1 Lightning 9900™ HiStar Network (HSN) Architecture

Hitachi Lightning 9900™ User and Reference Guide 11

Front End: The 9900 front end is entirely resident in the 9900 controller frame and includes
the client-host interface processors (CHIPs) that reside on the channel adapter (CHA or CHT)
boards. The CHIPs control the transfer of data to and from the host processors via the fibre­channel, ExSA™, and/or FICON™ channel interfaces and to and from cache memory via
independent high-speed paths through the cache switches (CSWs).

 Each channel adapter board (CHA or CHT) can contain two or four CHIPs. The 9960

subsystem supports up to eight CHAs for a maximum of 32 host interfaces, and the 9910
subsystem supports up to six CHAs to provide a maximum of 24 host interfaces.

 The 9960 controller contains four cache switch (CSW) cards, and the 9910 controller

contains two CSW cards.

 Cache memory in the 9960 resides on two or four cards depending on features, and each

cache card is backed up by a separate battery. The 9910 supports two cache cards.

 Shared memory resides on the first two cache cards and is provided with its own power

sources and backup batteries. Shared memory also has independent address and data
paths from the channel adapter and disk adapter boards.

Back End: The 9900 back end is controlled by the array control processors (ACPs) that reside
on the disk adapter boards in the 9900 controller frame. The ACPs control the transfer of
data to and from the disk arrays via high-speed fibre (100 MB/sec or 1 Gbps) and then to and
from cache memory via independent high-speed paths through the CSWs.

 The disk adapter board (DKA) contains four ACPs. The 9960 subsystem supports up to

eight DKAs for a maximum of 32 ACPs. The 9910 subsystem supports two DKAs for a
maximum of eight ACPs.

The 9960 subsystem (see Figure 2.2) includes the following major components:

 One controller frame containing the control and operational components of the

subsystem.

 Up to six disk array frames containing the storage components (disk drive arrays) of the

subsystem.

 The service processor (SVP) (see section 2.5). The 9900 SVP is located in the controller

frame and can only be used by authorized Hitachi Data Systems personnel.

 The Remote Console PC (see section 2.6). The 9900 Remote Console PC can be attached

to multiple 9960 and/or 9910 subsystems via the 9900-internal local-area network (LAN).

The 9910 subsystem (see Figure 2.3) includes the following major components:

 One frame containing the controller and disk components of the subsystem.

 The service processor (SVP) (see section 2.5). The 9900 SVP is located in the controller

frame and can only be used by authorized Hitachi Data Systems personnel.

 The Remote Console PC (see section 2.6). The 9900 Remote Console PC can be attached

to multiple 9960 and/or 9910 subsystems.

12 Chapter 2 Subsystem Architecture and Components

Minimum configuration of 9960 subsystem

Disk Array Unit Disk Array Unit Disk Array Unit 9900 Controller Disk Array Unit Disk Array Unit Disk Arr ay Unit

Figure 2.2 9960 Subsystem Frames

Figure 2.3 9910 Subsystem Frame

Hitachi Lightning 9900™ User and Reference Guide 13

2.2 Components of the Controller Frame

The 9900 controller frame contains the control and operational components of the
subsystem. For the 9910 subsystem, the controller frame also contains the disk array
components. The 9900 controller is fully redundant and has no active single point of failure.
All controller frame components can be repaired or replaced without interrupting access to
user data. The key features and components of the controller frame are:

 Storage clusters (see section 2.2.1),

 Nonvolatile duplex shared memory (see section 2.2.2),

 Nonvolatile duplex cache memory (see section 2.2.3),

 Multiple data and control paths (see section 2.2.4),

 Redundant power supplies (see section 2.2.5),

 CHIPs and channels (FICON™, ExSA™, and/or fibre-channel) (see section 2.2.6),

 ACPs (see section 2.2.8).

2.2.1 Storage Clusters

Each controller frame consists of two redundant controller halves called storage clusters.
Each storage cluster contains all physical and logical elements (e.g., power supplies, CHAs,
CHIPs, ACPs, cache, control storage) needed to sustain processing within the subsystem.
Both storage clusters should be connected to each host using an alternate path scheme, so
that if one storage cluster fails, the other storage cluster can continue processing for the
entire subsystem.

Each pair of channel adapters is split between clusters to provide full backup for both front­end and back-end microprocessors. Each storage cluster also contains a separate, duplicate
copy of cache and shared memory contents. In addition to the high-level redundancy that
this type of storage clustering provides, many of the individual components within each
storage cluster contain redundant circuits, paths, and/or processors to allow the storage
cluster to remain operational even with multiple component failures. Each storage cluster is
powered by its own set of power supplies, which can provide power for the entire subsystem
in the unlikely event of power supply failure. Because of this redundancy, the Lightning
9900™ subsystem can sustain the loss of multiple power supplies and still continue operation.

Note: The redundancy and backup features of the Lightning 9900™ subsystem eliminate all
active single points of failure, no matter how unlikely, to provide an additional level of
reliability and data availability.

14 Chapter 2 Subsystem Architecture and Components

2.2.2 Nonvolatile Shared Memory

The nonvolatile shared memory contains the cache directory and configuration information
for the 9900 subsystem. The path group arrays (e.g., for dynamic path selection) also reside
in the shared memory. The shared memory is duplexed, and each side of the duplex resides
on the first two cache cards, which are in clusters 1 and 2. Even though the shared memory
resides on the cache cards, the shared memory has separate power supplies and separate
battery backup. The basic size of the shared memory is 512 MB, and the maximum size is 1.5
GB (for 9960). The size of the shared memory storage is determined by the total cache size
and the number of logical devices (LDEVs). Any required increase beyond the base size is
automatically shipped and configured during the upgrade process. The shared memory is
protected by battery backup.

2.2.3 Nonvolatile Duplex Cache

The 9960 subsystem can be configured with up to 32 GB of cache, and the 9910 can be
configured with up to 16 GB of cache. All cache memory in the 9900 is nonvolatile, and each
cache card is protected by its own 48-hour battery backup. The cache in the 9900 is divided
into two equal areas (called cache A and cache B) on separate cards. Cache A is in cluster 1,
and cache B is in cluster 2. The 9900 places all read and write data in cache. Write data is
normally written to both cache A and B with one CHIP write operation, so that the data is
always duplicated (duplexed) across logic and power boundaries. If one copy of write data is
defective or lost, the other copy is immediately destaged to disk. This “duplex cache”
design ensures full data integrity in the unlikely event of a cache memory or power-related
failure.

Note: Mainframe hosts can specify special attributes (e.g., cache fast write (CFW)
command) to write data (typically a sort command) without write duplexing. This data is not
duplexed and is usually given a discard command at the end of the sort, so that the data will
not be destaged to the disk drives. See section 4.3.3 for further information on S/390
operations.

®

cache

Hitachi Lightning 9900™ User and Reference Guide 15

2.2.4 Multiple Data and Control Paths

The 9900 subsystem uses a state-of-the-art architecture called the Hierarchical Star (HiStar)
Network (HSN) which utilizes multiple point-to-point data and command paths in order to
provide redundancy and improve performance. Each data and command path is independent.
The individual paths between the channel or disk adapters and cache are steered by high­speed cache switch cards. The 9900 does not have any common buses, thus eliminating the
performance degradation and contention that can occur in a bus architecture. All data
stored on the 9900 subsystem is moved into and out of cache via the redundant high-speed
paths.

2.2.5 Redundant Power Supplies

Each storage cluster is powered by its own set of redundant power supplies, and each power
supply is able to provide power for the entire subsystem, if necessary. Because of this
redundancy, the 9900 subsystem can sustain the loss of multiple power supplies and still
continue operation. To make use of this capability, the 9900 should be connected either to
dual power sources or to different power panels, so if there is a failure on one of the power
sources, the 9900 can continue full operations using power from the alternate source.

2.2.6 Client-Host Interface Processors (CHIPs) and Channels

The CHIPs contain the front-end microprocessors which process the channel commands from
the host(s) and manage host access to cache. In the S/390
CKD-to-FBA and FBA-to-CKD conversion for the data in cache. The CHIPs are available in
pairs. Depending on the configuration, each CHIP in a pair contains either two or four
microprocessors and four buffers which allow data to be transferred between the CHIP and
cache. Each CHIP pair is composed of the same type of channel interface (FICON™, ExSA™, or
fibre-channel). Each ExSA™ or fibre-channel CHIP pair supports either four or eight
simultaneous data transfers to and from cache and four or eight physical connections to the
host. Each FICON™ CHIP pair supports four physical connections to the host. The 9900 can be
configured with multiple CHIP pairs to support various interface configurations. Table 2.1
lists the CHIP specifications and configurations and the number of channel connections for
each configuration.

Note: The Hitachi CruiseControl and Graph-Track products (see section 3.7) allow users to
collect and view usage statistics for the CHIPs in the 9900 subsystem.

®

environment, the CHIPs perform

16 Chapter 2 Subsystem Architecture and Components