Avago Technologies SATA 150-4 User Manual

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USER’S

GUIDE

MegaRAID

Configuration Software

March 2006

Version 2.0

DB15-000269-01

This document contains proprietary information of LSI Logic Corporation. The information contained herein is not to be used by or disclosed to third parties without the express written permission of an ofﬁcer of LSI Logic Corporation.

LSI Logic products are not intended for use in life-support appliances, devices, or systems. Use of any LSI Logic product in such applications without written consent of the appropriate LSI Logic ofﬁcer is prohibited.

Purchase of I Associated Companies, conveys a license under the Philips I use these components in an I

C standard Speciﬁcation as deﬁned by Philips.

the I

C components of LSI Logic Corporation, or one of its sublicensed

C system, provided that the system conforms to

C Patent Rights to

Document DB15-000269-01, Second Edition (March 2006) This document describes LSI Logic Corporation’s MegaRAID software tools and utilities. This document will remain the ofﬁcial reference source for all revisions/releases of these products until rescinded by an update.

LSI Logic Corporation reserves the right to make changes to any products herein at any time without notice. LSI Logic does not assume any responsibility or liability arising out of the application or use of any product described herein, except as expressly agreed to in writing by LSI Logic; nor does the purchase or use of a product from LSI Logic convey a license under any patent rights, copyrights, trademark rights, or any other of the intellectual property rights of LSI Logic or third parties.

LSI Logic, the LSI Logic logo design, FlexRAID, MegaRAID, MegaRAID Conﬁguration Utility, MegaRAID Manager, and Power Console Plus are trademarks or registered trademarks of LSI Logic Corporation. Intel and Pentium are registered trademarks of Intel Corporation. Linux is a registered trademark of Linus Torvalds. Microsoft, MS-DOS, Windows, and Windows NT are registered trademarks of Microsoft Corporation. NetWare,Novell, and SUSE are trademarks or registered trademarks of Novell, Inc. PCI-X is a registered trademark of PCI SIG. Red Hat is a registered trademark of Red Hat Software, Inc. All other brand and product names may be trademarks of their respective companies.

To receive product literature, visit us at http://www.lsilogic.com. For a current list of our distributors, sales ofﬁces, and design resource

centers, view our web page located at

http://www.lsilogic.com/contacts/index.html

Preface

Audience

This book is the primary reference and user’s guide for the MegaRAID software tools and utilities. These include the MegaRAID BIOS Conﬁguration Utility (CU), WebBIOS CU, MegaRAID Manager™, and Power Console Plus™, which enable conﬁguration and management of RAID systems using the MegaRAID controllers.

This document assumes that you have familiarity with storage systems, and are knowledgeable about PCI, SCSI, and Serial ATA interfaces. It also assumes that you are familiar with computer systems and know how to use the keyboard, mouse, clipboard functions, toolbars, and drop down menus.

The people who beneﬁt from this book are:

• Users who want to conﬁgure, monitor, or manage RAID systems that

use MegaRAID controllers

• Engineers and managers who are evaluating MegaRAID controllers

for use in a system

• Engineers who are designing MegaRAID controllers into a system

Organization

This document has the following chapters and appendix:

• Chapter 1, Overview, introduces the MegaRAID software tools and

utilities, and provides operating system information.

• Chapter 2, Introduction to RAID, describes the components,

functions and beneﬁts of RAID, along with RAID levels, conﬁguration strategies, and conﬁguration planning.

MegaRAID Conﬁguration Software User’s Guide iii

• Chapter 3, BIOS Conﬁguration Utility and MegaRAID Manager,

describes the MegaRAID BIOS CU.

• Chapter 4, WebBIOS Conﬁguration Utility, describes the

WebBIOS CU.

• Chapter 5, Start the Power Console Plus Utility, describes the

Power Console Plus tool.

• Chapter 6, Virtual Sizing and Online Capacity Expansion,

describes the FlexRAID Virtual Sizing feature and capacity expansion under Linux.

• Appendix A, MegaRAID Service Monitor, describes the messages

used by the MegaRAID Service Monitor.

MegaRAID System Installation Sequences and Document Organization

The following table outlines the installation, conﬁguration, and management sequences for a MegaRAID Serial ATA system. Each sequence consists of a series of steps and operations that the reference manual explains. LSI Logic recommends performing the sequences in the order listed when you install and conﬁgure your Serial ATA system.

Sequence Task Reference Manual

1 Understand RAID system theory and operation. MegaRAID Conﬁguration

2 Install the MegaRAID Serial ATA (SATA) or SCSI storage

3 Conﬁgure the physical arrays and logical devices using

4 Install the MegaRAID device drivers. MegaRAID Device Driver

5 Manage, monitor, and reconﬁgure the RAID array using

iv Preface

adapter and the related hardware.

either the MegaRAID Conﬁguration Utility WebBIOS CU.

either the MegaRAID Manager tool or the Power Console Plus tool. Each tool runs under an operating system and can manage the RAID array while the system is operating.

™

(CU) or the

Software User’s Guide MegaRAID 320 Storage

Adapters User’s Guide, MegaRAID SATA150 PCI to Serial ATA Storage Adapters User’sGuide, and MegaRAID SATA 300 Storage Adapters User’s Guide

MegaRAID Conﬁguration Software User’s Guide

Installation User’s Guide MegaRAID Conﬁguration

Software User’s Guide

Related Publications

MegaRAID SA TA150 PCI to Serial ATA Storage Adapters User’s Guide

Document Number: DB15-000272-04

This document explains how to install your MegaRAID SATA 150 storage adapter in the host system. It provides the electrical and physical speciﬁcations, jumper deﬁnitions, and connector locations for the storage adapter.

MegaRAID SATA 300 Storage Adapters User’s Guide

Document Number: DB15-000311-02

This document explains how to install your MegaRAID SATA 300 storage adapter in the host system. It provides the electrical and physical speciﬁcations, jumper deﬁnitions, and connector locations for the storage adapter.

MegaRAID 320 Storage Adapters User’s Guide

Document Number: DB15-000260-06

This document explains how to install your MegaRAID 320 storage adapter in the host system. It provides the electrical and physical speciﬁcations, jumper deﬁnitions, and connector locations for the storage adapter.

MegaRAID Device Driver Installation User’s Guide

Document Number: DB11-000018-02

This document explains how to install the MegaRAID device driver for your operating system. The information in this document is independent of the back-end bus and applies to both MegaRAID SCSI storage adapters and Serial ATA storage adapters.

Preface v

Conventions

Throughout the manual, the following conventions are used to describe user interaction with the product.

Notation Meaning and Use Examples

→ Used to indicate a series of

all caps, plus sign

courier typeface

bold typeface fd1sp In a command line, keywords are shown in bold, nonitalic

italics module In command lines and names, italics indicate user

Initial Capital letters

brackets [version] You may, but need not, select one item enclosed within

selections in a GUI. Key presses are in all caps,

with a plus sign (+) between key presses in a sequence

.nwk ﬁle Names of commands, directories, ﬁle names, and

Undo Edit Apply

Start → Programs

ENTER, ALT+CTRL+DEL, TAB

on-screen text are shown in courier typeface.

typeface. Enter them exactly as shown.

variables. Italicized text must be replaced with appropriate user-speciﬁed items. Enter items of the type called for, using lowercase.

Names of menu commands, options, check buttons, text buttons, options buttons, text boxes, list boxes, etc., are shown in text with Initial Capital lettering to avoid misreading. These elements may appear on your screen in all lowercase.

brackets. Do not enter the brackets.

vi Preface

Revision History

Document Number Version/Date Description

DB15-000269-01 Version 2.0

February 2006

DB15-000269-00 Version 1.0

February 2003

Technical Support

LSI provides technical support only for LSI products purchased directly from LSI or from an LSI-authorized reseller.

If you purchased the MegaRAID controller from LSI or from a certiﬁed LSI reseller, call LSI technical support at support@lsil.com, 1-800-633-4545 #3, or 1-678-728-1250. Please be prepared to specify the 10-digit number preceded by the letter “E”.

In Europe, you can contact LSI Technical Support at eurosupport@lsil.com or +44.1344.413.441 (English).

If the MegaRAID controller was installed as part of a system manufactured by a company other than LSI, or if you purchased an LSI product from an unauthorized reseller, call the technical support department of the computer manufacturer or the unauthorized reseller. LSI does not provide direct technical support in these cases.

Added the introduction to RAID chapter. Revised supported operating systems, spanning, and menu options, and added port multiplier information in the BIOS Conﬁguration Utility. Revised information about virtual sizing. Revised the WebBIOS Adapter Properties Menu and the Conﬁguration Wizard procedure.

Initial release of document.

To download drivers or documentation, go to the LSI web site at:

http://www.lsilogic.com/downloads/selectDownload.do.

Preface vii

viii Preface

Chapter 1 Overview

1.1 MegaRAID Tool Description 1-1

1.1.1 MegaRAID BIOS Conﬁguration Utility (Ctrl+M) 1-2

1.1.2 MegaRAID Manager Conﬁguration Utility 1-2

1.1.3 WebBIOS Conﬁguration Utility (CTRL+H) 1-2

1.1.4 Power Console Plus Conﬁguration Utility 1-2

1.2 Operating System Support 1-3

Chapter 2 Introduction to RAID

2.1 RAID Description 2-1

2.2 RAID Beneﬁts 2-2

2.3 RAID Functions 2-2

2.4 RAID Components and Features 2-3

2.4.1 Physical Array 2-3

2.4.2 Logical Drive 2-3

2.4.3 RAID Array 2-3

2.4.4 Fault Tolerance 2-3

2.4.5 Consistency Check 2-4

2.4.6 Background Initialization 2-4

2.4.7 Patrol Read 2-5

2.4.8 Disk Striping 2-6

2.4.9 Disk Mirroring 2-7

2.4.10 Parity 2-7

2.4.11 Disk Spanning 2-8

2.4.12 Hot Spares 2-9

2.4.13 Disk Rebuilds 2-11

2.4.14 SCSI Physical Drive States 2-12

2.4.15 Logical Drive States 2-13

2.4.16 Enclosure Management 2-13

MegaRAID Conﬁguration Software User’s Guide ix

2.5 RAID Levels 2-13

2.5.1 Summary of RAID Levels 2-13

2.5.2 Selecting a RAID Level 2-14

2.6 RAID Conﬁguration Strategies 2-19

2.6.1 Maximizing Fault Tolerance 2-19

2.6.2 Maximizing Performance 2-21

2.6.3 Maximizing Storage Capacity 2-22

2.7 RAID Availability 2-23

2.7.1 Spare Drives 2-23

2.7.2 Rebuilding 2-23

2.8 RAID Conﬁguration Planning 2-24

2.8.1 Number of Physical Disk Drives 2-24

2.8.2 Array Purpose 2-25

Chapter 3 BIOS Conﬁguration Utility and MegaRAID Manager

3.1 Quick Conﬁguration Steps for the BIOS Conﬁguration Utility 3-2

3.2 Quick Conﬁguration Steps for MegaRAID Manager 3-3

3.3 Conﬁguration Utility Menu 3-4

3.3.1 Conﬁgure Menu 3-5

3.3.2 Initialize Option 3-6

3.3.3 Objects Menu 3-6

3.3.4 Clear Option 3-14

3.3.5 Rebuild Option 3-14

3.3.6 Check Consistency Option 3-15

3.3.7 Reconstruct Option 3-15

3.3.8 Select Adapter Menu 3-15

3.4 Detailed Conﬁguration Instructions 3-16

3.4.1 Starting the MegaRAID Conﬁguration Utility 3-16

3.4.2 Resolving a Conﬁguration Mismatch 3-16

3.4.3 Starting MegaRAID Manager 3-17

3.4.4 Conﬁguring Arrays and Logical Drives 3-18

3.4.5 Selecting a Conﬁguration Method 3-18

3.4.6 Designating Drives as Hot Spares 3-18

3.4.7 Creating Physical Arrays and Logical Drives 3-19

3.4.8 Initializing Logical Drives 3-26

x Contents

3.5 Deleting Logical Drives 3-27

3.6 Performing Drive Roaming 3-27

3.7 Performing Drive Migration 3-29

3.8 Rebuilding Failed Disks 3-30

3.8.1 Rebuild Types 3-30

3.8.2 Manual Rebuild – Rebuilding an Individual Drive 3-31

3.8.3 Manual Rebuild – Rebuilding in Batch Mode 3-31

3.9 FlexRAID Virtual Sizing 3-32

3.10 Checking Data Consistency 3-32

3.11 Reconstructing Logical Drives 3-33

3.12 Replacing a Failed Controller Containing Data in the TBBU 3-34

3.13 Using a Preloaded System Drive 3-35

3.14 Exiting MegaRAID Conﬁguration Utility 3-36

Chapter 4 WebBIOS Conﬁguration Utility

4.1 General Description 4-1

4.2 Quick Conﬁguration Steps 4-2

4.3 Starting the WebBIOS Conﬁguration Utility on the Host Computer 4-2

4.4 Screen and Option Descriptions 4-4

4.4.1 WebBIOS Toolbar Options 4-4

4.4.2 Main Screen 4-5

4.4.3 Adapter Properties Screen 4-6

4.4.4 Scan Devices Option 4-9

4.4.5 SCSI Channel Properties 4-9

4.4.6 Logical Drive Screen 4-9

4.4.7 Physical Drive Screen 4-12

4.4.8 Conﬁguration Mismatch Screen 4-13

4.4.9 Conﬁguration Wizard Option 4-14

4.4.10 Adapter Selection Option 4-14

4.4.11 Physical View/Logical View Option 4-14

4.4.12 Exit 4-14

4.5 Conﬁguring RAID Arrays and Logical Drives 4-14

Contents xi

Chapter 5 Start the Power Console Plus Utility

5.1 Quick Conﬁguration Steps 5-1

5.2 Power Console Plus Overview 5-2

5.2.1 Power Console Plus Components 5-2

5.2.2 Features 5-3

5.2.3 Client System Requirements 5-4

5.2.4 MegaService Monitor 5-4

5.3 Installing the Power Console Plus Utility 5-5

5.3.1 Windows Installations 5-5

5.3.2 Deregistering and Reregistering under

the Power Console Plus Utility 5-11

5.4 Power Console Plus Interface Description 5-11

5.4.1 Power Console Plus Main Window Description 5-12

5.4.2 Power Console Plus Menus 5-14

5.4.3 Physical Drive Menu 5-16

5.4.4 Logical Drive Menu 5-17

5.4.5 Progress Menu 5-18

5.5 Conﬁguring Arrays and Logical Drives 5-19

5.5.1 Starting the Power Console Plus Utility 5-19

5.5.2 Choosing an Adapter 5-20

5.5.3 Running the Conﬁguration Wizard 5-20

5.5.4 Deﬁning Logical Drives 5-22

5.5.5 Saving the Conﬁguration 5-24

5.5.6 Initializing Logical Drives 5-25

5.5.7 Checking Rebuild Rate 5-25

5.5.8 Exiting the Power Console Plus Utility 5-25

5.6 Reclaiming Hot Spare Disks 5-25

5.7 Reconﬁguring Existing Arrays 5-26

5.7.1 Adding a Physical Drive to an Existing Array 5-26

5.7.2 Removing a Physical Drive from an Array 5-26

5.8 Add Capacity Steps 5-27

Chapter 6 Virtual Sizing and Online Capacity Expansion

6.1 FlexRAID Virtual Sizing 6-1

6.2 Capacity Expansion under the Linux Operating System 6-2

xii Contents

Appendix A MegaRAID Service Monitor

A.1 Power Console Plus Internal Messages A-1 A.2 MegaRAID Service Monitor Event Types A-3 A.3 Event Message IDs A-7

Index

Customer Feedback

Contents xiii

xiv Contents

Figures

2.1 Disk Striping (RAID 0) Example 2-6

2.2 Disk Mirroring (RAID 1) Example 2-7

2.3 Distributed Parity (RAID 5) Example 2-8

2.4 Disk Spanning (RAID 10) Example 2-9

2.5 RAID 10 Logical Drive 2-17

2.6 RAID 50 Logical Drive 2-19

3.1 MegaRAID Conﬁguration Utility Menu Tree 3-4

3.2 Port Multiplier Option 3-9

3.3 Port and Drive Information 3-9

4.1 WebBIOS Adapter Selection Screen 4-3

4.2 WebBIOS Main Screen 4-5

4.3 WebBIOS Adapter Properties Screen 4-6

4.4 WebBIOS Logical Drive Screen 4-10

4.5 WebBIOS Physical Drive Screen 4-12

4.6 WebBIOS Conﬁguration Mismatch Screen 4-13

4.7 WebBIOS Conﬁguration Wizard Screen 4-15

4.8 WebBIOS Logical Drive Deﬁnition Screen 4-16

xvi

Tables

1.1 MegaRAID Tool Operating System Support 1-3

2.1 Types of Parity 2-8

2.2 Disk Spanning for RAID 10 and RAID 50 2-9

2.3 SCSI Physical Drive States 2-12

2.4 Logical Drive States 2-13

2.5 RAID 0 Overview 2-15

2.6 RAID 1 Overview 2-15

2.7 RAID 5 Overview 2-16

2.8 RAID 10 Overview 2-17

2.9 RAID 50 Overview 2-18

2.10 RAID Levels and Fault Tolerance 2-20

2.11 RAID Levels and Performance 2-21

2.12 RAID Levels and Capacity 2-22

2.13 Physical Drives Required for Each RAID Level 2-24

2.14 Factors to Consider for Array Conﬁguration 2-25

3.1 Conﬁguration Utility Conﬁgure Menu 3-5

3.2 Conﬁguration Utility Objects Menu 3-6

3.3 Conﬁguration Utility Adapter Submenu 3-7

3.4 Conﬁguration Utility Logical Drive Submenu 3-10

3.5 Conﬁguration Utility View/Update Parameters Submenu 3-11

3.6 Conﬁguration Utility Physical Drive Submenu 3-13

3.7 Conﬁguration Utility Channel Submenu 3-13

3.8 Conﬁguration Utility Battery Backup Submenu 3-14

3.9 Conﬁguration Hot Keys 3-16

3.10 Logical Drive Parameters and Descriptions 3-21

3.11 Spanning Mode Options 3-25

3.12 Rebuild Types 3-30

4.1 WebBIOS Toolbar Icon Descriptions 4-4

4.2 WebBIOS Adapter Properties Menu Options 4-7

5.1 Power Console Plus Screen Elements 5-12

5.2 Power Console Plus Toolbar Icons 5-13

5.3 Power Console Plus Conﬁguration Menu 5-14

5.4 Power Console Plus Adapter Properties Menu 5-15

5.5 Power Console Plus Physical Drive Menu 5-16

5.6 Power Console Plus Change Status Submenu 5-16

5.7 Power Console Plus Logical Drive Menu 5-17

xvii

5.8 Power Console Plus Change Conﬁguration Submenu 5-17

5.9 Power Console Plus Read Policy Menu 5-18

5.10 Power Console Plus Write Policy Menu 5-18

5.11 Drive State Description 5-19

5.12 Custom Conﬁguration Wizard Options 5-21

A.1 Log Messages A-2 A.2 General Events Types and Log Messages A-3 A.3 Logical Drive Status Messages A-4 A.4 Physical Drive Status and Error Messages A-4 A.5 Messages for SAF-TE Compliant Boxes A-5 A.6 Battery Status Messages A-6 A.7 General Event Message IDs A-7 A.8 Test-Related Event Message IDs A-7

xviii

Chapter 1 Overview

This book describes the following software tools and utilities that enable conﬁguration and management of RAID systems using the MegaRAID controllers:

• MegaRAID BIOS Conﬁguration Utility (CU)

• WebBIOS CU

• MegaRAID Manager

• Power Console Plus

This chapter provides an overview of the MegaRAID software tools and explains the intended use of each tool. It consists of the following sections:

• Section 1.1, “MegaRAID Tool Description”

• Section 1.2, “Operating System Support”

1.1 MegaRAID Tool Description

MegaRAID products provide a powerful set of software products for conﬁguring and managing Redundant Array of Independent Disks (RAID) systems. The following subsections describe each software product. Subsequent chapters provide detailed information concerning each product.

You can use any of the listed utilities to conﬁgure your RAID system. Or, you can conﬁgure your RAID system with one utility and update it later with a different utility. All MegaRAID tools provide a full set of RAID array conﬁguration and monitoring features.

MegaRAID Conﬁguration Software User’s Guide 1-1

1.1.1 MegaRAID BIOS Conﬁguration Utility (Ctrl+M)

The MegaRAID BIOS Conﬁguration Utility (CU) provides full-featured, character-based conﬁguration and management of RAID arrays. The MegaRAID CU resides in the BIOS and is independent of the operating system. For information about the BIOS CU, refer to Chapter 3, “BIOS

Conﬁguration Utility and MegaRAID Manager.”

1.1.2 MegaRAID Manager Conﬁguration Utility

The MegaRAID Manager utility provides full-featured conﬁguration and management of RAID arrays. The MegaRAID Manager utility enables conﬁguration and management of RAID systems while the operating system is running. The MegaRAID Manager utility provides the same feature set as the MegaRAID CU. For information about MegaRAID Manager, refer to Chapter 3, “BIOS Conﬁguration Utility and

MegaRAID Manager.”

1.1.3 WebBIOS Conﬁguration Utility (CTRL+H)

The WebBIOS CU tool provides full-featured, html-based conﬁguration and management of RAID arrays. WebBIOS resides in the BIOS and is independent of the operating system. The WebBIOS CU provides the same feature set as the MegaRAID CU. In addition, it allows you to add drives and migrate between RAID levels. For information about the WebBIOS CU, refer to Chapter 4, “WebBIOS Conﬁguration Utility.”

1.1.4 Power Console Plus Conﬁguration Utility

The Power Console Plus utility provides on-the-ﬂy RAID migration, creating almost limitless adaptability and expansion of any logical drive while the system remains operational. For information about the Power Console Plus utility, refer to Chapter 5, “Start the Power Console

Plus Utility.”

The Power Console Plus utility is an object-oriented GUI utility that conﬁgures and monitors RAID systems locally or over a network. The Power Console Plus manager runs on the Microsoft Windows NT, Windows 2000, Windows XP, and Windows Server 2003 operating systems. With the Power Console Plus manager, you can perform the same tasks as with the MegaRAID Manager.

1-2 Overview

1.2 Operating System Support

Table 1.1 lists the operating system support for each of the

MegaRAID tools.

Table 1.1 MegaRAID Tool Operating System Support

MegaRAID Tool Supported Operating Systems

BIOS CU Operating system (OS) support is not required. The CU

MegaRAID Manager MS-DOS, Novell NetWare, Red Hat Linux, SUSE Linux

WebBIOS CU OS support is not required. The CU runs from the BIOS. Power Console Plus Windows 2000, Windows XP, Windows Server 2003.

runs from the BIOS.

Enterprise Server (SLES).

Note: For information about drivers forthe operating systems, refer

to the MegaRAID Device Driver Installation User’s Guide.

Operating System Support 1-3

1-4 Overview

Chapter 2 Introduction to RAID

This chapter describes RAID features and the advantages that RAID systems offer in terms of fault tolerance, improved I/O performance, and data storage reliability. In addition, it discusses RAID conﬁguration strategies and planning.

This chapter consists of the following sections:

• Section 2.1, “RAID Description”

• Section 2.2, “RAID Beneﬁts”

• Section 2.3, “RAID Functions”

• Section 2.4, “RAID Components and Features”

• Section 2.5, “RAID Levels”

• Section 2.6, “RAID Conﬁguration Strategies”

• Section 2.7, “RAID Availability”

• Section 2.8, “RAID Conﬁguration Planning”

2.1 RAID Description

RAID is an array of multiple independent hard disk drives that provides high performance and fault tolerance. The RAID array appears to the host computer as a single storage unit or as multiple logical units. Data throughput improves because several disks can be accessed simultaneously. RAID systems also improve data storage availability and fault tolerance. Data loss caused by a hard drive failure can be recovered by rebuilding missing data from the remaining data or parity drives.

MegaRAID Conﬁguration Software User’s Guide 2-1

2.2 RAID Beneﬁts

RAID systems improve data storage reliability and fault tolerance compared to single-drive storage systems. Data loss resulting from a hard drive failure can be prevented by reconstructing missing data from the remaining hard drives. RAID has gained popularity because it improves I/O performance and increases storage subsystem reliability.

2.3 RAID Functions

Logical drives, also known as virtual disks, are arrays or spanned arrays that are available to the operating system. The storage space in a logical drive is spread across all the physical drives in the array.

Note: The maximum logical drive size for all supported RAID

Your SCSI hard drives must be organized into logical drives in an array and must be able to support the RAID level that you select. Following are some common RAID functions:

• Creating hot spare drives.

levels (0, 1, 5, 10, and 50) is 2 Tbytes. You can create multiple logical drives on the same physical disks.

• Conﬁguring physical arrays and logical drives.

• Initializing one or more logical drives.

• Accessing controllers, logical drives, and physical drives individually.

• Rebuilding failed hard drives.

• Verifying that the redundancy data in logical drives using RAID level

1, 5, 10, or 50 is correct.

• Reconstructing logical drives after changing RAID levels or adding a

hard drive to an array.

• Selecting a host controller to work on.

2-2 Introduction to RAID

2.4 RAID Components and Features

RAID levels describe a system for ensuring the availability and redundancy of data stored on large disk subsystems. See Section 2.5,

“RAID Levels,” page 2-13 for detailed information about RAID levels.

2.4.1 Physical Array

A physical array is a group of physical disk drives. The physical disk drives are managed in partitions known as logical drives.

2.4.2 Logical Drive

A logical drive is a partition in a physical array of disks that is made up of contiguous data segments on the physical disks. A logical drive can consist of an entire physical array, more than one entire physical array, a part of an array, parts of more than one array, or a combination of any two of these conditions.

Note: The maximum logical drive size for all supported RAID

levels (0, 1, 5, 10, and 50) is 2 Tbytes. You can create multiple logical drives within the same physical array.

2.4.3 RAID Array

A RAID array is one or more logical drives controlled by the RAID controller.

2.4.4 Fault Tolerance

Fault tolerance is the capability of the subsystem to undergo a single failure without compromising data integrity, and processing capability. The RAID controller provides this support through redundant arrays in RAID levels 1, 5, 10 and 50. The system can still work properly even with a single disk failure in an array, through performance can be degraded to some extent.

Note: RAID level 0 is not fault-tolerant. If a drive in a RAID 0 array

RAID Components and Features 2-3

fails, the whole logical drive (all physical drives associated with the logical drive) fails.

Fault tolerance is often associated with system availability because it allows the system to be available during the failures. However, this means it is also important for the system to be available during repair.

A hot spare is an unused physical disk that, in case of a disk failure in a redundant RAID array, can be used to rebuild the data and re-establish redundancy. After the hot spare is automatically moved into the RAID array, the data is automatically rebuilt on the hot spare drive. The RAID array continues to handle requests while the rebuild occurs.

Auto-rebuild allows a failed drive to be replaced and the data automatically rebuilt by hot-swapping the drive in the same drive bay. The RAID array continues to handle requests while the rebuild occurs.

2.4.5 Consistency Check

The Consistency Check operation veriﬁes correctness of the data in logical drives that use RAID levels 1, 5, 10, and 50. (RAID 0 does not provide data redundancy.) For example, in a system with parity, checking consistency means computing the data on one drive and comparing the results to the contents of the parity drive.

Note: LSI recommends that you perform a consistency check at

least once a month.

2.4.6 Background Initialization

Background initialization is a consistency check that is forced when you create a logical drive. The difference between a background initialization and a consistency check is that a background initialization is forced on new logical drives. This is an automatic operation that starts 5 minutes after you create the drive.

Background initialization is a check for media errors on physical drives. It ensures that striped data segments are the same on all physical drives in an array. The background initialization rate is controlled by the rebuild rate set using the BIOS Conﬁguration Utility. The default, and recommended, rate is 30%. Before you change the rebuild rate, you must stop the background initialization or the rate change does not affect the background initialization rate. After you stop background initialization and change the rebuild rate, the rate change takes effect when you restart background initialization.

2-4 Introduction to RAID

2.4.7 Patrol Read

Patrol read involves the review of your system for possible hard drive errors that could lead to drive failure, then action to correct errors. The goal is to protect data integrity by detecting physical drive failure before the failure can damage data. The corrective actions depend on the array conﬁguration and type of errors.

Patrol read starts only when the controller is idle for a deﬁned period of time and no other background tasks are active, though it can continue to run during heavy I/O processes.

You can use the BIOS Configuration Utility to select the patrol read options, which you can use to set automatic or manual operation, or disable patrol read. Perform the following steps to select a patrol read option:

Step 1. Select Objects → Adapter from the Management Menu.

Step 2. Select Patrol Read Options from the Adapter menu. Step 3. The following options display:

The Adapter menu displays.

Patrol Read Mode Patrol Read Status Patrol Read Control

Step 4. Select Patrol Read Mode to display the patrol read options:

Manual – In manual mode, you must initiate the patrol read. Auto – In auto mode, the ﬁrmware initiates the patrol read on a

scheduled basis. Manual Halt – Use manual halt to stop the automatic operation,

then switch to manual mode. Disable – Use this option to disable the patrol read.

Step 5. If you use Manual mode, perform the following steps to initiate

a patrol read: a. Select Patrol Read Control and press ENTER. b. Select Start and press ENTER.

Note. Pause/Resume is not a valid operation when Patrol Read

is set to Manual mode.

RAID Components and Features 2-5

Step 6. Select Patrol Read Status to display the number of iterations

2.4.8 Disk Striping

Disk striping allows you to write data across multiple physical disks instead of just one physical disk. Disk striping involves partitioning each drive storage space into stripes that can vary in size from 8 Kbytes to 128 Kbytes. These stripes are interleaved in a repeated sequential manner. The combined storage space is composed of stripes from each drive. It is recommended that you keep stripe sizes the same across RAID arrays.

For example, in a four-disk system using only disk striping (used in RAID level 0), segment 1 is written to disk 1, segment 2 is written to disk 2, and so on. Disk striping enhances performance because multiple drives are accessed simultaneously, but disk striping does not provide data redundancy.

Figure 2.1 shows an example of disk striping.

completed, the current state of the patrol read (active or stopped), and the schedule for the next execution of patrol read.

Note: Do not install an operating system on a logical drive with

less than a 16 Kbyte stripe size.

Figure 2.1 Disk Striping (RAID 0) Example

Segment 1 Segment 5 Segment 9

2.4.8.1 Stripe Width

Stripe width is the number of disks involved in an array where striping is implemented. For example, a four-disk array with disk striping has a stripe width of four.

2-6 Introduction to RAID

Segment 2 Segment 6

Segment 10

Segment 3 Segment 7

Segment 11

Segment 4 Segment 8

Segment 12

2.4.8.2 Stripe Size

The stripe size is the length of the interleaved data segments that the RAID controller writes across multiple drives.

2.4.9 Disk Mirroring

With disk mirroring (used in RAID 1), data written to one disk is simultaneously written to another disk. If one disk fails, the contents of the other disk can be used to run the system and reconstruct the failed disk. The primary advantage of disk mirroring is that it provides 100% data redundancy. Because the disk contents are completely written to a second disk, it does not matter whether one of the disks fails. Both disks contain the same data at all times. Either drive can act as the operational drive.

Disk mirroring provides 100% redundancy, but is expensive because each drive in the system must be duplicated. Figure 2.2 shows an example of disk mirroring.

Figure 2.2 Disk Mirroring (RAID 1) Example

2.4.10 Parity

Segment 1 Segment 2 Segment 3 Segment 4 Segment 4 Duplicated

Segment 1 Duplicated Segment 2 Duplicated Segment 3 Duplicated

Parity generates a set of redundancy data from two or more parent data sets. The redundancy data can reconstruct one of the parent data sets. Parity data does not fully duplicate the parent data sets. In RAID, this method is applied to entire drives or stripes across all disk drives in an array. The types of parity are described in Table 2.1.

RAID Components and Features 2-7

Table 2.1 Types of Parity

Parity Type Description

Dedicated The parity of the data on two or more disk drives is stored on

Distributed The parity data is distributed across more than one drive in the

an additional disk.

system.

If a single disk drive fails, it can be rebuilt from the parity and the data on the remaining drives. RAID level 5 combines distributed parity with disk striping, as shown in Figure 2.3. Parity provides redundancy for one drive failure without duplicating the contents of entire disk drives, but parity generation can slow the write process.

Figure 2.3 Distributed Parity (RAID 5) Example

Segment 1 Segment 7

Parity (9–12)

Note: Parity is distributed across multiple drives in the array.

Segment 2 Segment 8

Segment 3 Segment 9

Parity (5–8)

Segment 4

Segment 10

2.4.11 Disk Spanning

Segment 5 Segment 11 Parity (1–4)

Segment 6

Segment 12

Disk spanning allows multiple physical drives to function like one big drive. Disk spanning overcomes lack of disk space and simpliﬁes storage management by combining existing resources or adding relatively inexpensive resources. For example, four 20 Gbyte drives can be combined to appear to the operating system as a single 80 Gbyte drive.

Spanning alone does not provide reliability or performance enhancements. Spanned logical drives must have the same stripe size and must be contiguous. In Figure 2.4, RAID 1 arrays are turned into a RAID 10 array.

Important: Make sure that the spans are in different backplanes, so

that if one span fails, you do not lose the whole array.

2-8 Introduction to RAID

Figure 2.4 Disk Spanning (RAID 10) Example

60 Gbytes/s 60 Gbytes/s

Can Be Accessed as

One 120 Gbyte/s Drive

60 Gbytes/s 60 Gbytes/s

Can Be Accessed as

One 120 Gbyte/s Drive

Note: Spanning two contiguous RAID 0 logical drives does not

produce a new RAID level or add fault tolerance. It increases the size of the logical volume and improves performance by doubling the number of spindles.

Disk Spanning for RAID 10 or RAID 50. Table 2.2 describes how to

conﬁgure RAID 10 and RAID 50 by spanning. The logical drives must have the same stripe size, and the maximum number of spans is eight. The full drive size is used when you span logical drives; you cannot specify a smaller drive size.

Table 2.2 Disk Spanning for RAID 10 and RAID 50

Level Description

10 Conﬁgure RAID 10 by spanning two contiguous RAID 1 logical drives.

50 Conﬁgure RAID 50 by spanning two contiguous RAID 5 logical drives.

The RAID 1 logical drives must have the same stripe size.

The RAID 5 logical drives must have the same stripe size.

2.4.12 Hot Spares

A hot spare is an extra, unused disk drive that is part of the disk subsystem. It is usually in standby mode, ready for service if a drive fails. Hot spares permit you to replace failed drives without system shutdown or user intervention. MegaRAID 320 controllers can implement automatic and transparent rebuilds of failed drives using hot spare drives, providing a high degree of fault tolerance and zero downtime.

RAID Components and Features 2-9

Note. When running RAID 0 and RAID 5 logical drives on the

same set of physical drives (a sliced conﬁguration), a rebuild to a hot spare does not occur after a drive failure until the RAID 0 logical drive is deleted.

The RAID management software allows you to specify physical drives as hot spares. When a hot spare is needed, the RAID controller assigns the hot spare that has a capacity closest to and at least as great as that of the failed drive to replace the failed drive. The failed drive is removed from the logical drive and marked ready awaiting removal after the rebuild to a hot spare begins. See Table 2.13 for detailed information about the minimum and maximum number of physical drives supported by each RAID level for each RAID controller. You can make hot spares of the physical drives that are not in a RAID logical drive.

Note: If a rebuild to a hot spare fails for any reason, the hot spare

There are two types of hot spares:

• Global Hot Spare

• Dedicated Hot Spare

2.4.12.1 Global Hot Spare

A global hot spare can replace any failed drive in a redundant array as long as its capacity is equal to or larger than the coerced capacity of the failed drive. A global hot spare deﬁned on any channel should be available to replace a failed drive on both channels.

drive is marked as failed. If the source drive fails, both the source drive and the hot spare drive are marked as failed.

2.4.12.2 Dedicated Hot Spare

A dedicated hot spare can replace a failed drive only in a selected array. One or more drives can be designated as member of a spare drive pool; the most suitable drive from the pool is selected for failover. A dedicated hot spare is used before one from the global hot spare pool.

Hot spare drives can be located on any RAID channel. Standby hot spares (not being used in RAID array) are polled every 60 seconds at a minimum, and their status is made available in the array management software. RAID controllers can rebuild with a disk that is in a system, but not initially set to be a hot spare.

Observe the following parameters when using hot spares:

2-10 Introduction to RAID

• Hot spares are used only in arrays with data redundancy, for

example, RAID levels 1, 5, 10, and 50.

• A hot spare connected to a speciﬁc RAID controller can rebuild a

drive that is connected to the same controller only.

• You must assign the hot spare to one or more drives through the

controller BIOS or use array management software to place it in the hot spare pool.

• A hot spare must have free space equal to or greater than the drive

it would replace. For example, to replace an 18 Gbyte drive, the hot spare must be 18 Gbytes or larger.

2.4.13 Disk Rebuilds

When a physical drive in a RAID array fails, you can rebuild the drive by recreating the data that was stored on the drive before it failed. The RAID controller uses hot spares to rebuild failed drives automatically and transparently, at user-deﬁned rebuild rates. If a hot spare is available, the rebuild can start automatically when a drive fails. If a hot spare is not available, the failed drive must be replaced with a new drive so the data on the failed drive can be rebuilt. Rebuilding can be done only in arrays with data redundancy, which includes RAID 1, 5, 10, and 50.

The failed physical drive is removed from the logical drive and marked ready awaiting removal after the rebuild to a hot spare begins. If the system goes down during a rebuild, the RAID controller automatically restarts the rebuild after the system reboots.

Note: When the rebuild to a hot spare begins, the failed drive is

often removed from the logical drive before management applications detect the failed drive. When this occurs, the events logs show the drive rebuilding to the hot spare without showing the failed drive. The formerly failed drive is marked as ready after a rebuild begins to a hot spare.

Note: If a rebuild to a hot spare fails for any reason, the hot spare

drive is marked as failed. If the source drive fails, both the source drive and the hot spare drive are marked as failed.

An automatic drive rebuild does not start if you replace a drive during an online capacity expansion or RAID level migration. The rebuild must be started manually after the expansion or migration procedure is complete.

RAID Components and Features 2-11

2.4.13.1 Rebuild Rate

The rebuild rate is the percentage of the compute cycles dedicated to rebuilding failed drives. A rebuild rate of 100 percent means the system gives priority to rebuilding the failed drives.

The rebuild rate can be conﬁgured between 0 and 100 percent. At 0 percent, the rebuild is done only if the system is not doing anything else. At 100 percent, the rebuild has a higher priority than any other system activity. LSI recommends not using 0 or 100 percent. The default rebuild rate is 30 percent.

2.4.13.2 Hot Swap

A hot swap is the manual replacement of a defective physical disk unit while the computer is still running. When a new drive has been installed, a rebuild occurs automatically if:

• The newly inserted drive is the same size as or larger than the

• The drive is placed in the same drive bay as the failed drive it

The RAID controller can be conﬁgured to detect the new disks and rebuild the contents of the disk drive automatically.

failed drive

is replacing

2.4.14 SCSI Physical Drive States

The SCSI Physical drive states are described in Table 2.3.

Table 2.3 SCSI Physical Drive States

State Description

Online The physical drive is working normally and is a part of a

Ready The physical drive is functioning normally but is not part of a

Hot Spare The physical drive is powered up and ready for use as a spare in

Fail A fault has occurred in the physical drive, placing it out of service. Rebuild The physical drive is being rebuilt with data from a failed drive.

2-12 Introduction to RAID

conﬁgured logical drive.

conﬁgured logical drive and is not designated as a hot spare.

case an online drive fails.

2.4.15 Logical Drive States

The logical drive states are described in Table 2.4.

Table 2.4 Logical Drive States

State Description

Optimal The logical drive operating condition is good. All conﬁgured

Degraded The logical drive operating condition is not optimal. One of the

Failed The logical drive has failed. Ofﬂine The logical drive is not available to the RAID controller.

physical drives are online.

conﬁgured physical drives has failed or is ofﬂine.

2.4.16 Enclosure Management

Enclosure management is the intelligent monitoring of the disk subsystem by software and/or hardware. The disk subsystem can be part of the host computer or can reside in an external disk enclosure. Enclosure management helps you stay informed of events in the disk subsystem, such as a drive or power supply failure. Enclosure management increases the fault tolerance of the disk subsystem.

2.5 RAID Levels

The RAID controller supports RAID levels 0, 1, 5, 10, and 50. The supported RAID levels are summarized in Section 2.5.1, “Summary of

RAID Levels.” In addition, it supports independent drives (conﬁgured as

RAID 0.) The following subsections describe the RAID levels in detail.

2.5.1 Summary of RAID Levels

RAID 0 uses striping to provide high data throughput, especially for large ﬁles in an environment that does not require fault tolerance.

RAID 1 uses mirroring so that data written to one disk drive is simultaneously written to another disk drive. This is good for small databases or other applications that require small capacity, but complete data redundancy.

RAID Levels 2-13

RAID 5 uses disk striping and parity data across all drives (distributed parity) to provide high data throughput, especially for small random access.

RAID 10, a combination of RAID 0 and RAID 1, consists of striped data across mirrored spans. It provides high data throughput and complete data redundancy, but uses a larger number of spans.

RAID 50, a combination of RAID 0 and RAID 5, uses distributed parity and disk striping and works best with data that requires high reliability, high request rates, high data transfers, and medium-to-large capacity. LSI does not recommend having RAID 0 and RAID 5 logical drives in the same physical array. If a drive in the physical array has to be rebuilt, the RAID 0 logical drive causes a failure during the rebuild.

2.5.2 Selecting a RAID Level

To ensure the best performance, you should select the optimal RAID level when you create a system drive. The optimal RAID level for your disk array depends on a number of factors:

• Number of physical drives in the disk array

• Capacity of the physical drives in the array

• Need for data redundancy

• Disk performance requirements

2.5.2.1 RAID 0

RAID 0 provides disk striping across all drives in the RAID array. RAID 0 does not provide any data redundancy, but does offer the best performance of any RAID level. RAID 0 breaks up data into smaller blocks and then writes a block to each drive in the array. The size of each block is determined by the stripe size parameter, set during the creation of the RAID set. RAID 0 offers high bandwidth.

Note: RAID level 0 is not fault-tolerant. If a drive in a RAID 0 array

fails, the whole logical drive (all physical drives associated with the logical drive) fails.

2-14 Introduction to RAID

By breaking up a large ﬁle into smaller blocks, the RAID controller can use several drives to read or write the ﬁle faster. RAID 0 involves no parity calculations to complicate the write operation. This makes RAID 0 ideal for applications that require high bandwidth but do not require fault tolerance. RAID 0 also denotes an independent or single drive.

Table 2.5 provides an overview of RAID 0.

Table 2.5 RAID 0 Overview

Feature Description

2.5.2.2 RAID 1

Uses Provides high data throughput, especially for large ﬁles. Any

environment that does not require fault tolerance.

Strong Points Provides increased data throughput for large ﬁles. No

capacity loss penalty for parity.

Weak Points Does not provide fault tolerance or high bandwidth. All data

lost if any drive fails.

Drives 1 to (14 drives x the number of channels).

In RAID 1, the RAID controller duplicates all data from one drive to a second drive. RAID 1 provides complete data redundancy, but at the cost of doubling the required data storage capacity.

Table 2.6 provides an overview of RAID 1.

Table 2.6 RAID 1 Overview

Feature Description Uses Appropriate for small databases or any other environment

that requires fault tolerance but small capacity.

Strong Points Provides complete data redundancy. RAID 1 is ideal for any

application that requires fault tolerance and minimal capacity.

Weak Points Requires twice as many disk drives. Performance is impaired

during drive rebuilds.

Drives 2

RAID Levels 2-15

2.5.2.3 RAID 5

RAID 5 includes disk striping at the block level and parity. In RAID 5, the parity information is written to several drives. RAID 5 is best suited for networks that perform a lot of small input/output (I/O) transactions simultaneously.

RAID 5 addresses the bottleneck issue for random I/O operations. Because each drive contains both data and parity, numerous writes can take place concurrently. In addition, robust caching algorithms and hardware-based, exclusive-or assist make RAID 5 performance exceptional in many different environments.

Table 2.7 provides an overview of RAID 5.

Table 2.7 RAID 5 Overview

Feature Description

2.5.2.4 RAID 10

Uses Provides high data throughput, especially for large ﬁles. Use

RAID 5 for transaction processing applications because each drive can read and write independently. If a drive fails, the RAID controller uses the parity drive to recreate all missing information. Use also for ofﬁce automation and online customer service that requires fault tolerance. Use for any application that has high read request rates but low write request rates.

Strong Points Provides data redundancy, high read rates, and good

performance in most environments. Provides data redundancy with lowest loss of capacity.

Weak Points Not well-suited to tasks requiring numerous writes. Suffers

more impact if no cache is used (clustering). Disk drive performance is reduced if a drive is being rebuilt. Environments with few processes do not perform as well because the RAID overhead is not offset by the performance gains in handling simultaneous processes.

Drives 3 to (14 drives x the number of channels).

RAID 10 is a combination of RAID 0 and RAID 1. RAID 10 consists of striped data across mirrored spans. RAID 10 breaks up data into smaller blocks, then mirrors the blocks of data to each RAID 1 set. Each RAID 1 set then duplicates its data to its other drive. The size of each block is determined by the stripe size parameter, which is set during the creation of the RAID set. Up to 8 spans can be supported by RAID 10.

2-16 Introduction to RAID

Table 2.8 provides an overview of RAID 10.

Table 2.8 RAID 10 Overview

Feature Description Uses Appropriate when used with data storage that needs 100%

redundancy of mirrored arrays and that also needs the enhanced I/O performance of RAID 0 (striped arrays.) RAID 10 works well for medium-sized databases or any environment that requires a higher degree of fault tolerance and moderate to medium capacity.

Strong Points Provides both high data transfer rates and complete data

redundancy.

Weak Points Requires twice as many drives as all other RAID levels

except RAID 1.

Drives 2n, where n is greater than 1.

In Figure 2.5, logical drive 0 is created by distributing data across four arrays (arrays 0 through 3). Spanning is used because one logical drive is deﬁned across more than one array. Logical drives deﬁned across multiple RAID 1 level arrays are referred to as RAID 10 logical drives. To increase performance, data is striped across arrays, which enables access to multiple arrays simultaneously.

Using RAID level 10, rather than a simple RAID set, up to 8 spans can be supported, and up to 8 drive failures can be tolerated, though less than total disk drive capacity is available. Though multiple drive failures can be tolerated, only one drive failure can be tolerated in each RAID 1 level array.

Figure 2.5 RAID 10 Logical Drive

RAID 10

Segment 1 Segment 1

Segment 5

...

Duplicate

Segment 5

Duplicate

RAID 1 RAID 1 RAID 1 RAID 1

RAID Levels 2-17

Segment 2 Segment 3

Segment 6

... ... ...

Segment 2 Duplicate

Segment 6 Duplicate

Segment 3 Segment 4

Segment 7

RAID 0

Duplicate

Segment 7

Duplicate

Segment 8

Segment 4

Duplicate

Segment 8

Duplicate

2.5.2.5 RAID 50

RAID 50 provides the features of both RAID 0 and RAID 5. RAID 50 includes both distributed parity and disk striping across multiple arrays. RAID 50 is best implemented on two RAID 5 disk arrays with data striped across both disk arrays.

RAID 50 breaks up data into smaller blocks, then stripes the blocks of data to each RAID 5 disk set. RAID 5 breaks up data into smaller blocks, calculates parity by performing an exclusive-or on the blocks, then writes the blocks of data and parity to each drive in the array. The size of each block is determined by the stripe size parameter, which is set during the creation of the RAID set.

RAID 50 can support up to 8 spans and tolerate up to 8 drive failures, though less than total disk drive capacity is available. Though multiple drive failures can be tolerated, only one drive failure can be tolerated in each RAID 1 level array.

Table 2.9 provides an overview of RAID 50.

Table 2.9 RAID 50 Overview

Feature Description Uses Appropriate when used with data that requires high

Strong Points Provides high data throughput, data redundancy and very

Weak Points Requires 2 to 8 times as many parity drives as RAID 5. Drives 6 to (14 drives x the number of channels)

Figure 2.6 provides an example of a RAID 50 level logical drive.

2-18 Introduction to RAID

reliability, high request rates, high data transfer, and medium to large capacity.

good performance.

Figure 2.6 RAID 50 Logical Drive

RAID 50

Segment 1 Segment 6

(Segment 9, 10)

Segment 2

(Segment 5, 6)

Segment 9

RAID 5 RAID 5

(Segment 1, 2)

Segment 5

Segment 10

(Segment 11, 12)

RAID 0

2.6 RAID Conﬁguration Strategies

The most important factors in RAID array conﬁguration are:

• Logical drive availability (fault tolerance)

• Logical drive performance

• Logical drive capacity

You cannot conﬁgure a logical drive that optimizes all three factors, but it is easy to choose a logical drive conﬁguration that maximizes one factor at the expense of another factor. For example, RAID 1 (mirroring) provides excellent fault tolerance, but requires a redundant drive. The following subsections describe how to use the RAID levels to maximize logical drive availability (fault tolerance), logical drive performance, and logical drive capacity.

Segment 3 Segment 8

Segment 4

(Segment 7, 8)

Segment 11

(Segment 3, 4)

Segment 7

Segment 12

2.6.1 Maximizing Fault Tolerance

Fault tolerance is achieved through the ability to perform automatic and transparent rebuilds using hot spare drives and hot swaps. A hot spare drive is an available, unused online drive that the RAID controller instantly plugs into the system when an active drive fails. After the hot spare is automatically moved into the RAID array, the failed drive is automatically rebuilt on the spare drive. The RAID array continues to handle requests while the rebuild occurs.

RAID Conﬁguration Strategies 2-19

A hot swap is the manual substitution of a replacement unit in a disk subsystem for a defective one, where the substitution can be performed while the subsystem is running hot swap drives. Auto-Rebuild in the BIOS Conﬁguration Utility allows a failed drive to be replaced and automatically rebuilt by hot-swapping the drive in the same drive bay. The RAID array continues to handle requests while the rebuild occurs, providing a high degree of fault tolerance and zero downtime. Table 2.10 describes the fault tolerance features of each RAID level.

Table 2.10 RAID Levels and Fault Tolerance

RAID Level Fault Tolerance

0 Does not provide fault tolerance. All data lost if any drive fails. Disk striping writes data across

1 Provides complete data redundancy. If one disk drive fails, the contents of the other disk drive

5 Combines distributed parity with disk striping. Parity provides redundancy for one drive failure

10 Provides complete data redundancy using striping across spanned RAID 1 arrays. RAID 10

50 Provides data redundancy using distributed parity across spanned RAID 5 arrays. RAID 50

multiple disk drives instead of just one disk drive. It involves partitioning each drive storage space into stripes that can vary in size. RAID 0 is ideal for applications that require high bandwidth but do not require fault tolerance.

can run the system and reconstruct the failed drive. The primary advantage of disk mirroring is that it provides 100% data redundancy.Since the contents of the disk drive are completely written to a second drive, no data is lost if one of the drives fails. Both drives contain the same data at all times. RAID 1 is ideal for any application that requires fault tolerance and minimal capacity.

without duplicating the contents of entire disk drives. If a drive fails, the RAID controller uses the parity data to rebuild all missing information. In RAID 5, this method is applied to entire drives or stripes across all disk drives in an array. Using distributed parity, RAID 5 offers fault tolerance with limited overhead.

works well for any environment that requires the 100 percent redundancy offered by mirrored arrays. RAID 10 can sustain a drive failure in each mirrored array and maintain drive integrity.

includes both parity and disk striping across multiple drives. If a drive fails, the RAID controller uses the parity data to recreate all missing information. RAID 50 can sustain one drive failure per RAID 5 array and still maintain data integrity.

2-20 Introduction to RAID

2.6.2 Maximizing Performance

A RAID disk subsystem improves I/O performance. The RAID array appears to the host computer as a single storage unit or as multiple logical units. I/O is faster because drives can be accessed simultaneously.

Table 2.11 describes the performance for each RAID level.

Table 2.11 RAID Levels and Performance

RAID Level Performance

0 RAID 0 (disk striping) offers the best performance of any RAID level. RAID 0 breaks up data

1 With RAID 1 (disk mirroring), each drive in the system must be duplicated, which requires

5 RAID 5 (distributed parity) provides high data throughput, especially for large ﬁles. Use this

10 RAID 10 (disk spanning) works best for data storage that needs the enhanced I/O

50 RAID 50 (disk spanning) works best when used with data that requires high reliability, high

into smaller blocks, then writes a block to each drive in the array. Disk striping writes data across multiple disk drives instead of just one disk drive. It involves partitioning each drive storage space into stripes that can vary in size from 8 Kbytes to 128 Kbytes. These stripes are interleaved in a repeated sequential manner. Disk striping enhances performance because multiple drives are accessed simultaneously.

more time and resources than striping. Performance is impaired during drive rebuilds.

RAID level for any application that requires high read request rates, but low write request rates, such as transaction processing applications, because each drive can read and write independently. Since each drive contains both data and parity, numerous writes can take place concurrently. In addition, robust caching algorithms and hardware based exclusive-or assist make RAID 5 performance exceptional in many different environments.

Parity generation can slow the write process, making write performance signiﬁcantly lower for RAID 5 than for RAID 0 or RAID 1. Disk drive performance is reduced if a drive is being rebuilt. Clustering can also reduce drive performance. Environments with few processes do not perform as well because the RAID overhead is not offset by the performance gains in handling simultaneous processes.

performance of RAID 0 (striped arrays), which provides high data transfer rates. Spanning increases the size of the logical volume and improves performance by doubling the number of spindles. The system performance improves as the number of spans increases. (The maximum number of spans is eight.) As the storage space in the spans is ﬁlled, the system stripes data over fewer and fewer spans and RAID performance degrades to that of a RAID 1 or RAID 5 array.

request rates, and high data transfer. It provides high data throughput, data redundancy, and very good performance. Spanning increases the size of the logical volume and improves performance by doubling the number of spindles. The system performance improves as the number of spans increases. (The maximum number of spans is eight.) As the storage space in the spans is ﬁlled, the system stripes data over fewer and fewer spans and RAID performance degrades to that of a RAID 1 or RAID 5 array.

RAID Conﬁguration Strategies 2-21

2.6.3 Maximizing Storage Capacity

Storage capacity is an important factor when selecting a RAID level. There are several variables to consider. Mirrored data and parity data require more storage space than striping alone (RAID 0). Parity generation uses algorithms to create redundancy and requires less space than mirroring. Table 2.12 explains the effects of the RAID levels on storage capacity.

Table 2.12 RAID Levels and Capacity

RAID Level Capacity

0 RAID 0 (disk striping) involves partitioning each drive storage space into stripes that can vary

1 With RAID 1 (disk mirroring), data written to one disk drive is simultaneously written to

5 RAID 5 (distributed parity) provides redundancy for one drive failure without duplicating the

10 RAID 10 (disk spanning) requires twice as many drives as all other RAID levels except RAID

50 RAID 50 (disk spanning) requires two to four times as many parity drives as RAID 5. This

in size. The combined storage space is composed of stripes from each drive.RAID 0 provides maximum storage capacity for a given set of physical disks.

another disk drive, which doubles the required data storage capacity. This is expensive because each drive in the system must be duplicated.

contents of entire disk drives. RAID 5 breaks up data into smaller blocks, calculates parity by performing an exclusive-or on the blocks, then writes the blocks of data and parity to each drive in the array. The size of each block is determined by the stripe size parameter, which is set during the creation of the RAID set.

1. RAID 10 works well for medium-sized databases or any environment that requires a higher degree of fault tolerance and moderate to medium capacity. Disk spanning allows multiple disk drives to function like one big drive. Spanning overcomes lack of disk space and simpliﬁes storage management by combining existing resources or adding relatively inexpensive resources.

RAID level works best when used with data that requires medium to large capacity.

2-22 Introduction to RAID

2.7 RAID Availability

Data availability without downtime is essential for many types of data processing and storage systems. Businesses want to avoid the ﬁnancial costs and customer frustration associated with downed servers. RAID helps you maintain data availability and avoid downtime for the servers that provide that data. RAID offers several features, such as spare drives and rebuilds, that you can use to ﬁx any hard drive problems, while keeping the server(s) running and data available. The following subsections describe these features.

2.7.1 Spare Drives

You can use spare drives to replace failed or defective drives in an array. A replacement drive must be at least as large as the drive it replaces. Spare drives include hot swaps, hot spares, and cold swaps.

A hot swap is the manual substitution of a replacement unit in a disk subsystem for a defective one, where the substitution can be performed while the subsystem is running (performing its normal functions). The backplane and enclosure must support hot swap in order for the functionality to work.

Hot spare drives are physical drives that power up along with the RAID drives and operate in a standby state. If a hard drive used in a RAID logical drive fails, a hot spare automatically takes its place and the data on the failed drive is rebuilt on the hot spare. Hot spares can be used for RAID levels 1, 5, 10, and 50.

A cold swap requires that you power down the system before replacing a defective hard drive in a disk subsystem.

2.7.2 Rebuilding

If a hard drive fails in an array that is conﬁgured as a RAID 1, 5, 10, or 50 logical drive, you can recover the lost data by rebuilding the drive. If you have conﬁgured hot spares, the RAID controller automatically tries

RAID Availability 2-23

Note: If a rebuild to a hot spare fails for any reason, the hot spare

drive is marked as failed. If the source drive fails, both the source drive and the hot spare drive are marked as failed.

to use them to rebuild failed disks. Manual rebuild is necessary if no hot spares with enough capacity to rebuild the failed drives are available.You must insert a drive with enough storage into the subsystem before rebuilding the failed drive.

2.8 RAID Conﬁguration Planning

Factors to consider when planning a conﬁguration are the number of hard disk drives the RAID controller can support, the purpose of the array, and the availability of spare drives.

Each type of data stored in the disk subsystem has a different frequency of read and write activity. If you know the data access requirements, you can more successfully determine a strategy for optimizing the disk subsystem capacity, availability, and performance.

Servers that support video on demand typically read the data often, but write data infrequently. Both the read and write operations tend to be long. Data stored on a general-purpose ﬁle server involves relatively short read and write operations with relatively small ﬁles.

2.8.1 Number of Physical Disk Drives

Your conﬁguration planning depends in part on the number of physical disk drives that you want to use in a RAID array. The number of drives in an array determines the RAID levels that can be supported. Only one RAID level can be assigned to each logical drive. Table 2.13 shows the minimum and maximum number of drives required for each RAID level.

Table 2.13 Physical Drives Required for Each RAID Level

RAID Level

0 1 14 28 1 2 2 2 5 3 14 28 10 4 14 28 50 6 14 28

2-24 Introduction to RAID

Minimum # of

Physical Drives

Maximum # of Physical Drives

for Single-Channel Controller

Maximum # of Physical Drives

for Dual-Channel Controller

2.8.2 Array Purpose

Important factors to consider when creating RAID arrays include availability, performance, and capacity. Deﬁne the major purpose of the disk array by answering questions related to these factors, such as the following,which are followed by suggested RAID levels for each situation:

• Does this disk array increase the system storage capacity for

general-purpose ﬁle and print servers? Use RAID 5, 10, or 50.

• Does this disk array support any software system that must be

available 24 hours per day? Use RAID 1, 5, 10, or 50.

• Does the information stored in this disk array contain large audio or

video ﬁles that must be available on demand? Use RAID 0.

• Does this disk array contain data from an imaging system? Use

RAID 0 or 10.

Fill out Table 2.14 to help you plan the array conﬁguration. Rank the requirements for your array, such as storage space and data redundancy, in order of importance, then review the suggested RAID levels.

Table 2.14 Factors to Consider for Array Conﬁguration

Requirement Rank Suggested RAID Level(s)

Storage space RAID 0, RAID 5 Data redundancy RAID 5, RAID 10, RAID 50 Hard drive performance and throughput RAID 0, RAID 10 Hot spares (extra hard drives required) RAID 1, RAID 5, RAID 10, RAID 50

RAID Conﬁguration Planning 2-25

2-26 Introduction to RAID

Chapter 3 BIOS Conﬁguration Utility and MegaRAID Manager

The MegaRAID BIOS Conﬁguration Utility (CU) conﬁgures disk arrays and logical drives. Because the CU resides in the BIOS, it is independent of the operating system.

MegaRAID Manager is a character-based, non-GUI utility that changes policies, and parameters, and monitors RAID systems. MegaRAID Manager runs under the DOS, Red Hat Linux, and NetWare operating systems.

The BIOS Conﬁguration Utility and MegaRAID Manager use the same command structure to conﬁgure controllers and disks. The following sections describe the steps to start either utility and detailed instructions to perform conﬁguration steps using either utility.

Note: MegaRAID Manager screens differ slightly from the BIOS

Conﬁguration Utility screens, but the utilities have similar functions.

Use the conﬁguration utilities to do the following:

• Select a conﬁguration method for physical arrays and logical disks

• Create physical arrays

• Deﬁne logical drives

• Initialize logical drives

• Access controllers, logical drives, and physical arrays to display their

properties

• Create hot spare drives

• Verify that the redundancy data in logical drives using RAID level

1, 5, 10, or 50 is correct

• Rebuild failed drives

MegaRAID Conﬁguration Software User’s Guide 3-1

• Reconstruct logical drives after changing RAID levels or adding a

hard drive to an array

• Select a MegaRAID host adapter

This chapter consists of the following sections:

• Section 3.1, “Quick Conﬁguration Steps for the BIOS

Conﬁguration Utility”

• Section 3.2, “Quick Conﬁguration Steps for MegaRAID Manager”

• Section 3.3, “Conﬁguration Utility Menu”

• Section 3.4, “Detailed Conﬁguration Instructions”

• Section 3.5, “Deleting Logical Drives”

• Section 3.6, “Performing Drive Roaming”

• Section 3.7, “Performing Drive Migration”

• Section 3.8, “Rebuilding Failed Disks”

• Section 3.9, “FlexRAID Virtual Sizing,”

• Section 3.10, “Checking Data Consistency”

• Section 3.11, “Reconstructing Logical Drives”

• Section 3.12, “Replacing a Failed Controller Containing Data in

the TBBU”

• Section 3.13, “Using a Preloaded System Drive”

• Section 3.14, “Exiting MegaRAID Conﬁguration Utility”

3.1 Quick Configuration Steps for the BIOS Configuration Utility

This section provides quick installation steps for users who are familiar with the MegaRAID utilities and tools. Refer to Section 3.4, “Detailed

Conﬁguration Instructions,” on page 3-16 for detailed conﬁguration

instructions. To conﬁgure arrays and logical drives using the MegaRAID CU:

Step 1. Boot the system. Step 2. Start the MegaRAID CU by pressing CTRL+M.

3-2 BIOS Conﬁguration Utility and MegaRAID Manager

Note: If the conﬁguration utility does not display, go into BIOS

setup and disable Quick boot, Fast boot, Silent boot, Intel Rapid boot, and Quick POST, then reboot. If you are still unable to access the conﬁguration utility, check for a

system BIOS upgrade or use Megaconf.exe. Step 3. Select a conﬁguration method. Step 4. Designate hot spare disks (optional). Step 5. Create arrays using the available physical drives. Step 6. Deﬁne the logical drive(s) using the space in the arrays. Step 7. Initialize the new logical drive(s).

3.2 Quick Conﬁguration Steps for MegaRAID Manager

This section provides quick installation steps for users who are familiar with the MegaRAID utilities and tools. See Section 3.4.4, “Conﬁguring

Arrays and Logical Drives,” on page 3-18 for detailed conﬁguration

instructions. The steps to conﬁgure arrays and logical drives with the MegaRAID

CU are: Step 1. Boot the system to DOS, Red Hat Linux, or NetWare.

Step 2. Start the MegaRAID Manager. Step 3. Select a conﬁguration method. Step 4. Designate hot spares (optional). Step 5. Create arrays using the available physical drives. Step 6. Deﬁne the logical drive(s) using the space in the arrays. Step 7. Initialize the logical drives.

Quick Conﬁguration Steps for MegaRAID Manager 3-3

3.3 Conﬁguration Utility Menu

Figure 3.1 shows the menu tree for the BIOS Conﬁguration Utility and

MegaRAID Manager. The following sections describe each menu item.

Figure 3.1 MegaRAID Conﬁguration Utility Menu Tree

Conﬁgure

(Section 3.3.1)

Initialize Objects

(Section 3.3.3)

(Section 3.3.2)

Clear

(Section 3.3.4) Rebuild Check Consistency Reconstruct Select Adapter

(Section 3.3.5)

Easy Conﬁguration New Conﬁguration View/Add Conﬁguration Clear Conﬁguration Specify Boot Drive

Adapter

Logical Drive

Physical Drive

Channel Battery Information Reset Battery

(Section 3.3.6)

(Section 3.3.7)

(Section 3.3.8)

Clear Conﬁguration FlexRAID PowerFail Fast Initialization Disk Spin Up Timings Cache Flush Timings Rebuild Rate Other Adapter Information Factory Default Disable BIOS Emulation Auto Rebuild Initiator ID Boot Time BIOS Options Patrol ReadOptions

Patrol Read Mode Patrol Read Status Patrol Read Control

Initialize

Check Consistency

View/Update Parameters Rebuild

Clear

Force Online Force Ofﬂine/Remove HSP

Make Hot Spare View Drive Information View Rebuild Progress SCSI Command Qtagging Transfer Speed Option

Channels

Charge Counter

Backup Module

Battery Pack Temperature Voltage Fast Charging No of Cycles

BIOS Stops on Error BIOS Echoes Message BIOS Conﬁguration Autoselection

RAID Size StripeSize Write Policy Read Policy Cache Policy #Stripes Drive State

Termination State SCSI Transfer Rate

3-4 BIOS Conﬁguration Utility and MegaRAID Manager

3.3.1 Conﬁgure Menu

Select this option to conﬁgure physical arrays and logical drives. This section describes the options of the Conﬁgure menu.

Conﬁguration Menu Options – The Conﬁgure menu provides four methods to modify and/or create logical disk conﬁguration: Easy Conﬁguration, New Conﬁguration, View/Add Conﬁguration, and Clear Conﬁguration. Table 3.1 provides an overview of these methods. The conﬁguration menu has an Advance Menu that enables you to set speciﬁc options. The available options depend upon the conﬁguration method you use.

To store the conﬁguration information, the CU reserves 32 bytes on a disk when a hard drive is conﬁgured.

Table 3.1 Conﬁguration Utility Conﬁgure Menu

Option Description

Easy Conﬁguration

New Conﬁguration

View/Add Conﬁguration

Clear Conﬁguration

Specify Boot Drive

Easy Conﬁguration automatically associates every physical array with one logical drive. Through the Advance Menu, Easy Conﬁguration allows you to modify the RAID level, stripe size, cache write policy, read policy, and I/O policy. Section 3.4.7.2, “Easy

Conﬁguration,” on page 3-22 provides detailed instructions.

New Conﬁguration allows you to modify the RAID level, stripe size, cache write policy, read policy, I/O policy, logical drive size, and array spanning (associating logical drives with multiple arrays). If you select New Conﬁguration, the CU deletes the existing conﬁguration information on the selected controller when saving the new conﬁguration.

Section 3.4.7.3, “New Conﬁguration and View/Add Conﬁguration,” on page 3-24

provides detailed instructions. View/Add Configuration allows you to control the same logical drive parameters as

New Configuration without disturbing the existing configuration information. The View/Add configuration also allows you to enable the Configuration on Disk feature.Section 3.4.7.3,

“New Configuration and View/Add Configuration,” provides detailed instructions.

This option erases the current conﬁguration information.

This option enables you to specify a logical drive as the boot drive on the adapter. This displays if you have created logical drives.

Conﬁguration Utility Menu 3-5

3.3.2 Initialize Option

This option initializes one or more logical drives, which prepares them for use. Initialize each new logical drive you configure. Section 3.4.8,

“Initializing Logical Drives,” on page 3-26 describes how to initialize drives.

Warning: Initializing a logical drive destroys all data on the logical drive.

3.3.3 Objects Menu

Select Objects from the Conﬁguration Utility main menu to view or change settings for the controller, logical drives, physical drives, and channels. Table 3.2 lists and describes the Objects menu options.

Table 3.2 Conﬁguration Utility Objects Menu

Menu Item Description

Adapter Use this option to conﬁgure the adapter properties. Section 3.3.3.1, “Adapter

Logical Drive Use this option to perform tasks on the logical drives. Section 3.3.3.4, “Logical

Physical Drive Use this option to perform tasks on the physical drives. Section 3.3.3.5, “Physical

Channel Use this option to conﬁgure channel-related or port-related properties.

Battery Information

Reset Battery Charge Counter

1. If the battery is not present on the board, this option does not display.

Submenu Description,” on page 3-6 provides more information.

Drive Submenu Description,” on page 3-10 provides more information.

Drive Submenu Description,” on page 3-12 provides more information.

Section 3.3.3.6, “Channel Submenu Description,” on page 3-13 provides

more information. Use this option to display and conﬁgure the battery backup on your system, if your

system supports the battery backup feature. Section 3.3.3.7, “Battery Backup

Submenu Description,” on page 3-14 provides more information.

Use this option to reset the battery charge counter.

3.3.3.1 Adapter Submenu Description

The Adapter submenu allows you to select a MegaRAID controller if your computer has multiple controllers. In addition, this submenu allows you to modify the parameters for the selected controller. Select Adapter from the Objects menu to select a controller and modify its parameters.

Table 3.3 provides Adapter submenu options.

3-6 BIOS Conﬁguration Utility and MegaRAID Manager

Table 3.3 Conﬁguration Utility Adapter Submenu

Option Description

Clear Conﬁguration This option erases the current RAID conﬁguration in the NVRAM. FlexRAID PowerFail Use this option to enable the FlexRAID®PowerFail feature, which allows drive

Fast Initialization Use this option to initialize the logical drive by writing zeros to the ﬁrst sector of

Disk Spin up Timings Use this option to conﬁgure the timing for spinning up the hard disk drives. The

Cache Flush Timings Use this option to set the cache ﬂush interval to 2, 4, 6, 8, or 10 seconds. Rebuild Rate Use this option to change the drive rebuild rate. The rebuild rate is the

Other Adapter Information

Factory Default Use this option to load the default MegaRAID Conﬁguration Utility settings. Disable BIOS Use this option to disable the BIOS. Emulation Use this option to select the I2C or mass storage mode. The default is mass

Auto Rebuild Use this option to enable automatic drive rebuilds after a drive failure. The failed

Initiator ID Use this option to set the initiator ID for the adapter. The default is 7. Boot Time BIOS

Options

reconstruction to continue when the system restarts after a power failure.

the logical drive. The fast initialization completes in 3 seconds. When this option is set to Disabled, a full initialization takes place on the entire

logical drive. On a larger array (over ﬁve drives), LSI recommends setting fast initialization to Disabled, then initializing. Otherwise, the controller runs a background consistency check within 5 minutes of reboot or RAID 5 creation.

options are Automatic, 2 disks every 6 secs, 4 disks every 6 secs, and 6 disks every 6 secs.

percentage of system resources dedicated to rebuilding a failed drive. A rebuild rate of 100 percent means the system is totally dedicated to rebuilding the failed drive. The default is 30 percent.

Use this option to display general information about the adapter, such as the adapter type, ﬁrmware version, BIOS version, and DRAM size.

storage mode.

drive is rebuilt with data from another drive or drives.

The following are options you can select for events that occur during bootup, such as BIOS error or messages.

• BIOS Stops on Error: Select this option to have the system BIOS stop during bootup if there are BIOS errors. This gives you the option to enter the conﬁguration utility to resolve the problem.

• BIOS Echoes Messages: When set to On (the default), all controller BIOS messages display during bootup.

• BIOS Conﬁguration Autoselection: Use this option if there is a mismatch between conﬁguration data in the hard disk drives and NVRAM, so you can select a method to resolve it. The options are Disk and User. The default is User.

Conﬁguration Utility Menu 3-7

Table 3.3 Conﬁguration Utility Adapter Submenu (Cont.)

Option Description

Patrol Read Options The Patrol Read function is designed as a preventive measure that includes

review of your system for possible physical disk errors that could lead to physical disk failure and damage data integrity. The Patrol Read operation can ﬁnd and possibly resolve any potential problem with physical disks prior to host access. This can enhance overall system performance because error recovery during a normal I/O operation may not be necessary.

• Patrol Read Mode: The Patrol Read mode can be set to Auto or Manual mode. In Auto mode, Patrol Read runs continuously on the system and is scheduled to start a new Patrol Read within four hours after the last iteration is completed.

• Patrol Read Status: Displays the number of iterations completed, the current state of the patrol read (active or stopped), and the schedule for the next execution of patrol read.

• Patrol Read Control: If you use Manual mode, select Patrol Read Control to initiate a Patrol Read. Press ENTER, then select Start and press ENTER again.

3.3.3.2 Port Multiplier

The port multiplier is a mechanism that connects a MegaRAID SATA controller to up to four hard drives per port. This allows you to connect more devices, driving down the cost per port. For example, with the SATA 300-8X Controller, which has eight ports, you can connect up to 32 devices using eight, 1-to-4 port multipliers.

In the BIOS Conﬁguration Utility, the default for the Port Multiplier option is Disabled. You can access this option and select Enabled in order to use the port multipliers. When you enable the Port Multiplier option, it becomes effective after you reboot. When you reboot, the BIOS banner displays either PM-ENBL or PM-DSBL to indicate whether the Port Multiplier option is enabled or disabled.

You can change the setting for this option only if no logical drives are conﬁgured. If you attempt to change the setting and if there are any logical drives present, a message displays to state that this is not allowed, as shown in Figure 3.2.

3-8 BIOS Conﬁguration Utility and MegaRAID Manager

Figure 3.2 Port Multiplier Option

The BIOS Conﬁguration Utility displays the port and physical drive information in a matrix format. This format displays the port number and ID numbers for the hard drives connected to each port. This format is used for logical drive conﬁguration, physical drive conﬁguration, rebuilds, and reconstructions. Figure 3.3 displays port and drive information in this format.

Figure 3.3 Port and Drive Information

Conﬁguration Utility Menu 3-9

3.3.3.3 Enclosure Management

MegaRAID SATA 300 RAID controllers offer enclosure management through the same protocols used for SCSI Accessed Fault-Tolerant Enclosures (SAF-TE), using an I2C interface to communicate with the storage enclosure processor (SEP). This feature allows you to use RAID capabilities provided by the SATA 300 adapters in an enclosure containing your hard drives.

The SATA 300 controllers uses the SAF-TE command protocol to communicate control and status with the SEP. The SAF-TE protocol, deﬁned in the SATA II speciﬁcation, communicates or performs SAF-TE operations such as setting the drive state and turning the LED on or off with the SEP device. SEP is a microcontroller that resides on a SATA backplane. It senses drive insertion status, driveactivity,and status LEDs for each hard drive slot. The drive status is reported and LED control performed according to commands through the I located on the backplane near each hard drive slot.

3.3.3.4 Logical Drive Submenu Description

Select this option from the Conﬁguration Utility Objects menu to select a logical drive and to perform the actions in Table 3.4.

C bus. LEDs are

Table 3.4 Conﬁguration Utility Logical Drive Submenu

Option Description

Initialize Use this option to initialize the selected logical drive. Initialize every logical drive that

Check Consistency

View/Update Parameters

3-10 BIOS Conﬁguration Utility and MegaRAID Manager

you conﬁgure. Use this option to verify the correctness of the redundancy data in the selected logical

drive and have the CU automatically correct any differences found in the data. This option is available if you are using RAID level 1, 5, 10, or 50.

Use this option to display the properties of the selected logical drive. This option allows you to modify the cache write policy, read policy, and the I/O policy.

Refer to Section 3.9, “FlexRAID Virtual Sizing,” on page 3-32 for more information on virtual sizing.

You can access the Advanced Menu from the View/Update Parameters option.

The View/Update Parameters submenu is accessible through the View/Update Parameters option in the Logical Drive submenu. Table 3.5 describes the Advance submenu.

Table 3.5 Conﬁguration Utility View/Update Parameters Submenu

Option Description

RAID Use this option to indicate the RAID level for the array. The number of physical drives

in a speciﬁc array determines the RAID levels that can be implemented with the array. Size Use this option to indicate the size of the logical drive in Mbytes. Stripe Size Use this option to specify the size of the segments written to each drive in a RAID 1,

5, 10, or 50 conﬁguration. The default stripe size is 64 Kbytes. You can set the stripe

size to 8, 16, 32, 64, or 128 Kbytes.

A larger stripe size improves read performance, especially if your system performs

mostly sequential reads. However, if you are sure that your computer does random

read requests more often, select a small stripe size.

Write Policy

Use this option to set the caching method to write-through or write-back. The default

setting is write-through caching. In write-through caching, the controller sends a data

transfer completion signal to the host after the disk subsystem receives all the data in

a transaction.

In write-back caching, the controller sends a data transfer completion signal to the

host after the controller cache receives all the data in a transaction.

Write-through caching has a data security advantage over write-back caching, while

write-back caching has a performance advantage. Read Policy Use this option to enable the read-ahead cache feature for the logical drive. You can

set this parameter to Normal, Read-Ahead, or Adaptive. The default setting is Normal.

Normal caching speciﬁes that the controller reads only the requested data and does

not read ahead for the current logical drive.

Read-Ahead caching speciﬁes that the controller uses read-ahead caching for the

current logical drive. Read-Ahead caching allows the controller to read sequentially

ahead of requested data and to store the additional data in cache memory,

anticipating that the data is needed soon. Read-Ahead supplies sequential data faster,

but is not as effective when accessing random data.

Adaptive speciﬁes that the controller begins using Read-Ahead caching if the two

most recent disk accesses occurred in sequential sectors. If all read requests are

random, the algorithm reverts to Normal; however, all requests are still evaluated for

possible sequential operation.

Conﬁguration Utility Menu 3-11

Table 3.5 Conﬁguration Utility View/Update Parameters Submenu (Cont.)

Option Description

Cache Policy Use this option to enable read buffering in cache memory. Cache Policy applies to

#Stripes Indicates the number of data segments striped across hard drives in a logical drive. Drive State Indicates the drive state of a logical drive. The states are OPTIMAL, DEGRADED, and

1. The adapter must have a battery backup unit to support write-back caching.

reads on a speciﬁc logical drive. It does not affect the Read-Ahead cache. The default

setting is Direct I/O.

Cached I/O speciﬁes that the controller buffers all reads in cache memory.

Direct I/O speciﬁes that the controller does not buffer reads in cache memory. Data

is transferred to cache and the host concurrently. If the same data block is read again,

it comes from cache memory.

OFFLINE.

3.3.3.5 Physical Drive Submenu Description

Select this option from the Objects menu to select a physical drive and to perform the operations listed in Table 3.6.

3-12 BIOS Conﬁguration Utility and MegaRAID Manager

Table 3.6 Conﬁguration Utility Physical Drive Submenu

Option Description

Rebuild Use this option to rebuild a failed physical drive that is part of a redundant

Clear Use this option to clear the data from SCSI disk drives. This is for SCSI

Force Online Use this option to change the state of the selected disk drive to Online. Force Ofﬂine/

Remove HSP Make Hot Spare Use this option to designate the selected disk drive as a hot spare. A hot

View Drive Information Use this option to display the drive properties for the selected physical

View Rebuild Progress Use this option to enable synchronous negotiation with a physical device.

View Rebuild Progress Use this option to view the progress of the physical drive rebuild. SCSI Command

Qtagging

Transfer Speed Option Use this option to set the data transfer speed.

array. Data from a good drive or drives rebuilds the failed drive.

drives only.

Use this option to change the state of the selected disk drive to Fail.

spare is an idle, powered-on standby drive ready for use if another drive fails. When a drive fails, the controller ﬁrmware automatically rebuilds the data on the hot spare from a redundant drive or drives. Data can be rebuilt only from logical drives with redundancy (RAID 1, 5, 10, and 50, not RAID 0). The hot spare must be at least as large as the failed drive it is replacing.

device, such as device type, capacity, vendor ID, and device errors.

This is available only for SCSI controllers.

Use this option to set the number of queue tags per command to Disabled, 2, 3, 4, or Enhanced. The default setting is Enhanced. This option is available for SCSI controllers only.

3.3.3.6 Channel Submenu Description

Select this option from the Conﬁguration Utility Objects menu to choose a channel or port on the controller. Table 3.7 lists and describes the Channel submenu options.

Table 3.7 Conﬁguration Utility Channel Submenu

Option Description

Termination State Use this option to control termination on the MegaRAID SCSI controller. The

SCSI Transfer Rate This option enables the user to set the SCSI transfer rate as Fast, Ultra, Ultra2,

MegaRAID SCSI controller sets this option automatically, though you can set it manually.

Ultra160, or Ultra320 SCSI.

Conﬁguration Utility Menu 3-13

3.3.3.7 Battery Backup Submenu Description

Select this option from the Conﬁguration Utility Objects menu to display information about the battery backup. Table 3.8 lists and describes the options for the Battery Backup submenu. This option is available only on controllers that support the battery back-up feature.

Note: If the battery is not present on the board, the battery

options do not display.

Table 3.8 Conﬁguration Utility Battery Backup Submenu

Option Description

Backup Module Indicates whether the battery module is present. Battery Pack Indicates whether the battery module is correctly installed. Temperature Indicates whether the temperature is within the normal operating range. Voltage Indicates whether the voltage is within the normal operating range. Fast Charging Indicates whether the battery pack is charging, or if the fast charge cycle is complete. No of Cycles Indicates the number of charge cycles that the battery pack has undergone. The

battery pack life is 1100 charge cycles. You must replace the battery pack after it reaches this limit.

3.3.4 Clear Option

Select the Clear option from the Conﬁguration Utility Management Menu to clear data on one or more physical drives.

You do not have to select Clear to erase existing information on your disks, such as a system partition. Initialization of the logical drives erases all the information on the drive.

3.3.5 Rebuild Option

Select this option to rebuild failed disk drives. If a disk drive fails that is in a RAID 1, 5, 10, or 50 configuration, you can recover the lost data by rebuilding the drive. The CU can perform an automatic rebuild if hot spare disks are available in the system. If no hot spare disks are available, the data must be manually rebuilt. Refer to Section 3.8, “Rebuilding Failed

Disks,” on page 3-30 for the procedure on rebuilding disks.

3-14 BIOS Conﬁguration Utility and MegaRAID Manager

3.3.6 Check Consistency Option

Select this option to verify the redundancy data in logical drives that use RAID levels 1, 5, 10, or 50. When you select Check Consistency, the system displays the parameters of the existing logical drives on the current controller and a selection menu that lists the logical drives by number. The CU automatically corrects any discrepancies with the assumption that the data is correct and that the error exists in the parity information. However, if the failure is a read error on a data drive, the bad data block is reassigned with the generated data. See Section 3.10, “Checking Data

Consistency,” on page 3-32 for the Check Consistency procedure.

3.3.7 Reconstruct Option

Select this option to perform a reconstruction. A reconstruction occurs when you change the RAID level of an array or add a physical drive to an existing array. Refer to Section 3.11, “Reconstructing Logical Drives,”

on page 3-33 for the procedure to perform a reconstruction.

3.3.8 Select Adapter Menu

This menu item appears only if the system contains more than one MegaRAID host adapter. The CU lists the adapters present in the system after you choose the Select Adapter option. Select the MegaRAID adapter that you want to conﬁgure from this menu.

Conﬁguration Utility Menu 3-15

3.4 Detailed Conﬁguration Instructions

This section provides detailed instructions for conﬁguring the logical disks and arrays in a MegaRAID system. MegaRAID provides several hot keys that you can use during the conﬁguration process. Table 3.9 summarizes the hot key deﬁnitions.

Table 3.9 Conﬁguration Hot Keys

Key Function

F2 Use this option to display the manufacturer data and error count for the

selected drive. F3 Use this option to display the conﬁgured logical drives. F4 Use this option to designate the selected drive as a hot spare. F10 Use this option to display the logical drive configuration screen. The option

is available only when using New Configuration or View/Add Configuration.

3.4.1 Starting the MegaRAID Conﬁguration Utility

While the host computer boots, hold the CTRL key and press the M key when a BIOS banner such as the following appears:

Press <Ctrl><M> to run MegaRAID BIOS Configuration Utility

This causes the CU start-up window to appear. For each MegaRAID adapter in the host system, the CU displays the ﬁrmware version, the DRAM size, and the status of logical drives on the adapter. If you do not press CTRL+M within a few seconds of the prompt, the system continues the normal boot procedure.

Note: You can access multiple controllers through the BIOS

Conﬁguration Utility. Be sure to verify which controller you are currently set to edit.

3.4.2 Resolving a Conﬁguration Mismatch

A conﬁguration mismatch happens when the conﬁguration data in the NVRAM and that on the hard disk drives are different. In case of a conﬁguration mismatch, the following message displays during the power-on self-test (POST): Unresolved configuration mismatch between disk(s) and NVRAM on the adapter.

3-16 BIOS Conﬁguration Utility and MegaRAID Manager

You need to update the conﬁguration data in either the NVRAM or on the hard disk drive. Perform the following steps to resolve the mismatch.

Step 1. Press CTRL+M when prompted during bootup to access the

BIOS Conﬁguration Utility.

Step 2. Select Conﬁgure → View/Add Conﬁguration.

This gives you the option to view both the conﬁguration on the

NVRAM and the hard drive disk. Step 3. Select either NVRAM or conﬁguration on disk. Step 4. Press ESC and select YES to update the conﬁguration data. Step 5. Press ESC to exit, then reboot.

3.4.3 Starting MegaRAID Manager

MegaRAID Manager runs under the following operating systems:

• MS-DOS

• NetWare

• Red Hat Linux

Note: For more information about these operating systems and

driver installation, refer to the MegaRAID Device Driver

Installation User’s Guide. To start MegaRAID Manager, ensure the program ﬁle is in your ﬁle path. In DOS, type:

MegaConf

In NetWare, type:

load megamgr

For any other operating system (OS), refer to the documentation that accompanied the OS.

Detailed Conﬁguration Instructions 3-17

3.4.4 Conﬁguring Arrays and Logical Drives

The following procedures apply to both the BIOS Conﬁguration Utility and MegaRAID Manager.

Step 1. Designate hot spares (optional).

See Section 3.4.6, “Designating Drives as Hot Spares” in this section for more information.

Step 2. Select a conﬁguration method.

See Section 3.4.7, “Creating Physical Arrays and Logical

Drives” in this section for more information.

Step 3. Create arrays using the available physical drives. Step 4. Deﬁne logical drives using the arrays. Step 5. Save the conﬁguration information. Step 6. Initialize the logical drives.

See Section 3.4.8, “Initializing Logical Drives” in this section for

more information.

3.4.5 Selecting a Conﬁguration Method

The Conﬁgure Menu has options for Easy Conﬁguration, New Conﬁguration, View/Add Conﬁguration, or Clear Conﬁguration.

Section 3.4.7, “Creating Physical Arrays and Logical Drives,” provides

detailed instructions for using each conﬁguration method.

Caution: When you use the New Conﬁguration option to create a

conﬁguration, the existing conﬁguration data is erased.

3.4.6 Designating Drives as Hot Spares

The hot spare has to be at least as large as the hard drive that it replaces. Only global hot spares can be assigned; dedicated hot spares cannot be assigned.

3-18 BIOS Conﬁguration Utility and MegaRAID Manager

There are two methods for designating physical drives as hot spares:

• Pressing F4 while creating arrays in Easy, New or View/Add

Conﬁguration mode.

• Using the Objects → Physical Drive menu.

F4 Key –

When you select any conﬁguration option, a list of all physical devices connected to the current controller appears. Perform the following steps to designate a drive as a hot spare:

Step 1. On the Management Menu select Conﬁgure, then a

conﬁguration option. Step 2. Press the arrow keys to highlight a hard drive that displays as

READY. Step 3. Press F4 to designate the drive as a hot spare. Step 4. Click YES to make the hot spare.

The drive displays as HOTSP. Step 5. Save the conﬁguration.

Objects Menu –

Step 1. On the Management Menu select Objects → Physical Drive.

A physical drive selection screen appears. Step 2. Select a hard drive in the READY state and press ENTER to

display the action menu for the drive. Step 3. Press the arrow keys to select Make Hot spare and press

ENTER.

The selected drive displays as HOTSP.

3.4.7 Creating Physical Arrays and Logical Drives

This subsection provides instructions for using the Easy Conﬁguration, New Conﬁguration, and View/Add Conﬁguration. LSI recommends using drives with the same capacity in a speciﬁc array. If you use drives with different capacities in an array, the CU treats all these drives as if they have the capacity of the smallest drive.

Detailed Conﬁguration Instructions 3-19

The number of physical drives in a speciﬁc array determines the RAID levels that you can implement with the array. RAID 0 requires one or more physical drives. RAID 1 requires exactly two physical drives. RAID 5 requires at least three physical drives.

Note: The ﬁrmware does not support creation of logical drives

greater than 2 Tbytes.

3.4.7.1 Logical Drive Parameters

The following paragraphs describe the parameters that you can set for the logical drives, which include the RAID level, stripe size, read policy, write policy, cache policy, and spanning mode.

After you create an array or arrays, you can select the parameters for the logical drive. Table 3.10 contains descriptions of the parameters.

3-20 BIOS Conﬁguration Utility and MegaRAID Manager

Table 3.10 Logical Drive Parameters and Descriptions

Parameter Description

RAID Level The number of physical drives in a speciﬁc array determines the RAID levels that can

be implemented with the array.

Stripe Size The stripe size parameter speciﬁes the size of the segments written to each disk in

a RAID 1, 5, 10, or 50 conﬁguration. You can set the stripe size as 8, 16, 32, 64, or 128 Kbytes. The default is 64 Kbytes.

A larger stripe size produces higher read performance, especially if your computer does mostly sequential reads. If your computer regularly performs random read requests, select a smaller stripe size.

Write Policy Write Policy speciﬁes the cache write parameter. You can set the write policy to

Write-back or Write-through. In Write-back caching, the controller sends a data transfer completion signal to the

host when the controller cache has received all the data in a transaction. LSI recommends using this setting in standard mode.

Note: If Write-back is enabled and the system is quickly turned off and on,

the RAID controller may hang when ﬂushing cache memory. Controllers that contain a battery backup default to Write-back caching.

In Write-through caching, the controller sends a data transfer completion signal to the host when the disk subsystem has received all the data in a transaction.

Write-through caching has a data security advantage over write-back caching, while write-back caching has a performance advantage.

Note: Enabling clustering turns off write cache. The MegaRAID 320-2

controller supports clustering.

Read Policy The read parameter determines the type of read option for the logical drive. You can

set this parameter to Normal, Read-ahead, or Adaptive. The default setting is Normal. The options are

• Normal speciﬁes that the controller reads only the requested data and does not read ahead for the current logical drive.

• Read-ahead speciﬁes that the controller uses read-ahead for the current logical drive. Read-ahead capability allows the adapter to read sequentially ahead of requested data and store the additional data in cache memory, anticipating that the data is needed soon. Read-ahead supplies sequential data faster, but is not as effective when accessing random data.

• Adaptive speciﬁes that the controller begins using read-ahead if the two most recent disk accesses occurred in sequential sectors. If all read requests are random, the algorithm reverts to Normal; however, all requests are still evaluated for possible sequential operation.

Detailed Conﬁguration Instructions 3-21

Table 3.10 Logical Drive Parameters and Descriptions (Cont.)

Parameter Description

Cache Policy Use this option to enable read buffering in cache memory. Cache Policy applies to

Span The RAID controller supports spanning of RAID 1 and 5 arrays. You can span two or

reads on a speciﬁc logical drive. It does not affect the Read-ahead cache. The default setting is Direct I/O.

• Cached I/O speciﬁes that the controller buffers reads in cache memory.

• Direct I/O specifies that reads and writes are not buffered in cache memory. Direct

I/O does not override the read policy settings. Data is transferred to cache and the host concurrently. If the same data block is read again, it comes from cache memory.

more RAID 1 arrays into a RAID 10 array and two or more RAID 5 arrays into a RAID 50 array. The maximum number of drives that you can span is eight. For two arrays to be spanned, they must have the same stripe width (they must contain the same number of physical drives).

The options are: Yes – Array spanning is enabled for the current logical drive. The logical drive can occupy space in more than one array. No – Array spanning is disabled for the current logical drive. The logical drive can occupy space in only one array.

3.4.7.2 Easy Conﬁguration

In Easy Conﬁguration, the CU associates each hard drive with a single logical drive. If logical drives have already been conﬁgured, the CU does not change their conﬁguration. Perform the following steps to create arrays using Easy Conﬁguration.

Step 1. Select Conﬁgure → Easy Conﬁguration from the MegaRAID

CU Main menu.

The Management Menu array selection menu appears. Step 2. Press the arrow keys to select speciﬁc physical drives. Step 3. Press the spacebar to associate the selected physical drive

with the current array.

After you associate a physical drive with a current array, the

indicator forthe drive changes from READY to ONLIN A[array

number]-[drive number]. For example, ONLIN A2-3

indicates array 2 with disk drive 3. Step 4. Press ENTER after you ﬁnish creating the current array.

3-22 BIOS Conﬁguration Utility and MegaRAID Manager

The logical drive conﬁguration screen appears. It displays the

logical drive number, RAID level, logical drive size, the number

of stripes in the physical array, the stripe size, and the state of

the logical drive.

Note: The ﬁrmware does not support creation of logical drives

greater than 2 Tbytes.

Step 5. Highlight RAID and press ENTER to set the RAID level for the

logical drive.

The CU displays the available RAID levels for the current

logical drive. Step 6. Select a RAID level and press ENTER. Step 7. Click Advanced Menu to open the menu for logical drive settings. Step 8. Set the Stripe Size. Step 9. Set the Write Policy. Step 10. Set the Read Policy. Step 11. Set the Cache Policy. Step 12. Press ESC to exit the Advanced Menu. Step 13. After you deﬁne the current logical drive, select Accept and

press ENTER.

The array selection screen appears if any disk drives remain

unconﬁgured. Step 14. Repeat these steps to conﬁgure additional logical drives,

if desired.

MegaRAID supports up to 40 logical drives per controller. Step 15. If you are through conﬁguring logical drives, press ESC to exit

Easy Conﬁguration. Step 16. Save the conﬁguration when prompted. Step 17. Initialize the logical drives.

Refer to Section 3.4.8, “Initializing Logical Drives,” on page 3-26

for detailed instructions.

Detailed Conﬁguration Instructions 3-23

3.4.7.3 New Conﬁguration and View/Add Conﬁguration

New Configuration and View/Add Configuration associate logical drives with partial and/or multiple physical arrays. New Configuration deletes the existing configuration and replaces it with the configuration that you specify. View/Add Configuration lets you view or modify an existing configuration.

Caution: The New Conﬁguration option erases the existing

conﬁguration data when you save the new array conﬁguration.

Perform the following steps to conﬁgure a disk array using New Conﬁguration or View/Add Conﬁguration.

Step 1. Select Conﬁgure → New Conﬁguration or Conﬁgure →

View/Add Conﬁguration from the Management Menu.

The CU displays an array selection window. Step 2. Use the arrow keys to select speciﬁc physical drives to include

in the array. Step 3. Press the spacebar to associate the selected physical drive

with the current array.

The indicator for the selected drive changes from READY to

ONLIN A[array number]-[drive number]. For example,

ONLIN A2-3 means disk drive 3 in array 2.

Step 4. Press ENTER after you create the current array. Step 5. Press F10 to conﬁgure logical drives. Step 6. Highlight RAID and press ENTER to set the RAID level for the

logical drive.

The CU displays the available RAID levels for the current

logical drive. Step 7. Select a RAID level and press ENTER.

If you have two RAID 1 or RAID 5 arrays, the spanning mode

is set automatically for RAID 10 and RAID 50. Step 8. Move the cursor to Size and press ENTER to set the logical

drive size.

3-24 BIOS Conﬁguration Utility and MegaRAID Manager

By default, the logical drive size associates the available space

in the array(s) with the current logical drive, accounting for the

Span setting and partially-used array space. Step 9. Highlight Span and press ENTER.

Table 3.11 describes the spanning mode options.

Table 3.11 Spanning Mode Options

Spanning Option Description

CanSpan This option enables array spanning for the current logical

NoSpan This option disables array spanning for the current logical

drive. The logical drive can occupy space in more than one array.

drive. The logical drive can occupy space in only one array.

For two arraysto be spannable, they must have the same stripe

width and must be consecutively numbered. For example, if

Array 2 contains four disk drives, you can span it only with

Array 1 and/or Array 3, and only if Arrays 1 and 3 each contain

four disk drives. If the criteria are not met, the CU ignores the

span setting for the current logical drive. Step 10. Select Advanced Menu to open the menu for logical

drive settings. Step 11. Set the Stripe Size by pressing ENTER and selecting a value. Step 12. Set the Write Policy. Step 13. Set the Read Policy. Step 14. Set the Cache Policy. Step 15. Press ESC to exit the Advanced Menu. Step 16. After you deﬁne the current logical drive, select Accept and

press ENTER.

If space remains in the arrays, the next logical drive to be

conﬁgured appears. If the array space has been used, a list of

the existing logical drives appears. Step 17. Press any key to continue, then respond to the Save prompt.

Detailed Conﬁguration Instructions 3-25

Step 18. Initialize the logical drives you just conﬁgured.

Section 3.4.8, “Initializing Logical Drives,” on page 3-26

provides detailed instructions.

3.4.8 Initializing Logical Drives

You can initialize the logical drives individually or in batches. Individual initialization initializes a single logical disk. Batch initialization initializes up to 40 logical drives simultaneously.

Note: If there are ﬁve or more drives in a RAID 5 array,

background batch initialization starts automatically.

Batch Initialization – Perform the following step to initialize logical drives.

Step 1. Select Initialize from the Management Menu.

A list of the current logical drives appears. Step 2. Press the spacebar to select the desired logical drive for

initialization.

Optionally, you can press F2 to select or deselect all

logical drives. Step 3. After you ﬁnish selecting logical drives, press F10 and select

Yes at the conﬁrmation prompt.

The CU displays a bar graph showing the initialization progress. Step 4. When initialization is complete, press any key to continue or

press ESC to display the Management Menu.

Individual Initialization –

Step 1. Select Objects → Logical Drive from the Management Menu. Step 2. Select the logical drive to be initialized. Step 3. Select Initialize from the action menu.

Initialization progress appears as a bar graph on the screen. Step 4. When initialization completes, press any key to display the

previous menu.

3-26 BIOS Conﬁguration Utility and MegaRAID Manager

3.5 Deleting Logical Drives

This RAID controller supports the ability to delete any unwanted logical drives and use that space for a new logical drive. You can have an array with multiple logical drives and delete a logical drive without deleting the whole array.

After you delete a logical drive, you can create a new one. You can use the conﬁguration utilities to create the next logical drive from the noncontiguous free space (holes), and from the newly created arrays. The conﬁguration utility provides a list of conﬁgurable arrays where there is a space to conﬁgure.

Note: The deletion of the logical drive can fail under certain

conditions: During a rebuild, initialization or check consistency of a logical drive, if that drive has a higher

logical drive number than the drive you want to delete. Perform the following steps to delete logical drives: Step 1. Select Objects → Logical Drive from the Management Menu.

The logical drives display.

Step 2. Use the arrow key to highlight the logical drive you want to

delete.

Step 3. Press F5 to delete the logical drive.

This deletes the logical drive and makes the space it occupied available for you to make another logical drive.

3.6 Performing Drive Roaming

Drive roaming occurs when the hard drives are changed to different channels or different target IDs on the same controller. When the drives are placed on different channels, the controller detects the RAID conﬁguration from the conﬁguration data on the drives.

Deleting Logical Drives 3-27

Conﬁguration data is saved in both nonvolatile random access memory (NVRAM) on the RAID controller and on the hard drives attached to the controller. This maintains the integrity of the data on each drive, even if the drives have changed their target ID.

Note: In a clustering environment, drive roaming is supported

within the same channel only. Drive roaming between

channels in a cluster is not supported.

Note: Driveroaming from multiple controllers to a cluster-configured

controller is not supported. Perform the following steps to use drive roaming: Step 1. Turn off all power to the system and all hard drives, enclosures,

and system components, then disconnect power cords from the system.

Step 2. Open the host system by following the instructions in the host

system technical documentation.

Step 3. Remove the unshielded, twisted pair, SCSI ribbon cable

connectors from the internal drives or the shielded cables from the external drives you want to move.

- Make sure pin 1 on the cable matches pin 1 on the connector.

- Make sure that the SCSI cables conform to all SCSI

speciﬁcations. Step 4. Connect the hard drives to different connectors on the cable. Step 5. Determine the SCSI ID and SCSI termination requirements.

Note: Thedefault for SCSI termination is onboard SCSI termination

enabled. See the MegaRAID 320 Storage Adapters User’s Guide for more information about SCSI termination.

Step 6. Perform a safety check.

◊ Make sure all cables are properly attached. ◊ Make sure the RAID controller is properly installed. ◊ Close the cabinet of the host system. ◊ Turn power on after completing the safety check.

Step 7. Power on the system.

The controller then detects the RAID conﬁguration from the

conﬁguration data on the drives.

3-28 BIOS Conﬁguration Utility and MegaRAID Manager

3.7 Performing Drive Migration

Drive migration is the transfer of a set of hard drives in an existing conﬁguration from one controller to another. If you put the hard drives on a new controller, the controller must have a clear conﬁguration. To keep the original conﬁguration, the drives must remain on the same channel and be reinstalled in the same order as were on the previous controller.

Note: Drive roaming and drive migration cannot be supported at

the same time. The MegaRAID controller can support either drive roaming or drive migration, but not both at the same time.

The drives must remain on the same channel and be reinstalled in the same order as in the original conﬁguration. You can perform online RAID level migration when you do this. In addition, no reboot is necessary after capacity expansion.

Perform the following steps to migrate drives: Step 1. Turn off all power to the system and all hard drives, enclosures,

and system components, then disconnect power cords from the

systems. Step 2. Open the host systems by following the instructions in the host

system technical documentation. Step 3. Remove the unshielded, twisted pair, SCSI ribbon cable

connectors from the internal drives or the shielded cables from

the external drives you want to migrate.

◊ Make sure pin 1 on the cable matches pin 1 on the connector. ◊ Make sure that the SCSI cables conform to all SCSI

speciﬁcations.

Step 4. Remove the hard drives from the ﬁrst system and insert them

into drive bays on the second. Step 5. Connect the SCSI cables to the hard drives in the second system. Step 6. Determine the SCSI ID and SCSI termination requirements.

Performing Drive Migration 3-29

Note: Thedefault for SCSI termination is onboard SCSI termination

enabled. See the MegaRAID 320 Storage Adapters User’s Guide for more information of SCSI termination.

Step 7. Perform a safety check.

◊ Make sure all cables are properly attached. ◊ Make sure the RAID controller is properly installed. ◊ Close the cabinet of the host system. ◊ Turn power on after completing the safety check.

Step 8. Power on the system.

The controller then detects the RAID conﬁguration from the

conﬁguration data on the drives.

3.8 Rebuilding Failed Disks

If hot spare disks are present in the system, the MegaRAID controller automatically uses them to rebuild failed disks.

3.8.1 Rebuild Types

Table 3.12 describes automatic and manual rebuilds.

Table 3.12 Rebuild Types

Type Description

Automatic Rebuild

Manual Rebuild

3-30 BIOS Conﬁguration Utility and MegaRAID Manager

If you have conﬁgured hot spares, the RAID controller automatically tries to use them to rebuild failed disks. Select Objects → Physical Drive to display the list of physical drives while a rebuild is in progress. The hot spare drive changes to REBLD A[array number][drive number], indicating the hard drive is being replaced by the hot spare. For example, REBLD A01-02 indicates that the data is being rebuilt in array 1 on hard drive 2.

Manual rebuild is necessary if no hot spares with enough capacity to rebuild the failed drives are available.You must insert a drive with enough storage into the subsystem before rebuilding the failed drive.

The CU allows manual rebuild for an individual drive or a group of drives. Rebuilding a group of drives is done through the batch mode. Use the following procedures to rebuild a failed drive manually in individual or batch mode.

3.8.2 Manual Rebuild – Rebuilding an Individual Drive

To perform a batch rebuild on an individual drive, follow these steps: Step 1. Select Objects → Physical Drive from the Management Menu.

A device selection window displays the devices connected to

the current controller. Step 2. Designate an available drive as a hot spare before the

rebuild starts.

See Section 3.4.6, “Designating Drives as Hot Spares” for

instructions on designating a hot spare. Step 3. Press the arrow keys to select the failed physical drive you want

to rebuild, then press ENTER. Step 4. Select Rebuild from the action menu and respond to the

conﬁrmation prompt.

Rebuilding can take some time, depending on the drive capacity. Step 5. When the rebuild is complete, press any key to display the

previous menu.

3.8.3 Manual Rebuild – Rebuilding in Batch Mode

To perform a batch rebuild on a group of drives, follow these steps: Step 1. Select Rebuild from the MegaRAID Conﬁguration Utility main

menu. The CU displays a device selection window that marks

the failed drives with FAIL indicators. Step 2. Press the arrow keys to select all drives to be rebuilt. Press the

spacebar to select the chosen physical drive for rebuild. Step 3. After selecting the physical drives, press F10, and select Yes at

the conﬁrmation prompt. The indicators for the selected drives

change to REBLD. Step 4. When rebuild is complete, press any key to continue. Press

ESC to display the main menu.

Rebuilding Failed Disks 3-31

3.9 FlexRAID Virtual Sizing

The FlexRAID Virtual Sizing option can no longer be enabled on the MegaRAID 320-1 or 320-2 controllers. This option allowed the Windows NT and NetWare 5.1 operating systems to use the new space of a RAID array immediately after you added capacity online or performed a reconstruction.

If you have this option enabled on older cards, you need to disable it, then upgrade the ﬁrmware. Perform the following steps to do this:

Step 1. Go to the www.lsilogic.com web site. Step 2. Download the latest ﬁrmware and driver to a diskette or directly

to your system.

The download is an executable ﬁle. Step 3. Unzip the ﬁle and extract it to a blank diskette. Step 4. Boot with a DOS diskette to the DOS prompt. Step 5. Insert the diskette with the extracted ﬁles and type mflash to

ﬂash the ﬁrmware.

3.10 Checking Data Consistency

Select this option to verify the data redundancy in logical drives that use RAID levels 1, 5, 10, and 50. (RAID 0 does not provide data redundancy.) The parameters of the existing logical drives appear. Discrepancies are automatically corrected when the data is correct. However, if the failure is a read error on a data drive, the bad data block is reassigned and the data is regenerated.

Important: LSI recommends that you run periodic data consistency

checks on a redundant array. This allows detection and automatic replacement of bad blocks. Finding a bad block during a rebuild of a failed drive is a serious problem, as the system does not have the redundancy to recover the data.

3-32 BIOS Conﬁguration Utility and MegaRAID Manager

Perform the following steps to run Check Consistency. Step 1. Select Check Consistency from the Management Menu.

Step 2. Press the arrow keys to highlight the desired logical drives. Step 3. Press the spacebar to select or deselect a drive for consistency

checking. Step 4. Press F2 to select or deselect all the logical drives. Step 5. Press F10 to begin the consistency check.

A progress graph for each selected logical drive displays. Step 6. When the check is ﬁnished, press any key to clear the

progress display. Step 7. Press ESC to display the Management Menu.

(To check an individual drive, select Objects → Logical Drives from the Management Menu, the desired logical drive(s), then Check Consistency on the action menu.)

3.11 Reconstructing Logical Drives

A reconstruction occurs when you change the RAID level of an array or add a physical drive to an existing array. Perform the following steps to reconstruct a logical drive:

Step 1. Move the arrow key to highlight Reconstruct on the

Management Menu. Step 2. Press ENTER.

The window entitled Reconstructables displays. This contains

the logical drives that can be reconstructed. You can press F2

to view logical drive information or ENTER to select the

reconstruct option. Step 3. Press ENTER.

The next reconstruction window displays. The options on this

window are the spacebar to select a drive, ENTER to open the

reconstruct menu, and F3 to display logical drive information.

Reconstructing Logical Drives 3-33

Step 4. Press ENTER to open the reconstruct menu.

The menu items are RAID level, stripe size, and reconstruct. Step 5. To change the RAID level, select RAID with the arrow key, and

press ENTER. Step 6. Select Reconstruct and press ENTER to reconstruct the

logical drive.

Note: After you start the reconstruct process, you must wait until

it is complete. You cannot reboot, cancel, or exit until the reconstruction is complete.

3.12 Replacing a Failed Controller Containing Data in the TBBU

The MegaRAID Transportable Battery Backup Module (TBBU) is a cache memory module with an integrated battery pack. The module provides an uninterrupted power source to the module if power is unexpectedly interrupted while there is still cached data present. If the power failure is the result of the MegaRAID controller itself failing, then the TBBU can be moved to a new controller and the data recovered. The replacement controller must have a cleared conﬁguration.

Perform the following steps to replace a failed controller with data in the transportable battery backup unit.

Step 1. Power-down the system and drives. Step 2. Remove the failed controller from the system. Step 3. Remove the TBBU from the failed controller. Step 4. Insert the TBBU into the replacement controller. Step 5. Insert the replacement controller into the system. Step 6. Power-on the system.

The controller then reads the disk conﬁguration into NVRAM and ﬂush cache data to the logical drives.

3-34 BIOS Conﬁguration Utility and MegaRAID Manager

Resolving a Conﬁguration Mismatch in a Replacement Controller –

When you move a TBBU from the failed controller to a replacement controller, a conﬁguration mismatch occurs if the replacement controller has a previous conﬁguration. A conﬁguration mismatch happens when the conﬁguration data in the NVRAM and that on the hard disk drives are different.

In case of a conﬁguration mismatch, the following message displays during the power-on self-test (POST): Unresolved configuration mismatch between disk(s) and NVRAM on the adapter.

In this situation, you need to update the conﬁguration data in the NVRAM with the data from the hard disk drive. Perform the following steps to resolve the mismatch.

Step 1. Press CTRL+M when prompted during bootup to access the

BIOS Conﬁguration Utility.

Step 2. Select Conﬁgure → View/Add Conﬁguration.

This gives you the option to view both the conﬁguration on the

NVRAM and the hard drive disk. Step 3. Select the conﬁguration on disk. Step 4. Press ESC and select YES to update the NVRAM. Step 5. Press ESC to exit, then reboot.

3.13 Using a Preloaded System Drive

Note: Deﬁne a preloaded system drive as the ﬁrst logical drive. If

the drive is not a boot device, the logical drive number is not critical.

You can use the MegaRAID controller as the adapter for this drive by performing the following steps:

Step 1. Connect the drive to the channel or port on the MegaRAID

controller. Step 2. Boot the computer, then start the Conﬁguration Utility. Step 3. Select Easy Conﬁguration from the Conﬁgure menu.

Using a Preloaded System Drive 3-35

Step 4. Press the cursor keys to select the preloaded drive. Step 5. Press the spacebar.

The preloaded drive now becomes an array element. Step 6. Press ENTER. The preloaded drive is a one-disk array. Step 7. Display the logical drive conﬁguration screen. Step 8. Set the read policy and cache option on the Advanced menu. Step 9. Press ESC to exit the Advanced menu, then highlight Accept

and press ENTER. Step 10. Press ESC and select Yes at the Save prompt. Step 11. Exit Conﬁguration Utility and reboot. Step 12. Set the host system to boot from the drive.

3.14 Exiting MegaRAID Conﬁguration Utility

Press ESC when the MegaRAID Conﬁguration Utility management menu is displayed to exit MegaRAID Conﬁguration Utility.

3-36 BIOS Conﬁguration Utility and MegaRAID Manager

Chapter 4 WebBIOS Conﬁguration Utility

This chapter describes the WebBIOS Conﬁguration Utility and consists of the following sections:

• Section 4.1, “General Description”

• Section 4.2, “Quick Conﬁguration Steps”

• Section 4.3, “Starting the WebBIOS Conﬁguration Utility on the

Host Computer”

• Section 4.4, “Screen and Option Descriptions”

• Section 4.5, “Conﬁguring RAID Arrays and Logical Drives”

4.1 General Description

The WebBIOS Conﬁguration Utility (CU) provides a Web-based utility to conﬁgure and manage RAID volumes. The utility conﬁgures disk arrays and logical drives. Its operation is independent of the operating system because the utility resides in the MegaRAID BIOS.

The WebBIOS CU performs the following actions:

• Displays adapter properties

• Scans devices

• Creates physical arrays

• Deﬁnes logical drives

• Displays logical drive properties

• Initializes logical drives

• Checks data for consistency

MegaRAID Conﬁguration Software User’s Guide 4-1

• Displays the physical properties of devices

• Allows capacity expansion and drive migration

The WebBIOS CU provides a conﬁguration wizard to guide you through the conﬁguration of logical drives and physical arrays.

4.2 Quick Conﬁguration Steps

This section provides the steps to conﬁgure arrays and logical drives using the WebBIOS CU. The following sections describe how to perform each action using the WebBIOS CU. The steps are:

Step 1. Power-on the system. Step 2. Start the WebBIOS CU by pressing CTRL+H. Step 3. Start the Conﬁguration Wizard. Step 4. Select a conﬁguration method. Step 5. Create arrays using the available physical drives. Step 6. Deﬁne the logical drive(s) using the space in the arrays. Step 7. Initialize the new logical drives.

4.3 Starting the WebBIOS Conﬁguration Utility on the Host Computer

While the host computer boots, hold down the CTRL key and press the H key when the following appears:

After you press CTRL+H, the Adapter Selection screen displays, as shown in Figure 4.1. This screen lists the adapters, adapter numbers, and ﬁrmware versions. Select an adapter and press the Start button to begin the conﬁguration.

4-2 WebBIOS Conﬁguration Utility

Note: If there is a conﬁguration mismatch between the disks and

the nonvolatile random access memory (NVRAM), the CU displays the Select Conﬁguration screen.

Figure 4.1 WebBIOS Adapter Selection Screen

Starting the WebBIOS Conﬁguration Utility on the Host Computer 4-3

4.4 Screen and Option Descriptions

This section describes the various WebBIOS screens and options.

4.4.1 WebBIOS Toolbar Options

Table 4.1 describes the WebBIOS toolbar icons.

Table 4.1 WebBIOS Toolbar Icon Descriptions

Icon Description

Click this icon to return to the main screen.

Click this icon to return to the page you accessed immediately before the current page.

Click this icon to exit the WebBIOS program.

Click this icon to display the adapters that you can select.

Click this icon to scan for devices connected to your system.

Click this icon to display the properties of the adapter, such as the ﬁrmware version, BIOS version, RAM size, and initiator ID.

Click the icon to access the Conﬁguration Wizard so that you can conﬁgure the arrays and logical drives.

Click this icon to turn off the sound on the alarm.

Click this icon to display the WebBIOS version, browser version, and HTML interface engine.

4-4 WebBIOS Conﬁguration Utility

4.4.2 Main Screen

When you press CTRL+H on the host computer, the WebBIOS CU displays the main screen.

Figure 4.2 WebBIOS Main Screen

From the main screen you can scan the devices connected to the controller, select a MegaRAID adapter if multiple adapters are in the system, alternate between the physical devices view and the logical devices view, and access other screens. The main screen provides the following options:

• Adapter Properties

• Scan Devices

• SCSI Channel Properties

• Logical Drives

• Physical Drives

• Conﬁguration Wizard

Screen and Option Descriptions 4-5

• Adapter Selection

• Physical View

• Exit

4.4.3 Adapter Properties Screen

The Adapter Properties screen, as Figure 4.3 shows, allows you to view and conﬁgure the software and hardware of the selected adapter. You access the Adapter Properties screen from the WebBIOS main screen.

Figure 4.3 WebBIOS Adapter Properties Screen

4-6 WebBIOS Conﬁguration Utility

Table 4.2 describes the Adapter Properties menu options.

Table 4.2 WebBIOS Adapter Properties Menu Options

Option Description

Firmware Version This option displays the ﬁrmware version number. BIOS Version This option displays the BIOS version number. Battery Backup This option indicates whether battery backup is present. If present, click

RAM Size This option displays the size of the random access memory (RAM). Cluster Mode Use this option to enable or disable cluster mode. The default is Disabled.

Initiator ID Identifying number for the MegaRAID card. The default is 7. You can

Rebuild Rate Use this option to select the rebuild rate for drives attached to the selected

FlexRAID PowerFail Use this option to enable the FlexRAID PowerFail feature, which allows drive

Alarm Control Use this option to enable, disable, or silence the onboard alarm tone

Adapter BIOS Use this option to enable the adapter BIOS. The default is Enabled. If the

Set Factory Defaults Use this option to load the default MegaRAID WebBIOS CU settings. The

ChkConst Restore When enabled, this option allows the ﬁrmware to ﬁx medium errors found

Present to display the following battery details: temperature, voltage, progress of charging, number of cycles, and reset option.

When this is disabled, the system operates in standard mode. A cluster is a grouping of independent servers that can access the same data storage and provide services to a common set of clients.

change the Initiator ID only when you are in cluster mode. You cannot change the ID while in standard mode. The ID can be a number from 0 to

15. We recommend that you use 6 or 7. When you are in standard mode, the ID is always 7.

adapter. The default is 30 percent. The rebuild rate is the percentage of system resources dedicated to rebuilding a failed drive. A rebuild rate of 100 percent means the system is totally dedicated to rebuilding a failed drive.

reconstruction, rebuild, or check consistency to continue when the system restarts after a power failure, reset, or hard boot. The default is Enabled.

generator. The default is Disabled.

boot device is on the RAID controller, the BIOS must be enabled; otherwise, the BIOS should be disabled or it might not be possible to use a boot

device elsewhere.

default is No.

during a data consistency check. The medium error is logged in the NVRAM. The default is Enabled.

Screen and Option Descriptions 4-7

Table 4.2 WebBIOS Adapter Properties Menu Options (Cont.)

Option Description

Force Boot Option Use this option to determine how the BIOS handles a conﬁguration

Bios Stops on Error When set to On, the BIOS stops in case of a problem with the conﬁguration.

BIOS Echoes Messages When set to On (the default), all controller BIOS messages display during

Bios Conﬁg AutoSelection Use this option if there is a mismatch between conﬁguration data in the

Spinup Parameters Use this option to set the timing for spinning up the hard disk drives in the

Fast Initialization When enabled, zeros are written to the ﬁrst sector of the logical drive so

mismatch. A conﬁguration mismatch occurs when the conﬁguration data on the NVRAM and that on the hard drives are different.

If you set the Force Boot Option to On, then when a conﬁguration mismatch occurs, the BIOS reads the conﬁguration data that exists on the hard drive, writes it on NVRAM, and reboots the system. The options are On and Off. The default is On.

This gives you the option to enter the conﬁguration utility to resolve the problem. The default is On.

bootup.

drives and NVRAM, so you can select a method to resolve it. The options are NVRAM, Disk, and User. The default is User.

computer. The options are Automatic, 2 per 6 sec, 4 per 6 sec, or 6 per 6 sec. The default is 2 per 6 sec.

that initialization occurs in 2 to 3 seconds. The options are Enabled and Disabled. The default is Enabled.

When disabled, a full initialization takes place on the entire logical drive. On a larger logical drive, LSI recommends disabling fast initialization, then initializing. Otherwise, the controller runs a background consistency check within 5 minutes of reboot or RAID 5 creation.

PCI Delay Trans Use this option to enable PCI delay transfers, which improve performance

on some older system boards. The choices are Enabled and Disabled. The default is Enabled.

Auto Rebuild Use this option to automatically rebuild drives when they fail. The options

are Enabled and Disabled. The default is Enabled.

Class Emulation Mode Use this option to select I

mode. The default is Mass Storage. This option allows the ﬁrmware to

use I

O drivers or regular drivers.

O or Mass Storage as the class emulation

Temporary RAID Ofﬂine Use this option to allow the ﬁrmware to bring all the drives in an array back

online, except for the ﬁrst failed drive. The default is Disabled. Enabling this option gives you access to the array. If disabled, you cannot access the array if there are two or more failed drives in the array.

4-8 WebBIOS Conﬁguration Utility

4.4.4 Scan Devices Option

When you select the Scan Devices option on the main screen, WebBIOS checks the physical and logical drives for any changes of the drive status. WebBIOS displays the results of the scan in the physical and logical drive descriptions.

4.4.5 SCSI Channel Properties

The SCSI Channel Properties option displays the following information about the selected SCSI channel (bus):

• Channel Width (number of bits)

• Termination (enabled or disabled)

• SCSI Capabilities (data transfer speed)

4.4.6 Logical Drive Screen

You can access the Logical Drive screen, as shows in Figure 4.4,by clicking a logical drive in the logical drive list on the main screen. The Logical Drive screen provides options to:

• Set logical drive policies (read, write, I/O, virtual sizing)

• Initialize the logical drives

• Check consistency

• Display the logical drive properties

• Remove a physical drive from an array

• Delete a logical drive

• Select drive migration only or drive migration with addition

You can press Go to perform the selected action or Reset to delete any changes.

Screen and Option Descriptions 4-9

Figure 4.4 WebBIOS Logical Drive Screen

4.4.6.1 Initialization

This option initializes the selected logical drive by writing zeroes to the entire volume (if fast initialization is selected, zeroes are written to the ﬁrst sector only).

Note: After you define a logical drive, WebBIOS asks you for

initialization of the logical drive. LSI does not recommended choosing to initialize, as a background initialization may run.

4.4.6.2 Check Consistency

This option veriﬁes that the redundancy data is correct and available for arrays using RAID 1, 5, 10, or 50. If a difference in the data is found, the MegaRAID adapter assumes that the data is accurate and automatically corrects the parity value.

4-10 WebBIOS Conﬁguration Utility

4.4.6.3 Logical Drive Deletion

This option deletes a logical drive. The RAID controller supports the ability to delete any unwanted logical drives and use that space for a new logical drive. The conﬁguration utility provides a list of conﬁgurable arrays where there is a space to conﬁgure. You can have an array with multiple logical drives and delete a logical drive without deleting the whole array.

Note: The deletion of the logical drive can fail under certain

4.4.6.4 Drive Migration

Drive migration is the transfer of a set of hard drives in an existing conﬁguration from one controller to another. If you put the hard drives on a new controller, the controller must have a clear conﬁguration. The drives must remain on the same channel and must be reinstalled in the same order as in the original conﬁguration.

In addition, the drives must be on the same channel/target as they were on the previous controller to keep the same conﬁguration.

conditions: During a rebuild, initialization or check consistency of a logical drive, if that drive has a higher logical drive number than the drive you want to delete.

Note: For more information and the procedure for drive migration,

refer to Section 3.7, “Performing Drive Migration,” page 3-29.

Screen and Option Descriptions 4-11

4.4.7 Physical Drive Screen

This screen, as Figure 4.5 shows, displays the physical drives for each channel or port. This screen displays the properties for the selected physical drive, including drive size, drive state, SCSI level,and drive health. You can use this screen to make hot spares and format a hard drive.

Figure 4.5 WebBIOS Physical Drive Screen

4-12 WebBIOS Conﬁguration Utility

4.4.8 Conﬁguration Mismatch Screen

A conﬁguration mismatch occurs when the conﬁguration data in the NVRAM and that on the hard drives are different. You can use the Conﬁguration Mismatch screen, as shown in Figure 4.6, to resolve the mismatch by doing one of the following:

• Select Create New Conﬁguration to delete the previous conﬁguration

and create a new conﬁguration

• Select View Disk Conﬁguration to restore the conﬁguration from the

hard drive

• Select View NVRAM Conﬁguration to restore the conﬁguration from

the NVRAM

Figure 4.6 WebBIOS Conﬁguration Mismatch Screen

Screen and Option Descriptions 4-13

4.4.9 Conﬁguration Wizard Option

This option enables you to clear a conﬁguration, create a new conﬁguration, or add a conﬁguration. Section 4.5, “Conﬁguring RAID

Arrays and Logical Drives,” provides detailed steps for using the

Conﬁguration Wizard.

4.4.10 Adapter Selection Option

When you select this option on the main screen, the conﬁguration utility displays a list of the MegaRAID adapters in the system. You can select an adapter and begin conﬁguration.

4.4.11 Physical View/Logical View Option

This option toggles between views of the physical drives and logical drives.

4.4.12 Exit

Use this option to exit the WebBIOS Conﬁguration Utility.

4.5 Conﬁguring RAID Arrays and Logical Drives

This section provides detailed steps for using the Conﬁguration Wizard to conﬁgure RAID arrays and logical drives. Figure 4.7 displays the ﬁrst screen for the Conﬁguration Wizard.

Step 1. Start the Conﬁguration Wizard by selecting the

Conﬁguration Wizard icon on the WebBIOS main screen. The ﬁrst screen offers the following options:

• Clear Conﬁguration, to clear the existing conﬁguration

• New Conﬁguration, which clears the existing conﬁguration (any data

in previously deﬁned conﬁguration is lost)

• Add Conﬁguration, which retains the old conﬁguration, then adds

new drives to it (this does not cause any data loss)

4-14 WebBIOS Conﬁguration Utility

Figure 4.7 WebBIOS Conﬁguration Wizard Screen

Step 2. Select the type of conﬁguration and press Next.

The next screen displays the conﬁguration methods. LSI recommends Configuration With Redundancy. You can select one of the following:

• Custom Configuration

• Auto Configuration With Redundancy

• Auto Configuration Without Redundancy. Auto

Step 3. Select a conﬁguration method and press Next.

The Array Definition screen displays. Use this screen to add ready drives to create an array.

Step 4. Hold the CTRL key while selecting ready drives on the

Physical Drives window, then click Accept Array to add the drives to the arrays shown in the Arrays window.

If you need to undo the changes, press the Reclaim button.

Conﬁguring RAID Arrays and Logical Drives 4-15

Step 5. After you create the arrays, click Next.

The Logical Drive Definition screen displays. You can use this screen to select the RAID level, stripe size, read policy, cache policy, spanning option, and logical drive size.

Step 6. Set the following options to deﬁne the logical drive:

a. Select the RAID level. The possible RAID levels for the logical drive display in the

drop-down menu. b. Select the stripe size.

Figure 4.8 WebBIOS Logical Drive Deﬁnition Screen

The stripe size parameter speciﬁes the size of the segment written to each disk in a RAID conﬁguration.

You can set the stripe size to 2, 4, 8, 16, 32, 64, or 128 Kbytes. A larger stripe size produces higher read performance. If your computer regularly performs random read requests, choose a smaller stripe size. The default is 64 Kbytes.

4-16 WebBIOS Conﬁguration Utility

Avago Technologies SATA 150-4 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Preface

Contents

1.1 MegaRAID Tool Description

1.2 Operating System Support

2.1 RAID Description

2.3 RAID Functions

2.4 RAID Components and Features

2.4.1 Physical Array

2.4.2 Logical Drive

2.4.3 RAID Array

2.4.4 Fault Tolerance

2.4.5 Consistency Check

2.4.6 Background Initialization

2.4.7 Patrol Read

2.4.8 Disk Striping

2.4.9 Disk Mirroring

2.4.10 Parity

2.4.11 Disk Spanning

2.4.12 Hot Spares

2.4.13 Disk Rebuilds

2.4.14 SCSI Physical Drive States

2.4.15 Logical Drive States

2.4.16 Enclosure Management

2.5 RAID Levels

2.5.1 Summary of RAID Levels

2.5.2 Selecting a RAID Level

2.6.1 Maximizing Fault Tolerance

2.6.2 Maximizing Performance

2.6.3 Maximizing Storage Capacity

2.7 RAID Availability

2.7.1 Spare Drives

2.7.2 Rebuilding

2.8.1 Number of Physical Disk Drives

2.8.2 Array Purpose

3.3.2 Initialize Option

3.3.3 Objects Menu

3.3.4 Clear Option

3.3.5 Rebuild Option

3.3.6 Check Consistency Option

3.3.7 Reconstruct Option

3.3.8 Select Adapter Menu

3.4.3 Starting MegaRAID Manager

3.4.6 Designating Drives as Hot Spares

3.4.7 Creating Physical Arrays and Logical Drives

3.4.8 Initializing Logical Drives

3.5 Deleting Logical Drives

3.6 Performing Drive Roaming

3.7 Performing Drive Migration

3.8 Rebuilding Failed Disks

3.8.1 Rebuild Types

3.8.2 Manual Rebuild – Rebuilding an Individual Drive

3.8.3 Manual Rebuild – Rebuilding in Batch Mode

3.9 FlexRAID Virtual Sizing

3.10 Checking Data Consistency

3.11 Reconstructing Logical Drives

3.13 Using a Preloaded System Drive

4.1 General Description

4.4 Screen and Option Descriptions

4.4.1 WebBIOS Toolbar Options

4.4.2 Main Screen

4.4.3 Adapter Properties Screen

4.4.4 Scan Devices Option

4.4.5 SCSI Channel Properties

4.4.6 Logical Drive Screen

4.4.7 Physical Drive Screen

4.4.10 Adapter Selection Option

4.4.11 Physical View/Logical View Option

4.4.12 Exit