HP C9578-90030 User Manual

hp surestore

installation and

interface manager

service guide

Part Number: C9578-90030

Edition 1

December 2001

Typographical conventions and

In this manual

terms

Bold: Menu choices and screens on the

library.

[Bold]: Soft keys to press on the library.

Computer:

Emphasis: Draws attention to items within

This table format indicates the menus you need to enter on the library front panel:

Edit -> Create -> SCSI-II Library

Note Notes explain significant concepts or

Caution Cautions call attention to an operating

WARNING Warnings call attention to a procedure

Host and SCSI commands.

text.

operating instructions.

procedure or practice that could damage the product if not correctly performed. Do not proceed until you understand and meet these required conditions.

or practice that could result in personal injury if not correctly performed. Do not proceed until you fully understand and meet the required conditions.

Chapter 1 Introduction: Describes the

operation of the Interface Manager, as well as components and supported products.

Chapter 2 Overview: Provides an overview

of the configuration options.

Chapter 3 Installation: Describes how to

install the interface manager, as well as power distribution, connections and configurations.

Chapter 4 Management Operations:

Describes the management operations, system utilities and statistics, diagnostics and trace history.

Chapter 5 SAN Environments: Provides an

overview of Storage Area Networks.

Chapter 6 Removing and Replacing Parts:

Describes how to remove and replace field replaceable units.

Chapter 7 Troubleshooting: Describes the

troubleshooting process, as well as problem-solution scenarios.

Appendix A DB-9 Serial and RJ-45 Ethernet

Pin Assignment

Appendix B Fibre Channel Interface and

Commands Appendix C SCSI Interface and Commands Appendix D Customer Support

2 Typographical conventions and terms hp surestore interface manager

Notice

This document contains information that is protected by copyright. All rights are reserved. No part of this document may be photocopied, reproduced, or translated into another language. The information contained in this document is subject to change without notice.

Warranty

Note See Appendix D for more

information about service and support.

HP Product: HP Surestore Interface Manager Duration of limited warranty: One Year

1. HP warrants HP hardware, accessories, and

supplies against defects in materials and workmanship for the period specified above. If Hewlett-Packard receives notice of such defects during the warranty period, Hewlett-Packard will, at its option, either repair or replace products which prove to be defective. Replacement products may be either new or like-new.

2. HP warrants that HP software will not fail to

execute its programming instructions, for the period specified above, due to defects in material and workmanship when properly installed and used. If HP receives notice of such defects during the warranty period, HP will replace software media that does not execute its programming instructions due to such defects.

3. HP does not warrant that the operation of HP

products will be uninterrupted or error free. If HP is unable, within a reasonable time, to repair or replace any product to a condition as warranted, customer will be entitled to a refund of the purchase price upon prompt return of the product.

4. HP products may contain remanufactured parts

equivalent to new in performance or may have been subject to incidental use.

5. The warranty period begins on the date of

delivery or on the date of installation if installed by HP. If customer schedules or delays HP installation more than 30 days after delivery, warranty begins on the 31st day from delivery.

6. Warranty does not apply to defects resulting from

(a) improper or inadequate maintenance or calibration, (b) software, interfacing, parts or supplies not supplied by HP, (c) unauthorized modification or misuse, (d) operation outside of the published environmental specifications for the products, or (e) improper site preparation or maintenance.

7. TO THE EXTENT ALLOWED BY LOCAL LAW, THE

ABOVE WARRANTIES ARE EXCLUSIVE AND NO OTHER WARRANTY OR CONDITION, WHETHER WRITTEN OR ORAL, IS EXPRESSED OR IMPLIED AND HP SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OR CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, AND FITNESS FOR A PARTICULAR PURPOSE.

8. HP will be liable for damage to tangible property

per incident up to the greater of $300,000 or the actual amount paid for the product that is the subject of the claim, and for damages for bodily injury or death, to the extent that all such damages are determined by a court of competent jurisdiction to have been directly caused by a defective HP product.

9. TO THE EXTENT ALLOWED BY LOCAL LAW, THE

REMEDIES IN THIS WARRANTY STATEMENT ARE THE CUSTOMER’S SOLE AND EXCLUSIVE REMEDIES. EXCEPT AS INDICATED ABOVE, IN NO EVENT WILL HP OR ITS SUPPLIERS BE LIABLE FOR LOSS OF DATA OR FOR DIRECT, SPECIAL, INCIDENTAL, CONSEQUENTIAL (INCLUDING LOST PROFIT OR DATA), OR OTHER DAMAGE, WHETHER BASED IN CONTRACT, TORT, OR OTHERWISE.

hp surestore interface manager Notice 3

Reference Standards

■ Fibre Channel Physical and Signaling Interface

(FC-PH), ANSI X3T9.3/Project 755D/Rev. 4.3, Contact: Global Engineering, 1-800-854-7179.

■ Fibre Channel Protocol for SCSI (FCP) Rev. 12

■ Fibre Channel Private Loop Direct Attach (FC-

PLDA).

■ Fibre Channel Arbitrated Loop (FC-AL), ANSI

X3T11/Project 960D/ Rev. 4.54, Contact: Global Engineering, 1-800-854-7179.

■ Gigabit Interface Converter (GBIC), Small for

Factor, SFF-8053, Rev. 5.X.

■ Common FC-PH Feature Sets Profiles, Fibre

Channel Systems Initiative, FCSI-101-Rev. 3.1.

■ SCSI Profile, Fibre Channel System Initiatives,

FCSI-201-Rev. 2.2.

■ FCSI IP Profile, Fibre Channel System Initiative,

FCSI-202-Rev. 2.1.

■ ANSI Document T10/99-143 r1 www.t10.org.

4 Reference Standards hp surestore interface manager

Typographical conventions and terms 2 In this manual 2 Notice 3 Warranty 3 Reference Standards 4

Chapter 1 Introduction 11

Chapter Overview 11 How the Interface Manager (IM) Works 12 Processing SCSI Information 14 Interface Manager (IM) Features 15

Fibre Channel Features 15 SCSI Bus Features 15 Configuration Features 15 Management Features 16

Interface Manager (IM) Components 17

Supplied Components for the Interface Manager 17

Specifications 19

Physical Specifications of the Interface Manager (IM) 19 Environmental Specifications 19

Supported Products 20

Optical Fibre Channel Cables 22

contents

Chapter 2 Interface Manager Overview 23

Chapter Overview 23 Overview of the Interface Manager (IM) Configuration 24 Choosing the Right Configuration 25

Fibre Channel Port Mode 28 Fibre Channel Arbitrated Loop Addressing 29

Hard Addressing 29

Soft Addressing 29 Host Device Configuration 30 SCSI Addressing 30 Buffered Tape Writes 30 Address Mapping 31

Auto-Indexed Mapping 32

Fixed-Indexed Mapping 32 Configuration Methods 33

Serial 33

Ethernet 33

Telnet 33 Web Based Administrator 34

Chapter 3 Installation 35

Chapter Overview 35 Supported Products 36 Overview of Installation: CE (Customer Engineer) Installation 37

Location 37 Interface Manager Components 38

Installing the Interface Manager 39

Attaching the Mounting Rails 41

Attaching the Flush Mount Brackets 46

Installing the Power Distribution Unit (PDU) 48 Installing Fibre Channel (FC) Interface Cards 50

Fibre Channel Interface Card Installation 51

Interface Manager SCSI Cable Connections 52

Installing SCSI Cables 52 Connecting the Library Controller 57

Setting Up Serial Port Communications 58 Powering on the Interface Manager 60

Powering on the System 60 Power-On Sequence for the Interface Manager 60 Power-Up Messages 62

Initial Configuration of the Remote Management Card (RMC) 64

Network Access 65 Configuring the Interface Manager 66

Chapter 4 Management Operations 69

Chapter Overview 69 Management Interfaces 70

Serial 70 Ethernet 70 Telnet 70 Web Based Administrator 71 FTP 71

Configuration Using the Telnet Interface 72

Overview 72 Accessing Telnet 72 Changing the Administration Password Using Telnet 74 Changing the Clock Setting Using Telnet 74 Changing the Ethernet Configuration Using Telnet 76 Changing the Fibre Channel Address Modes Using Telnet 76

Hard Addressing 77 Soft Addressing 78

Using Your Own Settings 78 Placing a Fibre Channel Interface Card Off-Line Using Telnet 79 Placing a Fibre Channel Interface Card On-Line Using Telnet 81 Installing a New Fibre Channel Interface Card Using Telnet 83 Changing a Fibre Channel Interface Card Configuration Using Telnet 85 Choosing Which Card to be Configured 85 Factory Defaults for the Fibre Channel Interface Card 86

Configuration Using the Web Based Administrator 87

Overview 87 Accessing the Web Based Administrator 89 Making Changes via the Web Interface 90 Changing the Clock Setting Using the Web Administrator 90

Setting Date and Time 90

Time Shown is NOT Correct 91

Setting a Time That is Different From the Time Shown 92 Changing the Ethernet Configuration Using the Web Administrator 92

Using DHCP 93

Not Using DHCP 94 Changing the FC Address Modes Using the Web Administrator 94

Hard Address Settings 96

Soft Address Settings 96

Selecting Your Own Settings 97 Placing a FC Interface Card Off-Line Using the Web Administrator 98 Placing a FC Interface Card On-Line Using the Web Administrator 101 Installing a New Interface Card Using the Web Administrator 104

Download a New Revision of the Firmware 106

Using the Web Interface 106

FTP Interface (All Cards)- Customer Engineer (CE) Only 108

Upgrade Firmware Using FTP 108 FTP Interface (Single Card) 109

Upgrade Firmware Using FTP 109

Chapter 5 SAN Environments 111

Chapter Overview 111 Installation and Configuration 112 Omniback Configuration 115 HP-UX Configuration 119

Stopping the dm_stape process 122 Preventing dm_stape from polling 125

Windows Configuration 126

Windows 2000 Removable Storage Manager 126

Solaris Configuration 128 Switch Configuration 129

HP/Brocade Switch and Interface Manager Configuration 129 FC-64 Director (McData) Switch 130

Chapter 6 Troubleshooting 131

Chapter Overview 131 Troubleshooting 132 Operation Indicators 133

Basic Verification 137

LED Indicators 137

Verify SCSI Bus Configuration 137

Verify Fibre Channel (FC) Connection 138

Verify SCSI Devices in Windows NT 138

Verify Device Recognition in HP-UX 138

Verify Configuration 140

Verify Devices 140

Verify Host Configuration 140 Verify HBA Device Driver Information 140 Serial Port Problems 140 Customer Support 141

Problem - Solution 142

Problem: Drives Not Detected after Power Failure 142

Option 1 - Not Using Telnet or the Web Interface 142 Option 2 - Using Telnet 142

Option 3 - Using the Web Interface 142 Problem: Cannot Turn on the Interface Manager 143 Problem: Cannot Confirm the Library Connection (Windows NT) 143 Problem: Cannot Confirm Connection Through a Fibre Channel Switch 145 Problem: Cannot Confirm the Library Connection (HP-UX) 145

Chapter 7 Removing and Replacing Parts 149

Chapter Overview 149 Field Replaceable Units (FRUs) 150 Replacing the Interface Manager Chassis 152 Removing and Replacing the Remote Management or Controller Card 153

Removing Cards: Remote Management (RMC), and Controller 154 Replacing a Card: Remote Management (RMC), and Controller 154

Removing and Replacing a Fibre Channel Interface Card 156

Removing a Fibre Channel Interface Card 156 Replacing a Fibre Channel Card 157

Removing and Replacing the Redundant Power Supply 158

Removing Individual Power Supply Units 158 Replacing the Redundant Power Supply Module 159 Removing a Fan 161 Replacing a Fan 162

Upgrading Firmware 163

Checking the Firmware Revision 163 Using a Host Diagnostic Utility 164

Using HP Library & Tape Tools (Windows only) 164

Using Support Tools Manager (HP-UX and MPE/iX only) 164

Appendix A DB-9 Serial and RJ-45 Ethernet Pin Assignment 165

Serial and Ethernet Assignment 165

Appendix B Fibre Channel Interface and Commands 167

Download Commands 167

Upgrade Firmware 167 Report LUNs Command 169 PRLI Data 171

Appendix C SCSI Interface and Commands 173

SCSI Inquiry Data 173

Appendix D Customer Support 175

Registering Your Product 175

Backup Software Support 175

Hewlett-Packard Customer Support 176

Information Needed for Support 176

Introduction

Chapter Overview

This chapter contains information on the following:

■ How the Interface Manager (IM) Works on page 12

■ Processing SCSI Information on page 14

■ Interface Manager (IM) Features on page 15

■ Interface Manager (IM) Components on page 17

■ Specifications on page 19

■ Supported Products on page 20

Introduction 11

How the Interface Manager (IM) Works

The IM provides connectivity between a Fibre Channel (FC) switched fabric (FC-SW) or Fibre Channel arbitrated loop (FC-AL) and up to 20 Ultra-2 SCSI buses.

The IM contains slots for up to eleven (one slot is reserved for future expansion) Fibre Channel cards. Each card connects a FC port to two Ultra-2 SCSI ports. The IM also contains a Remote Management Card (RMC) in slot 1, and a controller card in slot 2. The RMC provides the user with a serial port for initial setup, as well as Telnet and Web Administrator - HTTP access to any of the cards in the IM.

Each FC card translates the FC protocol (FCP) to and from the SCSI protocol so that FC and SCSI devices can communicate. The FC card attaches to a FC host, hub, or switch and transfers the command, data, and status information to SCSI targets. Packets are transferred transparently by the IM between a host and targets and vice versa.

SCSI and Fibre Channel connectors are accessed from the front of the IM. Ethernet and serial ports provide the means for configuring and managing the IM. A power connector is located on the front of the Interface Manager.

12 Introduction Chapter 1

Figure 1 shows the front view of the Interface Manager.

Figure 1 Front View of the Interface Manager

Chapter 1

Table 1 Features of the Interface Manager

Number Part

1Serial DB-9 connector for terminal access

2 Ethernet RJ-45 connector for FTP, Telnet and Web browser access

3Remote management card

4 Controller card

5 Slots for Fibre Channel interface cards

6 Reserved slot

7 Redundant power supply

Chapter 1 Introduction 13

Processing SCSI Information

The following section describes how the Interface Manager (IM) processes SCSI information when attached to Fibre Channel (FC) hosts.

1. A FC host issues a command. The FC host encapsulates the SCSI command in the FC protocol and sends the packet to the IM.

2. The FC card in the IM receives the packet, interprets the FC information, and places the packet in buffer memory.

3. The IM’s processor interprets the information and programs a SCSI controller to process the transaction.

4. The SCSI controller sends the command to the SCSI device (target).

5. The SCSI target interprets the command and executes it.

6. Data flows between the FC host and SCSI target through payload buffers.

7. Response information flows from the SCSI target back to the FC host.

14 Introduction Chapter 1

Interface Manager (IM) Features

Fibre Channel Features

■ Fibre Channel target mode

■ Single 1.0625 Gbps FC port

■ Fibre Channel arbitrated loop (FC-AL) and switched fabric (FC-SW)

topologies, includes point-to-point (PPP) configurations

■ Private Loop Direct Attach (PLDA) profile compliant

■ Class 3 connection with SCSI-FCP protocol

■ Supports FCP-2 error recovery protocol as specified in FCP-2 rev. 03 for

use with streaming devices (such as tape) and medium changers

SCSI Bus Features

■ SCSI initiator mode

■ Up to 20 auto-negotiating SCSI buses (Narrow, Wide, Fast, Ultra)

■ Ultra-2 wide SCSI for data transfer up to 80MB/s per bus (LVD)

■ Ultra-2 wide SCSI for data transfer up to 40MB/s per bus (HVD)

Chapter 1

■ SCSI-2 and SCSI-3 protocols

■ Differential or LVD/single-ended internal termination

(HVD or LVD Single-ended)

■ Supports tape and medium changer SCSI devices

Configuration Features

■ DHCP for easier network administration

■ Serial DB-9 connector for terminal access

■ Ethernet RJ-45 connector for FTP, Telnet and Web browser access

■ Field-upgradeable firmware

Chapter 1 Introduction 15

Management Features

■ Out-of-band Ethernet TCP/IP management access

■ In-Band management

16 Introduction Chapter 1

Interface Manager (IM) Components

This section includes a list of all parts supplied with the IM.

Supplied Components for the Interface Manager

Figure 2 Supplied Components

Chapter 1

Chapter 1 Introduction 17

Table 2 Supplied Components

No. Item Qty Description

1 HP Surestore Interface Manager 1 Base Product: Chassis, Interface Manager controller,

remote management card, power supply and three fans

2 Mounting rails 2 Left and right mounting rails

3 Mounting rail extensions 2 Used for the 10/180 tape library only

4 Hardware identification board 1 Hardware consisting of:

6 - 10x32 hex nuts 12 - sheet metal nuts 16 - 10x32 x 50 machine screws

5 Flush mount brackets 2 Left and right flush mount brackets

6 Cable labeling kit 1 Label kit to label the SCSI and fibre cables

7 Power distribution unit 1 Power distribution unit

8 HP Surestore Interface Manager

Installation and Cabling Poster

9 HP Surestore Interface Manager

User’s Guide

10 Serial cable 1 Serial cable

11 Power cord 1 power cord (PDU to the Interface Manager)

12 SCSI cable 1 2.5 meter FC SCSI cable for daisy chaining the robotics to

13 Localized power cord 1 Localized power cord (wall to PDU)

18 Introduction Chapter 1

1 Installation and Cabling Poster

1User’s Guide

a drive - High Density - Do not use with the Interface Manager

Specifications

This section includes information on the physical and environmental specifications for the Interface Manager.

Physical Specifications of the Interface Manager (IM)

The IM is installed inside the accessory bin of the 10/180 and 20/700 HP tape libraries.

The physical characteristics are as follows:

Table 3 Physical Specifications of the Interface Manager

Height 8.48 inches (21.2 cm)

Width 17.26 inches (43.15 cm)

Depth 10.78 inches (26.95 cm)

Chapter 1

Weight (to include box with fans, redundant power supply, Interface Manager controller and RMC boards and 11 slot covers)

Environmental Specifications

Choose a location that meets the following criteria:

Table 4 Location Criteria

Room temperature 50

Humidity 20% to 80% relative humidity, non-condensing

Power source AC power voltage: 100-127 VAC/200-240VAC

Approximately 34.2 pounds (15.54 kg)

- 95o Farenheit (10o - 35o C)

50-60 Hz

Chapter 1 Introduction 19

Supported Products

Table 5 shows the products that Hewlett-Packard supports for connection with

the Interface Manager:

Table 5 Supported Products

Description Product

HP SureStore E Tape Libraries: 10/180 and 20/700 with Ultrium, DLT 7000, DLT 8000, and 9840 tape drives

HP Fibre Channel Switches Brocade SilkWorm 2800 - A5624A

QLogic Fibre Channel HBA Win NT 4.0, Windows 2000, Netware 5.x - QLA-2200F

Emulex HBA Win NT 4.0, Windows 2000 - LP8000-N1, LP8000-F1

Compaq HBA Win NT 4.0, Windows 2000 - 176479-B21

10/180 - A5617A 20/700 - A5597A, A5597B

Brocade SilkWorm 2400 - A5625A

20 Introduction Chapter 1

Table 5 Supported Products

Description Product

HP Fibre Channel Host Bus Adapters HP-UX 11.11,11.0 A5158A (pci)

HP-UX 11.11,11.0, 10.20 A6685A (hsc-K class), A6684A (hsc-D, R class)

A6684A and A6685A adapters are only supported on the following R, D, and K-class servers:

A6684A Supported Platforms:

R-class R380.R390

D-class D220.D230/D320/D330

D270/D280/D370/D380/D390

A6685A Supported Platforms:

K-class K220/K420/K250/K450/K260/K360/

K370/K380/K460/K570/K580

HP-UX 11.0; V, N & L Class - A5158A HP-UX 10.20 & 11.0; T600 - A3636A HP-UX 10.20 & 11.0; D & R Class - A3591B HP-UX 10.20 & 11.0; K Class - A3404A Win NT 4.0, Windows 2000 - D8602A Win NT 4.0 SP 4 & above; HP Netserver - D8602A/B Win NT 4.0 SP 4 & above; Compaq Proliant - D8602A/B Win NT 4.0 SP 4 & above; Dell PowerEdge - D8602A/B Win NT 4.0 SP 4 & above; IBM Netfinity - D8602A/B

Chapter 1

Sun Solaris 2.6, 7, 8 JNI FC64-1063N (sbus)

JNI FCI-1063 (pci) JNI FCE-1063-N (sbus) FCE-6410-N (pci)

Note DLT 7000 tape drives are only supported in the 20/700 tape

library.

Chapter 1 Introduction 21

Note The A3636A, A3591B and the A3404A FC HBA are only

supported in point-to-point (PPP) configurations (not through a switch).

Note HVD SCSI tape drives (DLT 7000, DLT 8000, 9840, and the

HVD version of Ultrium) should only be attached to HVD SCSI ports on the Interface Manager.

Optical Fibre Channel Cables

The Interface Manager uses the following fiber-optic cables available in the lengths listed in Table 6.

Table 6 Fibre-Optic Cable Lengths

Product Number Length

A3583A FC Optical Cable 2 meters

A3531A FC Optical Cable 16 meters

A3735A FC Optical Cable 50 meters

A3736A FC Optical Cable 100 meters

A5225A SW Optical/GBIC N/A

22 Introduction Chapter 1

Interface Manager Overview

Chapter Overview

This chapter contains information on the following:

■ Overview of the Interface Manager (IM) Configuration on page 24

■ Choosing the Right Configuration on page 25

Chapter Overview 23

Overview of the Interface Manager (IM) Configuration

The IM can be configured through one of several user interfaces:

■ Over a serial port via a terminal or terminal emulation utility

■ Over Ethernet via a Telnet utility, Internet Web browser, or SNMP

management tool

Note Before configuring the Interface Manager, a basic understanding

of Fibre Channel and SCSI devices is recommended.

For information on SCSI standards, refer to publications from the X3T10 committee of ANSI (American National Standards Institute). For information on Fibre Channel standards, refer to publications from the X3T11 committee of ANSI. Approved American National Standards and Technical Reports may be purchased from:

ANSI 11 West 42nd Street 13th Floor New York, NY 10036 Sales Department: (212) 642-4900

24 Overview of the Interface Manager (IM) Configuration Chapter 2

Choosing the Right Configuration

The factory default settings of the Interface Manager (IM) permit the type of configuration shown in Figure 3 on page 26 (standard configuration) to work without any initial changes to these settings. The IM settings may need to be changed for expanded configurations (see Figure 4 on page 27) or certain application requirements.

Chapter 2

Chapter 2 Choosing the Right Configuration 25

Figure 3 Example of a Standard Configuration in a 20/700 Tape Library

26 Choosing the Right Configuration Chapter 2

Figure 4 Expanded Configuration

Chapter 2

Chapter 2 Choosing the Right Configuration 27

A standard configuration may involve several Fibre Channel (FC) hosts connected to multiple FC cards. These FC host systems may be connected to the cards either in a point-to-point (PPP) fashion or through a FC switch. Each card is then connected to two SCSI tape drives.

The library’s robotics controller may be daisy-chained with one of the SCSI tape drives or connected directly to an available FC interface card SCSI port, or direct connect SCSI to host.

Note When daisy-chaining the library’s robotics controller to any LVD

Fibre Channel Port Mode

The IM’s Fibre Channel ports can operate in either NL_Port or N_Port mode. The IM has the ability to autosense and choose between these modes of operation.

■ NL_Port - The IM can share a FC Arbitrated Loop with other NL_Port

devices (or HBAs). A single FC switch port acting in FL_Port mode can also be connected to the loop.

■ N_Port - The IM does not employ the arbitrated loop protocol. This allows

for a more efficient connection to a single FC switch port acting in F_Port mode.

Some FC switches (such as the HP/Brocade SilkWorm) support either FL_Port and F_Port modes with autosensing capabilities. Other switches (such as the HP Surestore Director) only support the F_Port mode. When connecting directly to a FC switch port, configure the IM in N_Port mode for a more stable and efficient connection.

Port mode can only be set in the FC Configuration menu via the Telnet interface. See Configuration Using the Telnet Interface on page 38.

tape drive, the library must have the LVD to HVD converter (A6324A) installed.

28 Choosing the Right Configuration Chapter 2

Fibre Channel Arbitrated Loop Addressing

On a FC arbitrated loop, each device appears as an Arbitrated Loop Physical Address (AL_PA). To obtain an AL_PA, two methods called soft and hard addressing can be used by the IM. The IM can be configured to use either method.

Hard Addressing

Hard addressing is recommended for FC arbitrated loop environments where it is important that the FC device addresses do not change. Device address changes can affect the mapping represented by the host operating system to the application. An example of such an environment would be a tape library installation, where the application configuration requires fixed device identification for proper operation. Hard addressing ensures that the device identification to the application remains constant.

When acquiring a hard address, the IM attempts to acquire the AL_PA value that was specified by user configuration. If the desired address is not available at loop initialization time, the IM will come up on the FC loop using an available soft address. This allows the loop to continue to operate. This situation would occur when another device on the arbitrated loop has acquired the same address as that configured on the IM.

When connected to a FC switch, the IM is identified to the switch as a unique device by the factory programmed World Wide Name (WWN).

Soft Addressing

Soft addressing is recommended for FC fabric environments where the FC interface card does not employ the Arbitrated Loop protocol. In these environments, an AL_PA is not used as part of the device address, so soft addressing allows the FC interface card to operate as an N_Port. Soft addressing is recommended primarily for switched fabric configurations.

When acquiring a soft address, the FC interface card acquires the first available loop address starting from address 01 and moving up the list of available AL_PAs to EF. In this mode, the FC interface card automatically obtains an available address and participates on the FC loop, as long as there is at least one address available on the loop that is connected to the IM. FC supports up to 126 devices on an arbitrated loop.

Chapter 2

Chapter 2 Choosing the Right Configuration 29

Host Device Configuration

The host system using a FC host bus adapter (HBA) will typically map FC devices into the existing device mapping scheme used by that operating system. (Refer to your HBA manual for the mapping table.) The FC usually maps FC addresses to SCSI target addresses. In such a configuration, the IM corresponds to a bus:target identifier, with the SCSI devices attached to the IM appearing as logical units (LUNs). In addition, operating systems can extend the available SCSI limit of 15 Target IDs per bus.

Although this is not an issue for the operating system or most applications, there are cases where older applications or Windows NT can have expectations about what are valid SCSI IDs, and not deal correctly with certain mappings. In particular, applications have been seen to exhibit difficulties addressing Target IDs greater than 15 (e.g. 16 and up). This problem can be resolved by configuring the IM to use hard addressing, and setting the AL_PA used by the IM to a value that the HBA will map to, with an ID having a value less than 16.

SCSI Addressing

A FC interface card appears on each SCSI bus as a single initiator. The default initiator ID is 7. No other device on the SCSI bus may use this address. Note that the FC host itself is not connected to the bus. Their SCSI operations are passed down to the individual SCSI target devices through the use of the IM’s SCSI Initiator ID.

The IM negotiates for the maximum values for transfer rates and bandwidth on a SCSI bus. If an attached SCSI device does not allow the full rates, the IM will use the best rates it can negotiate for that device. Negotiation is on a device specific basis, so the IM can support a mix of SCSI device types on the same SCSI bus.

Buffered Tape Writes

Buffered Tape Writes is an option designed to enhance system performance. By returning status on consecutive write commands prior to the tape device receiving data, Buffered Tape Writes remove the latency of waiting for responses from the tape device. In the event that data does not transfer correctly for any reason, the interface card will return a check condition on a subsequent command.

30 Choosing the Right Configuration Chapter 2

+ 160 hidden pages