Dell PERC 3 User Manual

Dell™ PowerEdge Expandable RAID Controller 3/QC, 3/DC, 3/DCL and
3/SC

PERC 3 User’s Guide

www.dell.com | support.dell.com

____________________

Information in this document is subject to change without notice.
© 2002 Dell Computer Corporation. All rights reserved.

Reproduction in any manner whatsoever without the written permission of Dell Computer
Corporation is s tr ictly forbid den.

Trademar ks used in th is text : Dell, the DELL logo, PowerEdge, PowerVault, and Dell OpenManage
are trademarks and DellWare is a registered service mark of Dell Computer Corporation. MegaRAID
is a registered trademark of LSI Logic Corporation. Microsoft, Windows NT, MS-DOS and Windows
are registered trademarks of Microsoft Corporation. Intel and Pentium are registered tra demark s of
Intel Corporation. Novell and NetWare are regi s tered trademar ks of Novel l Co rporation. ASPI is a
registered trademark of Adaptec, I nc. IBM is a registered trademark of International Business
Machines.

Other trademarks and trade names may be used in this document to refer to either the entities claiming
the marks and names or their products. Dell Computer Corporation disclaims any proprietary interest
in trademarks and trade names oth er tha n its own.

July 2002 P/N 5C229 Rev. A04

Safety Instructions

CAUTION: Safety Instructions

Use the following safety guidelines to help ensure your own personal safety
and to help protect your computer and working environment from potential
damage.

General

• Do not attempt to service the computer yourself unless you are a
trained service technician. Always follow installation instructions
closely.

• To help prevent electric shock, plug the computer and device power
cables into properly grounded electrical outlets. These cables are
equipped with 3-prong plugs to help ensure proper grounding. Do not
use adapter plugs or remove the grounding prong from a cable. If you
must use an extension cable, use a 3-wire cable with properly grounded
plugs.

• To help avoid the potential hazard of electric shock, do not use your
computer during an electrical storm.

• To help avoid the potential hazard of electric shock, do not connect or
disconnect any cables or perform maintenance or reconfiguration of
this product during an electrical storm.

• If your computer includes a modem, the cable used with the modem
should be manufactured with a minimum wire size of 26 American
wire gauge (AWG) and an FCC-compliant RJ-11 modular plug.

• Before you clean your computer, disconnect the computer from the
electrical outlet. Clean your computer with a soft cloth dampened
with water. Do not use liquid or aerosol cleaners, which may contain
flammable substances.

• To help avoid possible damage to the system board, wait 5 seconds
after turning off the computer before disconnecting a device from the
computer.

• To avoid shorting out your computer when disconnecting a network
cable, first unplug the cable from the network adapter on the back of
your computer, and then from the network jack. When reconnecting a
network cable to your computer, first plug the cable into the network
jack, and then into the network adapter.

1

• To help protect your computer from sudden, transient increases and
decreases in electrical power, use a surge suppressor, line conditioner,
or uninterruptible power supply (UPS).

• Ensure that nothing rests on your computer’s cables and that the
cables are not located where they can be stepped on or tripped over.

• Do not push any objects into the openings of your computer. Doing so
can cause fire or electric shock by shorting out interior components.

• Keep your computer away from radiators and heat sources. Also, do not
block cooling vents. Avoid placing loose papers underneath your
computer; do not place your computer in a closed-in wall unit or on a
bed, sofa, or rug.

www.dell.com | support.dell.com

When Using Your Computer

As you use your computer, observe the following safe-handling guidelines.

CAUTION: Do not operate your computer with any cover(s)

(including computer covers, bezels, filler brackets, front-panel
inserts, and so on) removed.

Your computer is equipped with one of the following:

• A fixed-voltage power supply — Computers with a fixed-voltage power
supply do not have a voltage selection switch on the back panel and
operate at only one voltage (see the regulatory label on the outside of
the computer for its operating voltage).

• An auto-sensing voltage circuit — Computers with an auto-sensing
voltage circuit do not have a voltage selection switch on the back panel
and automatically detect the correct operating voltage.

• A manual voltage selection switch — Computers with a voltage
selection switch on the back panel must be manually set to operate at
the correct operating voltage.

To help avoid damaging a computer with a manual voltage selection switch,
ensure that the voltage selection switch is set to match the AC power
available at your location:

• 115 V/60 Hz in most of North and South America and some Far
Eastern countries such as South Korea and Taiwan

2

• 100 V/50 Hz in eastern Japan and 100 V/60 Hz in western Japan

• 230 V/50 Hz in some regions in the Caribbean and South America and
most of Europe, the Middle East, and the Far East

Also, ensure that your monitor and attached devices are electrically rated to
operate with the AC power available in your location.

• Before working inside the computer, unplug the computer to help
prevent electric shock or system board damage. Certain system board
components continue to receive power any time the computer is
connected to AC power.

When Working Inside Your Computer

Before you open the computer cover, perform the following steps in the
sequence indicated.

CAUTION: Do not attempt to service the computer yourself,

except as explained in your online Dell™ documentation or in
instructions otherwise provided to you by Dell. Always follow
installation and service instructions closely.

NOTICE: To help avoid possible damage to the system board, wait 5 seconds

after turning off the computer before removing a component from the system
board or disconnecting a device from the computer.

1

Perform an orderly computer shutdown using the operating system
menu.

NOTE: The voltage

selection switch must be
set to the 115-V position
even though the AC power
available in Japan is
100 V.

2 Turn off your computer and any devices connected to the computer.

3 Ground yourself by touching an unpainted metal surface on the

chassis, such as the metal around the card-slot openings at the back of
the computer, before touching anything inside your computer.

While you work, periodically touch an unpainted metal surface on the
computer chassis to dissipate any static electricity that might harm
internal components.

4 Disconnect your computer and devices, including the monitor, from

their electrical outlets. Also, disconnect any telephone or
telecommunication lines from the computer.

Doing so reduces the potential for personal injury or shock.

In addition, take note of these safety guidelines when appropriate:

3

• When you disconnect a cable, pull on its connector or on its strain­relief loop, not on the cable itself. Some cables have a connector with
locking tabs; if you are disconnecting this type of cable, press in on the
locking tabs before disconnecting the cable. As you pull connectors
apart, keep them evenly aligned to avoid bending any connector pins.
Also, before you connect a cable, ensure that both connectors are
correctly oriented and aligned.

• Handle components and cards with care. Do not touch the
components or contacts on a card. Hold a card by its edges or by its
metal mounting bracket. Hold a component such as a microprocessor
chip by its edges, not by its pins.

www.dell.com | support.dell.com

CAUTION: There is a danger of a new battery exploding if it is

incorrectly installed. Replace the battery only with the same or
equivalent type recommended by the manufacturer. Do not
dispose of the battery along with household waste. Contact your
local waste disposal agency for the address of the nearest battery
deposit site.

Protecting Against Electrostatic Discharge

Static electricity can harm delicate components inside your computer. To
prevent static damage, discharge static electricity from your body before you
touch any of your computer’s electronic components, such as the
microprocessor. You can do so by touching an unpainted metal surface on
the computer chassis.

As you continue to work inside the computer, periodically touch an
unpainted metal surface to remove any static charge your body may have
accumulated.

You can also take the following steps to prevent damage from electrostatic
discharge (ESD):

• Do not remove components from their antistatic packing material
until you are ready to install the component in your computer. Just
before unwrapping the antistatic packaging, discharge static electricity
from your body.

• When transporting an electrostatic sensitive component, first place it
in an antistatic container or packaging.

• Handle all electrostatic sensitive components in a static-safe area. If
possible, use antistatic floor pads and workbench pads.

4

Ergonomic Computing Habits

CAUTION: Improper or prolonged keyboard use may result in

injury.

CAUTION: Viewing the monitor screen for extended periods of

time may result in eye strain.

Battery Disposal

Do not dispose of the battery along with household waste. Contact your
local waste disposal agency for the address of the nearest battery deposit
site.

5

www.dell.com | support.dell.com

6

Contents

Safety Instructions . . . . . . . . . . . . . . . . . . . . . . . . . 1

1 Overview

PERC 3 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 24

PERC 3 Features

SCSI Channels

. . . . . . . . . . . . . . . . . . . . . . . . . . 24

. . . . . . . . . . . . . . . . . . . . . . . . . 25

Non-volatile Random Access Memory (NVRAM) and Flash
Read-only Memory (ROM)

SCSI Connectors . . . . . . . . . . . . . . . . . . . . . . . . 25

Single-Ended and LVD SCSI Buses . . . . . . . . . . . . . . . 26

Maximum Cable Length for SCSI Standards

SCSI Bus Widths and Maximum Throughput . . . . . . . . . . 26

Operating System Support . . . . . . . . . . . . . . . . . . . 27

2 Introduction to RAID

RAID Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

PERC 3 Host-Based RAID Solution

Components and Features . . . . . . . . . . . . . . . . . . . . . 31

Physical Array

Logical Drive

Fault Tolerance

Consistency Check

Disk Striping

Disk Mirroring

Disk Spanning

Spanning for RAID 10 or RAID 50

. . . . . . . . . . . . . . . . . . . . . . . . . 31

. . . . . . . . . . . . . . . . . . . . . . . . . . 31

. . . . . . . . . . . . . . . . . . . . . . . . . 31

. . . . . . . . . . . . . . . . . . . . . . . . 32

. . . . . . . . . . . . . . . . . . . . . . . . . . 32

. . . . . . . . . . . . . . . . . . . . . . . . . 34

. . . . . . . . . . . . . . . . . . . . . . . . . 35

. . . . . . . . . . . . . . . . . . . 25

. . . . . . . . . . 26

. . . . . . . . . . . . . . . . 30

. . . . . . . . . . . . . . . 36

Contents 7

Parity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Hot Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Disk Rebuilds

Hot Swap . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

SCSI Drive States . . . . . . . . . . . . . . . . . . . . . . . 39

Logical Drive States

Enclosure Management . . . . . . . . . . . . . . . . . . . . 40

3 RAID Levels

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

. . . . . . . . . . . . . . . . . . . . . . . . . 38

. . . . . . . . . . . . . . . . . . . . . . 40

Selecting a RAID Level

RAID 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

RAID 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

RAID 5

RAID 10

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

RAID 50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

4 PERC 3/SC Features

Hardware Requirements . . . . . . . . . . . . . . . . . . . . . . 54

Configuration Features

SMART Technology

Configuration on Disk Configuration . . . . . . . . . . . . . . 55

Hardware Architecture Features

Array Performance Features

PERC 3/SC Fault Tolerance Features

. . . . . . . . . . . . . . . . . . . . . . 42

. . . . . . . . . . . . . . . . . . . . . . 54

. . . . . . . . . . . . . . . . . . . . . . 55

. . . . . . . . . . . . . . . . . 56

. . . . . . . . . . . . . . . . . . . 56

. . . . . . . . . . . . . . . 57

8 Contents

Software Utilities

. . . . . . . . . . . . . . . . . . . . . . . . . 57

Operating System Software Drivers

. . . . . . . . . . . . . . . . 58

PERC 3/SC Specifications . . . . . . . . . . . . . . . . . . . . . 58

PCI Bridge/CPU

. . . . . . . . . . . . . . . . . . . . . . . . 59

Cache Memory . . . . . . . . . . . . . . . . . . . . . . . . . 59

PERC 3/SC BIOS

. . . . . . . . . . . . . . . . . . . . . . . 60

Onboard Speaker . . . . . . . . . . . . . . . . . . . . . . . 60

Serial Port . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

SCSI Bus

. . . . . . . . . . . . . . . . . . . . . . . . . . . 60

SCSI Connectors . . . . . . . . . . . . . . . . . . . . . . . . 60

SCSI Termination . . . . . . . . . . . . . . . . . . . . . . . 60

SCSI Firmware

. . . . . . . . . . . . . . . . . . . . . . . . 61

RAID Management . . . . . . . . . . . . . . . . . . . . . . 61

5 PERC 3/DC and PERC 3/DCL Features

Hardware Requirements . . . . . . . . . . . . . . . . . . . . . . 64

Configuration Features

SMART Technology

. . . . . . . . . . . . . . . . . . . . . . 64

. . . . . . . . . . . . . . . . . . . . . . 65

Configuration on Disk . . . . . . . . . . . . . . . . . . . . . 65

Hardware Architecture Features . . . . . . . . . . . . . . . . . 66

Array Performance Features

Fault Tolerance Features

Software Utilities

. . . . . . . . . . . . . . . . . . . . . . . . . 68

Operating System Software Drivers

PERC 3/DC and PERC 3/DCL Specifications

PCI Bridge/CPU

. . . . . . . . . . . . . . . . . . . . . . . . 69

. . . . . . . . . . . . . . . . . . . 67

. . . . . . . . . . . . . . . . . . . . . . 67

. . . . . . . . . . . . . . . . 68

. . . . . . . . . . . 68

Cache Memory . . . . . . . . . . . . . . . . . . . . . . . . . 70

PERC 3/DC and PERC 3/DCL BIOS

Onboard Speaker

Serial Port

SCSI Bus

SCSI Connectors

SCSI Termination

. . . . . . . . . . . . . . . . . . . . . . . 70

. . . . . . . . . . . . . . . . . . . . . . . . . . . 70

. . . . . . . . . . . . . . . . . . . . . . . . . . . 70

. . . . . . . . . . . . . . . . . . . . . . . . 71

. . . . . . . . . . . . . . . . . . . . . . . 71

. . . . . . . . . . . . . . 70

9 Contents

SCSI Firmware . . . . . . . . . . . . . . . . . . . . . . . . 71

RAID Management . . . . . . . . . . . . . . . . . . . . . . 72

6 PERC 3/QC Features

Hardware Requirements . . . . . . . . . . . . . . . . . . . . . . 74

Configuration Features

SMART Technology

Configuration on Disk

Hardware Architecture Features

. . . . . . . . . . . . . . . . . . . . . . 74

. . . . . . . . . . . . . . . . . . . . . . 75

. . . . . . . . . . . . . . . . . . . . . 75

. . . . . . . . . . . . . . . . . 76

Array Performance Features . . . . . . . . . . . . . . . . . . . 76

Fault Tolerance Features . . . . . . . . . . . . . . . . . . . . . . 77

Software Utilities

. . . . . . . . . . . . . . . . . . . . . . . . . 77

Operating System Software Drivers . . . . . . . . . . . . . . . . 78

PERC 3/QC Specifications . . . . . . . . . . . . . . . . . . . . 78

PCI Bridge/CPU

. . . . . . . . . . . . . . . . . . . . . . . . 79

Cache Memory . . . . . . . . . . . . . . . . . . . . . . . . . 79

PERC 3/QC BIOS . . . . . . . . . . . . . . . . . . . . . . . 80

Onboard Speaker

. . . . . . . . . . . . . . . . . . . . . . . 80

Serial Port . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

SCSI Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

SCSI Connectors

SCSI Termination

. . . . . . . . . . . . . . . . . . . . . . . . 80

. . . . . . . . . . . . . . . . . . . . . . . 80

SCSI Firmware . . . . . . . . . . . . . . . . . . . . . . . . 81

RAID Management

. . . . . . . . . . . . . . . . . . . . . . 81

7 Configuring PERC 3

Configuring SCSI Physical Drives . . . . . . . . . . . . . . . . . 84

Current Configuration

Logical Drive Configuration

10 Contents

. . . . . . . . . . . . . . . . . . . . . . . 84

. . . . . . . . . . . . . . . . . . . . 87

Physical Device Layout . . . . . . . . . . . . . . . . . . . . . . 89

Configuring Arrays . . . . . . . . . . . . . . . . . . . . . . . . 92

Arranging Arrays

. . . . . . . . . . . . . . . . . . . . . . . 93

Creating Hot Spares . . . . . . . . . . . . . . . . . . . . . . 93

Creating Logical Drives . . . . . . . . . . . . . . . . . . . . 93

Configuration Strategies . . . . . . . . . . . . . . . . . . . . . 93

Maximizing Capacity

. . . . . . . . . . . . . . . . . . . . . 94

Maximizing Drive Availability . . . . . . . . . . . . . . . . . 94

Maximizing Drive Performance

. . . . . . . . . . . . . . . . 95

Assigning RAID Levels

. . . . . . . . . . . . . . . . . . . . . . 95

Configuring Logical Drives . . . . . . . . . . . . . . . . . . . . 96

Optimizing Data Storage . . . . . . . . . . . . . . . . . . . . . 96

Data Access Requirements

. . . . . . . . . . . . . . . . . . . 96

Array Functions . . . . . . . . . . . . . . . . . . . . . . . . 97

Planning the Array Configuration . . . . . . . . . . . . . . . . . 97

Using the Array Configuration Planner

Random Array Deletion

Overview

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

Configuration Module

. . . . . . . . . . . . . . . . . . . . . . 99

. . . . . . . . . . . . . . . . . . . . . 100

8 PERC 3/SC Hardware Installation

Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

Optional Equipment

PERC 3/SC Card Layout

Installation Steps

Step 1—Unpack

Step 2—Power Down

Step 3—Set Jumpers

Step 4—Set SCSI Termination

. . . . . . . . . . . . . . . . . . . . . . 102

. . . . . . . . . . . . . . . . . . . . . . 103

. . . . . . . . . . . . . . . . . . . . . . . . . 103

. . . . . . . . . . . . . . . . . . . . . . . . 104

. . . . . . . . . . . . . . . . . . . . . 104

. . . . . . . . . . . . . . . . . . . . . 105

. . . . . . . . . . . . . . . . . 108

. . . . . . . . . . . . . 98

11 Contents

Step 5—Install PERC 3/SC . . . . . . . . . . . . . . . . . . 111

Step 6—Connect SCSI Cables . . . . . . . . . . . . . . . . . 113

Step 7—Set Target IDs

. . . . . . . . . . . . . . . . . . . . 114

Step 8—Power On Host System . . . . . . . . . . . . . . . . 115

Step 9—Run PERC 3 BIOS Configuration Utility or WebBIOS
Utility

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

Step 10—Install Operating System Software Drivers . . . . . . 116

9 PERC 3/DC or PERC 3/DCL Hardware Installation

Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

Optional Equipment

PERC 3/DC Card Layout . . . . . . . . . . . . . . . . . . . . . . 119

. . . . . . . . . . . . . . . . . . . . . . 118

PERC 3/DCL Card Layout

. . . . . . . . . . . . . . . . . . . . . 120

Installation Steps . . . . . . . . . . . . . . . . . . . . . . . . . 120

Step 1—Unpack the PERC 3/DC or PERC 3/DCL

Step 2—Power Down . . . . . . . . . . . . . . . . . . . . . 121

Step 3—Set Jumpers

. . . . . . . . . . . . . . . . . . . . . 121

Step 4—Set SCSI Termination . . . . . . . . . . . . . . . . . 125

Step 5—Install the PERC 3/DC or PERC 3/DCL Controller . . 126

Step 6—Select and Set Target IDs for SCSI Devices

Step 7—Connect SCSI Cables . . . . . . . . . . . . . . . . . 128

Step 8—Power On Host System . . . . . . . . . . . . . . . . 130

Step 9—Run the PERC 3 BIOS Configuration Utility or WebBIOS
Configuration Utility

. . . . . . . . . . . . . . . . . . . . . 130

Step 10—Install Operating System Software Driver . . . . . . 131

Replacing a PERC 3/DC Containing a BC Chip with a PERC 3/DC
Containing a BE Chip

. . . . . . . . . . . . . . . . . . . . . . . 131

Using Driver 5.22.1 or 5.22.2 and Firmware 161J or 161N

Using Driver 5.30 and Firmware 1.70

10 PERC 3/QC Hardware Installation

. . . . . . . 121

. . . . . . 128

. . 131

. . . . . . . . . . . . . 131

12 Contents

Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

Optional Equipment . . . . . . . . . . . . . . . . . . . . . . 134

PERC 3/QC Card Layout . . . . . . . . . . . . . . . . . . . . . . 135

Installation Steps

. . . . . . . . . . . . . . . . . . . . . . . . . 136

Step 1—Unpack the PERC 3/QC Controller

Step 2—Power Down

. . . . . . . . . . . . . . . . . . . . . 137

Step 3—Set Jumpers . . . . . . . . . . . . . . . . . . . . . 137

Step 4—Set SCSI Termination . . . . . . . . . . . . . . . . . 140

SCSI Termination

. . . . . . . . . . . . . . . . . . . . . . . 141

Step 5—Install PERC 3/QC . . . . . . . . . . . . . . . . . . 143

Step 6—Connect SCSI Cables . . . . . . . . . . . . . . . . . 145

Step 7—Set Target IDs

. . . . . . . . . . . . . . . . . . . . 146

Step 8—Power on Host System . . . . . . . . . . . . . . . . 146

Step 9—Run the PERC 3 BIOS Configuration Utility or WebBIOS
Configuration Utility

. . . . . . . . . . . . . . . . . . . . . . 147

Step 10—Install Operating System Driver . . . . . . . . . . . 147

11 PERC 3 BIOS Configuration Utility

Configuration On Disk . . . . . . . . . . . . . . . . . . . . . . . 150

Starting the PERC 3 BIOS Configuration Utility

BIOS Configuration Utility Menu Options . . . . . . . . . . . . 151

Configure Menu

Initialize Menu

Objects Menu

Format Menu

Rebuild Menu . . . . . . . . . . . . . . . . . . . . . . . . . 158

Check Consistency Menu

. . . . . . . . . . . . . . . . . . . . . . . . 152

. . . . . . . . . . . . . . . . . . . . . . . . 153

. . . . . . . . . . . . . . . . . . . . . . . . . 153

. . . . . . . . . . . . . . . . . . . . . . . . . 158

. . . . . . . . . . . . . . . . . . . . 159

. . . . . . . . . . 136

. . . . . . . . . 150

13 Contents

Configuring Arrays and Logical Drives

Choosing the Configuration Method

Easy Configuration

New Configuration

View/Add Configuration

. . . . . . . . . . . . . . . . . . . . . . . 160

. . . . . . . . . . . . . . . . . . . . . . . 160

. . . . . . . . . . . . . . . . . . . . 161

. . . . . . . . . . . . . . 159

. . . . . . . . . . . . . . . 160

PERC 3/QC and PERC 3/DC Default Settings . . . . . . . . . 161

PERC 3/SC and PERC 3/DCL Default Settings . . . . . . . . . 161

Reserved Disk Space during Configuration

. . . . . . . . . . . 162

Designating Drives as Hot Spares

. . . . . . . . . . . . . . . . . 162

Using Easy Configuration . . . . . . . . . . . . . . . . . . . . . 163

Using New Configuration . . . . . . . . . . . . . . . . . . . . . 167

Using View/Add Configuration

Initializing Logical Drives

Batch Initialization

Individual Initialization

Deleting Logical Drives (Random Array Deletion)

. . . . . . . . . . . . . . . . . . 173

. . . . . . . . . . . . . . . . . . . . . 178

. . . . . . . . . . . . . . . . . . . . . . 178

. . . . . . . . . . . . . . . . . . . . 179

. . . . . . . . . 179

Formatting Physical Drives . . . . . . . . . . . . . . . . . . . . 180

Media Errors

. . . . . . . . . . . . . . . . . . . . . . . . . 180

Formatting Drives . . . . . . . . . . . . . . . . . . . . . . . 180

Rebuilding Failed Disk Drives . . . . . . . . . . . . . . . . . . . 182

Manual Rebuild – Rebuilding an Individual Drive

. . . . . . . . 182

Manual Rebuild – Batch Mode . . . . . . . . . . . . . . . . . 182

Using a Pre-loaded SCSI Drive “As-is” . . . . . . . . . . . . . . 183

Exiting the PERC 3 BIOS Configuration Utility . . . . . . . . . 184

12 Dell Manager

14 Contents

Setting Hardware Termination

. . . . . . . . . . . . . . . . . . 184

Clustering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185

Cluster Mode

Enabling and Disabling the Cluster Mode

. . . . . . . . . . . . . . . . . . . . . . . . . 185

. . . . . . . . . . . 185

Starting Dell Manager . . . . . . . . . . . . . . . . . . . . . . . 188

Management Menu Options

Using Dell Manager in Red Hat Linux GUI Mode

. . . . . . . . . . . . . . . . . . 189

. . . . . . . 189

Dell Manager Menu Options . . . . . . . . . . . . . . . . . . . 190

Initialize Menu

. . . . . . . . . . . . . . . . . . . . . . . . 190

Objects Menu . . . . . . . . . . . . . . . . . . . . . . . . . 190

Format Menu

. . . . . . . . . . . . . . . . . . . . . . . . . 194

Rebuild Menu . . . . . . . . . . . . . . . . . . . . . . . . . 195

Check Consistency Menu . . . . . . . . . . . . . . . . . . . 195

Reconstruct Menu

. . . . . . . . . . . . . . . . . . . . . . . 195

Designating Drives as Hot Spares

Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196

Initializing Logical Drives . . . . . . . . . . . . . . . . . . . . 197

Batch Initialization

Individual Initialization . . . . . . . . . . . . . . . . . . . . 198

Deleting Logical Drives (Random Array Deletion) . . . . . . . . 198

Formatting Physical Drives

Media Errors

Formatting Drives

Rebuilding Failed Disk Drives

Manual Rebuild – Rebuilding an Individual Drive

Manual Rebuild – Batch Mode

Exiting Dell Manager

13 Troubleshooting

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204

. . . . . . . . . . . . . . . . 195

. . . . . . . . . . . . . . . . . . . . . . 197

. . . . . . . . . . . . . . . . . . . . 199

. . . . . . . . . . . . . . . . . . . . . . . . . 199

. . . . . . . . . . . . . . . . . . . . . . . 200

. . . . . . . . . . . . . . . . . . . 201

. . . . . . . 201

. . . . . . . . . . . . . . . . 202

. . . . . . . . . . . . . . . . . . . . . . . 202

BIOS Boot Error Messages

Other BIOS Error Messages

Other Potential Problems

Audible Warnings

. . . . . . . . . . . . . . . . . . . . . . . . . 210

. . . . . . . . . . . . . . . . . . . . 205

. . . . . . . . . . . . . . . . . . . 208

. . . . . . . . . . . . . . . . . . . . . 209

Contents 15

14 Appendix A: SCSI Cables and Connectors

15 Appendix B: Warranties and Return Policy

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247

16 Contents

Figures

Figure 2-1. Example of Disk Striping . . . . . . . . . . . . . . . . 33

Figure 2-2. Example of Disk Mirroring

Figure 2-3. Example of Disk Spanning

Figure 2-4. Example of Parity

Figure 3-1. RAID 0 Array

Figure 3-2. RAID 1 Array

Figure 3-3. RAID 5 Array

Figure 3-4. RAID 10 Array

Figure 3-5. RAID 50 Array

. . . . . . . . . . . . . . . . . . . . 37

. . . . . . . . . . . . . . . . . . . . . . 44

. . . . . . . . . . . . . . . . . . . . . . 46

. . . . . . . . . . . . . . . . . . . . . . 48

. . . . . . . . . . . . . . . . . . . . . 50

. . . . . . . . . . . . . . . . . . . . . 52

Figure 8-1. PERC 3/SC Card Layout

Figure 8-2. Example of SCSI Termination

Figure 8-3. Termination of Internal SCSI Disk Arrays

Figure 8-4. PCI Slots on Motherboard

Figure 8-5. Installation of PERC 3/SC Card into Motherboard

Figure 8-6. Connecting SCSI Cables

Figure 9-1. PERC 3/DC Card Layout

Figure 9-2. PERC 3/DCL Card Layout

Figure 9-3. J11 Serial Port Pinout

. . . . . . . . . . . . . . . 34

. . . . . . . . . . . . . . . . 35

. . . . . . . . . . . . . . . 103

. . . . . . . . . . . . . 108

. . . . . . . 110

. . . . . . . . . . . . . . . 111

. . . 112

. . . . . . . . . . . . . . . . 113

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

. . . . . . . . . . . . . . . 120

. . . . . . . . . . . . . . . . 123

Figure 9-4. Termination of Internal SCSI Disk Arrays for PERC 3/DC and

3/DCL . . . . . . . . . . . . . . . . . . . . . 126

Figure 9-5. Installation of the PERC 3/DC and 3/DCL

Figure 9-6. Connecting SCSI Cables to PERC 3/DC and 3/DCL

Figure 10-1. PERC 3/QC Card Layout

Figure 10-2. J14 Serial Port Diagram

Figure 10-3. Example of Termination

. . . . . . . . . . . . . . . 135

. . . . . . . . . . . . . . . 139

. . . . . . . . . . . . . . . 141

Figure 10-4. Termination of Internal SCSI Disk Arrays

Figure 10-5. PCI Slots on Motherboard

. . . . . . . . . . . . . . 143

Figure 10-6. Installation of the PERC 3/QC Card

Figure 10-7. Connecting SCSI Cables

. . . . . . . . . . . . . . . 145

. . . . . . . 127

. . 129

. . . . . . 142

. . . . . . . . . 144

Figures 17

18 Figures

Tables

Table 1-1. Maximum Cable Length for SCSI Standards . . . . . . 26

Table 1-2. SCSI Bus Widths and Maximum Throughput

Table 2-1. Spanning for RAID 10 and RAID 50

Table 2-2. Types of Parity

Table 2-3. SCSI Drive States

Table 2-4. Logical Drive States

Table 3-1. RAID Levels

Table 3-2. RAID 0 Overview

Table 3-3. RAID 1 Overview

Table 3-4. RAID 5 Overview

Table 3-5. RAID 10 Overview

Table 3-6. RAID 50 Overview

Table 4-1. Configuration Features

Table 4-2. Configuration on Disk Features

Table 4-3. Hardware Architecture Features

Table 4-4. Array Performance Features

. . . . . . . . . . . . . . . . . . . . . 36

. . . . . . . . . . . . . . . . . . . 39

. . . . . . . . . . . . . . . . . . 40

. . . . . . . . . . . . . . . . . . . . . . 42

. . . . . . . . . . . . . . . . . . . . 43

. . . . . . . . . . . . . . . . . . . . 45

. . . . . . . . . . . . . . . . . . . . 47

. . . . . . . . . . . . . . . . . . . 49

. . . . . . . . . . . . . . . . . . . 51

. . . . . . . . . . . . . . . . . 54

. . . . . . . . . . . . . 55

. . . . . . . . . . . . 56

. . . . . . . . . . . . . . 56

Table 4-5. PERC 3/SC Fault Tolerance Features

Table 4-6. Software Utilities Features

Table 4-7. PERC 3/SC Specifications

Table 4-8. SCSI Firmware Support

Table 5-1. Configuration Features

Table 5-2. Configuration on Disk Features

Table 5-3. Hardware Architecture Features

Table 5-4. Array Performance Features

Table 5-5. Fault Tolerance Features

Table 5-6. Software Utilities

. . . . . . . . . . . . . . . . . . . 68

. . . . . . . . . . . . . . . 57

. . . . . . . . . . . . . . . 58

. . . . . . . . . . . . . . . . 61

. . . . . . . . . . . . . . . . . 64

. . . . . . . . . . . . . 65

. . . . . . . . . . . . 66

. . . . . . . . . . . . . . 67

. . . . . . . . . . . . . . . . 67

Table 5-7. PERC 3/DC and PERC 3/DCL Specifications

Table 5-8. SCSI Firmware

Table 6-1. Configuration Features

Table 6-2. Configuration on Disk Features

. . . . . . . . . . . . . . . . . . . . 71

. . . . . . . . . . . . . . . . . 74

. . . . . . . . . . . . . 75

. . . . . . 27

. . . . . . . . . . 36

. . . . . . . . . . 57

. . . . . . 68

Tables 19

Table 6-3. Hardware Architecture Features . . . . . . . . . . . . . 76

Table 6-4. Array Performance Features

Table 6-5. Fault Tolerance Features

Table 6-6. Software Utilities

. . . . . . . . . . . . . . . . . . . . 78

Table 6-7. PERC 3/QC Specifications

Table 6-8. SCSI Firmware

. . . . . . . . . . . . . . . . . . . . . 81

Table 7-1. Current Configuration for SCSI Channel 0

Table 7-2. Current Configuration for SCSI Channel 1

Table 7-3. Current Configuration for SCSI Channel 2

Table 7-4. Current Configuration for SCSI Channel 3

Table 7-5. Logical Drive Configuration

Table 7-6. Physical Device Layout

Table 7-7. Drives and Capacities for Each RAID Level

Table 7-8. Fault Tolerance Features for RAID Levels 0, 1 and 5

Table 7-9. Performance Characteristics for Each RAID Level

Table 7-10. Physical Drives Required for Each RAID Level

Table 7-11. Factors to Consider for Array Configuration

Table 7-12. Array Configuration Planner

Table 8-1. PERC 3/SC Jumpers

Table 8-2. J1 Termination Enable Settings

Table 8-3. J9 I2C Interface Connector Pinout

Table 8-4. J5 Serial Port Pinout

Table 8-5. J8 Hard Disk LED

. . . . . . . . . . . . . . . . . . 107

Table 8-6. J15 RUBI Slot Interrupt Steering

Table 8-7. J16, J17 RUBI Slot Interrupt Steering

Table 8-8. Target IDs

Table 9-1. Jumper Settings

. . . . . . . . . . . . . . . . . . . . . . . 115

. . . . . . . . . . . . . . . . . . . . 121

Table 9-2. J2 and J3 Termination Enable Settings

Table 9-3. J9 Onboard BIOS Enable Settings

Table 9-4. J10 NVRAM Clear Pinout

Table 9-5. J11 Serial Port Pinout

. . . . . . . . . . . . . . 76

. . . . . . . . . . . . . . . . 77

. . . . . . . . . . . . . . . . 78

. . . . . . . . 84

. . . . . . . . 85

. . . . . . . . 86

. . . . . . . . 87

. . . . . . . . . . . . . . . 87

. . . . . . . . . . . . . . . . . 89

. . . . . . . 94

. . 94

. . . . 95

. . . . . 95

. . . . . . 97

. . . . . . . . . . . . . . 98

. . . . . . . . . . . . . . . . . 105

. . . . . . . . . . . . 105

. . . . . . . . . . 106

. . . . . . . . . . . . . . . . . 106

. . . . . . . . . . . 107

. . . . . . . . 108

. . . . . . . . 122

. . . . . . . . . . . 122

. . . . . . . . . . . . . . 123

. . . . . . . . . . . . . . . . 123

20 Tables

Table 9-6. J13 Dirty Cache LED Pinout . . . . . . . . . . . . . . 124

Table 9-7. J14 SCSI Activity Pinout

Table 9-8. J16 and J18 TERMPWR Enable Settings

Table 9-9. J17 I2C Connector Pinout

Table 9-10. Target IDs for SCSI Devices

Table 10-1. PERC 3/QC Jumper Settings

Table 10-2. J2, J3, J5 and J7 Termination Enable Pinout

Table 10-3. J9, J10, J11 and J12 TERMPWR Enable Pinout

Table 10-4. J14 Serial Port Pinout

Table 10-5. J17 Dirty Cache LED Pinout

Table 10-6. J19 Onboard BIOS Enable Settings

Table 10-7. J23 External Battery Pinout

Table 10-8. Target IDs

. . . . . . . . . . . . . . . . . . . . . . 146

Table 11-1. BIOS Configuration Utility Menu Options

Table 11-2. Configuration Menu Options

Table 11-3. Adapter Menu Options

Table 11-4. Logical Drive Menu Options

Table 11-5. Physical Drive Menu Options

Table 11-6. SCSI Channel Menu Options

Table 11-7. Battery Information Menu Options

Table 11-8. PERC 3/QC and PERC 3/DC Default Settings

Table 11-9. PERC 3/SC and PERC 3/DCL Default Settings

Table 11-10. Rebuild Types

. . . . . . . . . . . . . . . . . . . . 182

Table 12-1. Command Used to Start Dell Manager

Table 12-2. Management Menu Options

Table 12-3. Adapter Menu Options

Table 12-4. Logical Drive Menu Options

Table 12-5. Logical Drive Default Settings

Table 12-6. Physical Drive Menu Options

Table 12-7. SCSI Channel Options

Table 12-8. Battery Backup Menu Items

. . . . . . . . . . . . . . . . 124

. . . . . . . 124

. . . . . . . . . . . . . . . 125

. . . . . . . . . . . . . 128

. . . . . . . . . . . . . 137

. . . . . 138

. . . 138

. . . . . . . . . . . . . . . . 139

. . . . . . . . . . . . . 139

. . . . . . . . . . 140

. . . . . . . . . . . . . 140

. . . . . . . 151

. . . . . . . . . . . . . . 152

. . . . . . . . . . . . . . . . 153

. . . . . . . . . . . . . . 155

. . . . . . . . . . . . . 156

. . . . . . . . . . . . . 157

. . . . . . . . . . 157

. . . . . 161

. . . . 161

. . . . . . . . 188

. . . . . . . . . . . . . . 189

. . . . . . . . . . . . . . . . 190

. . . . . . . . . . . . . . 191

. . . . . . . . . . . . . 191

. . . . . . . . . . . . . 192

. . . . . . . . . . . . . . . . . 193

. . . . . . . . . . . . . 193

Tables 21

Table 12-9. Rebuild Types . . . . . . . . . . . . . . . . . . . . 201

Table 13-1. General Problems and Suggested Solutions

Table 13-2. BIOS Boot Error Messages

Table 13-3. Other BIOS Error Messages

Table 13-4. Other Potential Problems

Table 13-5. Audible Warnings

. . . . . . . . . . . . . . . . . . 210

. . . . . . . . . . . . . 205

. . . . . . . . . . . . . 208

. . . . . . . . . . . . . . 209

. . . . . . 204

22 Tables

SECTION 1

Overview

PERC 3 Overview

PERC 3 Features

PERC 3 Overview

The Dell™ PowerEdge™ Expandable RAID Controller 3 (PERC 3) PCI
card is a high-performance, intelligent peripheral component interconnect
(PCI)-to-SCSI host adapter with RAID control capabilities. PERC 3
provides system availability, high performance, and fault-tolerant disk
subsystem management. PERC 3 is an ideal RAID solution for the internal
storage of Dell’s workgroup, departmental, and enterprise systems. PERC 3
offers a cost-effective way to implement RAID in a server.

The PERC 3/QC low voltage differential (LVD) PCI RAID card provides
four SCSI channels. The PERC 3/DC and PERC 3/DCL LVD PCI RAID

www.dell.com | support.dell.com

card provides two SCSI channels. The PERC 3/SC LVD PCI RAID card
provides one SCSI channel.

NOTE: The information

in this document applies
to PERC 3/QC, PERC
3/DC, PERC 3/DCL and
PERC 3/SC.

With LVD, you can use cables up to 25 meters long. Throughput on each
SCSI channel can be as high as 160 MB/s. PERC 3 supports both an LVD
SCSI bus and a single-ended SCSI bus.

PERC 3 64-bit LVD is a high-performance, intelligent PCI-to-SCSI host
adapter with RAID control capabilities. PERC 3 64-bit LVD requires no
special motherboard PCI expansion slot.

PERC 3 Features

The PERC 3 features include:

• Wide Ultra3 LVD SCSI performance of up to 160 MB/s

• PERC 3/QC and PERC 3/DC support 128 MB of synchronous
dynamic random access memory (SDRAM.)

• The PERC 3/DCL supports 64 MB of SDRAM.

• The PERC 3/SC supports 32 MB of SDRAM.

• 64-bit PCI host interface (only on PERC 3/QC and PERC 3/DC)

• The PERC 3/QC, PERC 3/DC and PERC 3/DCL have an on-board
i960RN processor to improve controller performance and offload host
Central Processing Unit (CPU.)

24 Overview

• The PERC 3/SC has a on-board i960RM processor to improve
controller performance and offload host CPU.

• Two internal and four external connectors for the PERC 3/QC, two
internal and two external connectors for the PERC 3/DC and PERC
3/DCL, and one internal and one external connector for the PERC
3/SC

• RAID levels 0 (striping), 1 (mirroring), 5 (distributed parity), 10
(combination of striping and mirroring), and 50 (combination of
striping and distributed parity)

• Advanced array configuration and management utilities

• Battery backup for up to 72 hours for the PERC 3/QC and PERC
3/DC

• Up to 12 SCSI drives per channel using the Dell PowerVault 21xS
storage system or 14 SCSI drives using the Dell PowerVault 22xS

SCSI Channels

The PERC 3/QC controller card includes four SCSI channels. There are two
QLogic

The PERC 3/DC and PERC 3/DCL controller cards include two SCSI
channels. There is one QLogic 12160 chip, which controls two SCSI
channels.

The PERC 3/SC controller card has one SCSI channel. There is one QLogic
10160 chip.

®

12160 chips; each chip controls two SCSI channels.

Non-volatile Random Access Memory (NVRAM) and Flash Read­only Memory (ROM)

A 32 KB x 8 NVRAM stores RAID system configuration information. The
PERC 3 firmware is stored in flash ROM for easy upgrade.

SCSI Connectors

PERC 3/QC has four ultra-high-density 68-pin external connectors for the
external storage subsystem and two high-density 68-pin internal connectors.

NOTE: Clustering is not

supported by PERC 3/QC
or PERC 3/DCL.

PERC 3/DC and PERC 3/DCL have two ultra-high-density 68-pin external
connectors for the external storage subsystem and two high-density 68-pin
internal connectors.

Overview 25

PERC 3/SC has one ultra-high-density 68-pin external connector for the
external storage subsystem and one high-density 68-pin internal connector.

Single-Ended and LVD SCSI Buses

The SCSI standard defines two electrical buses: a single-ended bus and an
LVD bus. PERC 3 supports both standards.

Maximum Cable Length for SCSI Standards

Table 1-1 displays the maximum length of cable that you can use for various
SCSI standards.

www.dell.com | support.dell.com

Table 1-1. Maximum Cable Length for SCSI Standards

SCSI Standard Single-ended LVD Maximum # of

Drives

SCSI I 6 m 12 m 7

Fast SCSI 6 m 12 m 7

Fast Wide SCSI 6 m 12 m 15

Ultra SCSI 1.5 m 12 m 7

Ultra SCSI 3 m 12 m 3

Wide Ultra SCSI N/A 12 m 15

Wide Ultra SCSI 1.5 m 12 m 7

Wide Ultra SCSI 3 m 12 m 3

Ultra 2 SCSI N/A 25 m 1

Ultra 2 SCSI N/A 12 m 7

Wide Ultra 2 SCSI N/A 25 m 1

Wide Ultra 2 SCSI N/A 12 m 15

SCSI Bus Widths and Maximum Throughput

Table 1-2 displays the SCSI bus widths and maximum throughput for each
of the SCSI standards.

26 Overview

Table 1-2. SCSI Bus Widths and Maximum Throughput

SCSI Standard SCSI Bus Width SCSI Throughput

SCSI I 8 bits 5 MB/s

Fast SCSI 8 bits 10 MB/s

Fast Wide SCSI 16 bits 20 MB/s

Ultra SCSI 8 bits 20 MB/s

Wide Ultra SCSI 16 bits 40 MB/s

Ultra 2 SCSI 8 bits 40 MB/s

Wide Ultra 2 SCSI 16 bits 80 MB/s

160M SCSI 8 bits 80 MB/s

Wide 160M SCSI 16 bits 160 MB/s

Operating System Support

PERC 3 supports the following operating systems:

•Microsoft

®

Windows® 2000: Server, Advanced Server, Small Business

Server

•Microsoft Windows NT

®

4: Server, Terminal Server, Enterprise Server,

Small Business Server

• Microsoft NET: Server, Advanced Server

• Microsoft SBS 2000

•Novell

®

NetWare® 5.x, 6.x

• Red Hat Linux 7.x

• DOS, including ASPI

®

support

Overview 27

www.dell.com | support.dell.com

28 Overview

SECTION 2

Introduction to RAID

RAID Definition

PERC 3 Host-Based RAID Solution

Components and Features

RAID Definition

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. Input/output
(I/O) improves because several disks can be accessed simultaneously.
Although hard drive capabilities have improved drastically, actual
performance has improved only three to four times in the last decade. In
comparison, computing performance has improved over 50 times during the
same time period. Implementing RAID improves the performance of the
disk subsystem.

www.dell.com | support.dell.com

RAID systems also improve data storage availability and fault tolerance.
Data loss caused by a hard drive failure can be recovered by reconstructing
missing data from the remaining data and parity drives.

PERC 3 Host-Based RAID Solution

PERC 3 is a peripheral component interconnect (PCI) adapter card that is
installed in any available PCI expansion slot in a host system. It is a host­based RAID solution, meaning that the RAID controller puts all of the
RAID intelligence on an adapter card that is installed in a network server.

The array controller resides on the bus (for example, a PCI or EISA bus) in
the host computer and has its own central processing unit (CPU) to
generate the parity and handle other RAID functions. A bus-based
controller can transfer data at the speed of the host bus (PCI, ISA, EISA,
VL-Bus), but is limited to the bus it is designed for. PERC 3 resides on a
PCI bus, which can handle data transfer at up to 528 MB/s. With PERC 3,
each channel can handle data transfer rates up to 160 MB/s per SCSI
channel. The available sequential data transfer rate is determined by the
following factors:

• The sustained data transfer rate on the motherboard PCI bus

• The sustained data transfer rate on the i960RN (i960RM for the PERC
3/SC) PCI to PCI bridge

30 Introduction to RAID

• The sustained data transfer rate of the SCSI controller

• The sustained data transfer rate of the SCSI devices

• The number of SCSI channels and SCSI hard drives

Components and Features

RAID versions, or levels, are specifications that describe a system for
ensuring the availability and stability of data stored on large disk
subsystems. A RAID system can be implemented in a number of different
levels). PERC 3 supports RAID levels 0, 1, 5, 10 (1+0), and 50 (5+0).

Physical Array

A RAID array is a collection of physical disk drives governed by the RAID
management software. A RAID array appears to the host computer as one or
more logical drives.

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.

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.

Fault tolerance is often associated with system availability (high mean time
between failure, MTFB) 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 the repair of the problem. To make this possible, PERC 3
supports hot spare disks, and the auto-rebuild feature.

Introduction to RAID 31

A hot spare is an unused online 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
subsystem, the failed drive is automatically rebuilt on the spare drive. The
RAID disk array continues to handle requests while the rebuild occurs.

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

Consistency Check

www.dell.com | support.dell.com

In RAID, check consistency verifies the correctness of redundant data in an
array. 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.

Disk Striping

Disk striping allows you to write data across multiple disk drives instead of
just one disk drive. Disk striping involves partitioning each drive storage
space into stripes that can vary in size from 2 KB to 128 KB. These stripes
are interleaved in a repeated sequential manner. The combined storage
space is composed of stripes from each drive. PERC 3 supports stripe sizes
of 2 KB, 4 KB, 8 KB, 16 KB, 32 KB, 64 KB, and 128 KB.

32 Introduction to RAID

For example, in a four-disk system using only disk striping (as 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.

Figure 2-1. Example of Disk Striping

Segment 1
Segment 5
Segment 9

Segment 2
Segment 6

Segment 10

Segment 3
Segment 7

Segment 11

Segment 4
Segment 8

Segment 12

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.

Stripe Size

The stripe size is the length of the interleaved data segments that PERC 3
writes across multiple drives. PERC 3 supports stripe sizes of 2 KB, 4 KB,
8 KB, 16 KB, 32 KB, 64 KB, or 128 KB.

Introduction to RAID 33

Disk Mirroring

With 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 contents of the disk are completely written to a second disk, it
does not matter if 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.

www.dell.com | support.dell.com

Figure 2-2. Example of Disk Mirroring

Segment 1
Segment 2
Segment 3
Segment 4 Segment 4 Duplicated

Segment 1 Duplicated
Segment 2 Duplicated
Segment 3 Duplicated

34 Introduction to RAID

Disk Spanning

Disk spanning allows multiple physical 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.
For example, four 20 GB drives can be combined to appear to the operating
system as a single 80 GB drive.

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

Figure 2-3. Example of Disk Spanning

60 GByte 60 GByte

Can Be Accessed as

One 120 GByte Drive

60 GByte 60 GByte

Can Be Accessed as

One 120 GByte Drive

Introduction to RAID 35

Spanning for RAID 10 or RAID 50

Table 2-1 describes how to configure RAID 10 and RAID 50 by spanning.

NOTE: Spanning two

contiguous RAID 0
logical drives does not
produce a new RAID level
or add fault tolerance. It
does increase the size of
the logical volume and
improves performance by
doubling the number of
spindles.

www.dell.com | support.dell.com

Table 2-1. Spanning for RAID 10 and RAID 50

Level Description

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

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

NOTE: Refer to Chapter 11 "PERC 3 BIOS Configuration

Utility" for the configuration procedure for spanning RAID 1
logical drives.

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

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

NOTE: Refer to Chapter 11 "PERC 3 BIOS Configuration

Utility" for the configuration procedure for spanning RAID 5
logical drives.

Parity

Parity generates a set of redundancy data from two or more parent data sets.
The redundancy data can be used to 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 shown in Table 2-2.

Table 2-2. Types of Parity

36 Introduction to RAID

Parity Type Description

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

additional disk.

Distributed The parity data is distributed across all drives in the 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. Parity provides redundancy for one drive failure without
duplicating the contents of entire disk drives, but parity generation can slow
the write process. A dedicated parity scheme during normal read/write
operations is shown in Figure 2-4.

Figure 2-4. Example of Parity

Parity

Generator

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.

PERC 3 implements automatic and transparent rebuilds using hot spare
drives, providing a high degree of fault tolerance and zero downtime. The
PERC 3 RAID management software allows you to specify physical drives as
hot spares. When a hot spare is needed, PERC 3 assigns the hot spare that
has a capacity closest to and at least as great as that of the failed drive to
take the place of the failed drive.

Introduction to RAID 37

NOTE: Refer to Chapter

11 "PERC 3 BIOS
Configuration Utility" for
the procedures used to
designate a drive as a hot
spare.

There are two types of hot spares:

• Global Hot Spare

• Dedicated Hot Spare

Global Hot Spare

A global hot spare drive can be used to 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.

www.dell.com | support.dell.com

NOTE: Refer to Chapter

11"PERC 3 BIOS
Configuration Utility" for
the procedures used to
designate a drive as a hot
spare.

Dedicated Hot Spare

A dedicated hot spare can be used to 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 fail over. 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 made available in the array management software. PERC 3
offers the ability to 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:

• Hot spares are used only in arrays with redundancy, for example, RAID
levels 1, 5, 10, and 50.

• A hot spare connected to a specific PERC 3 controller can be used to
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’s 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 GB drive, the hot spare
must be 18 GB or larger.

38 Introduction to RAID

Disk Rebuilds

You can rebuild a disk drive by recreating the data that had been stored on
the drive before the drive failed.

Rebuilding can be done only in arrays with data redundancy, which includes
as RAID 1, 5, 10 and 50.

A hot spare can be used to rebuild disk drives in RAID 1, 5, 10, or 50
systems. If a hot spare is not available, the failed disk drive must be replaced
with a new disk drive so that the data on the failed drive can be rebuilt.

Using hot spares, PERC 3 can automatically and transparently rebuild failed
drives with user-defined rebuild rates. If a hot spare is available, the rebuild
can start automatically when a drive fails. PERC 3 automatically restarts the
system and the rebuild if the system goes down during a rebuild.

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 is
totally dedicated to rebuilding the failed drive.

The PERC 3 rebuild rate can be configured between 0% and 100%. At 0%,
the rebuild is done only if the system is not doing anything else. At 100%,
the rebuild has a higher priority than any other system activity. The default
rebuild rate is 30%.

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 will occur automatically if it is placed in the same drive bay as the
failed drive it is replacing. PERC 3 can be configured to detect the new disks
and to rebuild the contents of the disk drive automatically.

SCSI Drive States

The SCSI drive states are listed in Table 2-3.

Table 2-3. SCSI Drive States

State Description

Online

(ONLIN)

The drive is working normally and is a part of a configured
logical drive.

Introduction to RAID 39

Table 2-3. SCSI Drive States

State Description

Ready

(READY)

Hot Spare

(HOTSP)

Fail (FAIL) A fault has occurred in the drive, placing it out of service.

Rebuild (REB) The drive is being rebuilt with data from a failed drive.

The drive is functioning normally but is not part of a
configured logical drive and is not designated as a hot spare.

The drive is powered up and ready for use as a spare in case an
online drive fails.

(continued)

www.dell.com | support.dell.com

Logical Drive States

The logical drive states are listed in Table 2-4.

Table 2-4. Logical Drive States

State Description

Optimal The drive operating condition is good. All configured drives are

online.

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

configured drives has failed or is offline.

Failed The drive has failed.

Offline The drive is not available to the RAID controller.

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 separate from it. 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.

40 Introduction to RAID

SECTION 3

RAID Levels

Overview

Selecting a RAID Level

RAID 0

RAID 1

RAID 5

RAID 10

RAID 50

Overview

There are six official RAID levels (RAID 0 through RAID 5.) PERC 3
supports RAID levels 0, 1, 5, 10, and 50. The RAID levels that PERC 3
supports are shown in Table 3-1.

Table 3-1. RAID Levels

RAID
Level

0Standard

www.dell.com | support.dell.com

PERC 3 also supports independent drives (configured as RAID 0.)

1Standard

5Standard

1+0 Combination of RAID 0 and RAID 1

5+0 Combination of RAID 0 and RAID 5

Typ e

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:

• The number of physical drives in the disk array

• The capacity of the physical drives in the array

• The need for data redundancy

• The disk performance requirements

42 RAID Levels

RAID 0

RAID 0 provides disk striping across all drives in the RAID subsystem. 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.

By breaking up a large file into smaller blocks, PERC 3 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 is
also used to denote an “independent” or single drive.

Table 3-2 provides an overview of RAID 0.

Table 3-2. RAID 0 Overview

Uses

Strong Points

Weak Points

Drives

RAID 0 provides high data throughput, especially for
large files. Any environment that does not require
fault tolerance.

Provides increased data throughput for large files. No
capacity loss penalty for parity.

Does not provide fault tolerance. All data lost if any
drive fails.

1 to 32

RAID Levels 43

Figure 3-1 displays an example of a RAID 0 array.

Figure 3-1. RAID 0 Array

www.dell.com | support.dell.com

44 RAID Levels

Segment 1
Segment 5
Segment 7

Segment 2
Segment 6

Segment 10

Segment 3
Segment 7

Segment 11

Segment 4
Segment 8

Segment 12

RAID 1

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, as shown in Figure 3-2. Table 3­3 provides an overview of RAID 1.

Table 3-3. RAID 1 Overview

Uses

Strong Points

Weak Points

Drives 2

Use RAID 1 for small databases or any other
environment that requires fault tolerance but small
capacity.

RAID 1 provides complete data redundancy. RAID 1 is
ideal for any application that requires fault tolerance
and minimal capacity.

RAID 1 requires twice as many disk drives.
Performance is impaired during drive rebuilds.

RAID Levels 45

Figure 3-2. RAID 1 Array

www.dell.com | support.dell.com

Segment 1
Segment 2
Segment 3
Segment 4 Segment 4 Duplicated

Segment 1 Duplicated
Segment 2 Duplicated
Segment 3 Duplicated

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 3-4 provides an overview of RAID 5.

46 RAID Levels

Table 3-4. RAID 5 Overview

Uses

Strong Points

Weak Points

Drives

RAID 5 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, PERC 3 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.

Provides data redundancy and good performance in
most environments

Disk drive performance will be 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.

3 to 32

RAID Levels 47

Figure 3-3 displays an example of a RAID 5 array.

Figure 3-3. RAID 5 Array

www.dell.com | support.dell.com

Data Flow

Disk 1 Disk 2 Disk 3 Disk 4 Disk 5 Disk 6

Segment 1
Segment 7

Parity (9–12)

Note: Parity is distributed across drives in the array.

Segment 2
Segment 8

Segment 3
Segment 9

Parity (5–8)

RAID 10

RAID 10 is a combination of RAID 0 and RAID 1. RAID 10 has mirrored
drives. RAID 10 breaks up data into smaller blocks, and then mirrors the
blocks of data to each RAID 1 RAID set. Each RAID 1 RAID 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.
RAID 10 can sustain one to four drive failures while maintaining data
integrity if each failed disk is in a different RAID 1 array.

Table 3-5 provides an overview of RAID 10.

48 RAID Levels

Segment 4

Segment 10

Segment 5

Segment 11

Parity (1–4)

Segment 6

Segment 12

Table 3-5. RAID 10 Overview

Uses

Strong Points

Weak Points

Drives

RAID 10 works best for 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.

RAID 10 provides both high data transfer rates and
complete data redundancy.

RAID 10 requires twice as many drives as all other
RAID levels except RAID 1.

2n, where n is greater than 1. The maximum number
of drives is 16.

RAID Levels 49

Figure 3-4. RAID 10 Array

D

Data Flow

www.dell.com | support.dell.com

RAID 1

Disk 1 Disk 4Disk 3

Segment 1
Segment 3
Segment 5

Disk 2

Segment 1
Segment 3
Segment 5

RAID 0

Segment 2
Segment 4
Segment 6

RAID 1

Segment 2
Segment 4
Segment 6

RAID 50

RAID 50 provides the features of both RAID 0 and RAID 5. RAID 50
includes both parity and disk striping across multiple drives. 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, and then stripes the blocks of
data to each RAID 5 array. RAID 5 breaks up data into smaller blocks,
calculates parity by performing an exclusive-or on the blocks, and 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.

50 RAID Levels

RAID 50 can sustain one to four drive failures while maintaining data
integrity if each failed disk is in a different RAID 5 array.

Table 3-6 provides an overview of RAID 50.

Table 3-6. RAID 50 Overview

Uses

Strong Points

Weak Points

Drives

RAID 50 works best when used with data that requires
high reliability, high request rates, and high data
transfer and medium to large capacity.

RAID 50 provides high data throughput, data
redundancy, and very good performance.

Requires 2 to 4 times as many parity drives as RAID 5.

6 to 256 (Eight arrays x 32 stripes = 256 drives)

RAID Levels 51

Figure 3-5 displays an example of a RAID 50 array.

Figure 3-5. RAID 50 Array

www.dell.com | support.dell.com

Data Flow

Disk 1 Disk 2 Disk 3

Segment 1
Segment 6

Parity (9-10)

RAID 5

Segment 2
Parit y (5-6)
Segment 9

Parity (1-2)
Segment 5

Segment 10

RAID 0

Disk 4 Disk 5 Disk 6

Segment 3
Segment 8

Parity (11-12)

RAID 5

Segment 4
Parity (7-8)

Segment 11

Parity (3-4)
Segment 7

Segment 12

52 RAID Levels

SECTION 4

PERC 3/SC Features

Hardware Requirements

Configuration Features

Hardware Architecture Features

Array Performance Features

PERC 3/SC Fault Tolerance Features

Software Utilities

Operating System Software Drivers

PERC 3/SC Specifications

Hardware Requirements

PERC 3/SC has one SCSI) channel that supports 160M and Wide SCSI at
data transfer rates up to 160 MB/s. The SCSI channel supports up to 15
Wide devices or up to seven narrow devices.

PERC 3/SC can be installed in a Dell™ PowerEdge™ computer with a
motherboard that has 5 V, 32- or 64-bit PCI expansion slots. The computer
should have an Intel

®

Pentium® II or higher central processing unit (CPU),
a diskette drive, a color monitor and video graphics adapter (VGA) card, and
a keyboard. A mouse is recommended.

www.dell.com | support.dell.com

Configuration Features

Table 4-1 lists the configuration features for the PERC 3/SC controller.

Table 4-1. Configuration Features

Specification Feature

RAID levels 0, 1, 5, 10, and 50.

SCSI channels 1

Maximum number of drives per
channel

Array interface to host PCI 2.2

Drive interface Wide 160M

Cache memory size 32 MB

Cache function Write-back, write-through, adaptive

Multiple logical drives/arrays per
controller

Maximum number of PERC 3/SC
controller per system

Online capacity expansion Yes

Dedicated and pool hot spare Yes

Flashable firmware Yes

Hot swap devices supported Yes

15

read-ahead, non-read-ahead, read­ahead

Up to 40 logical drives per controller

Contact your Dell representative.

54 PERC 3/SC Features

Table 4-1. Configuration Features

Specification Feature

Non-disk devices supported No

Mixed capacity hard disk drives Yes

Number of 16-bit internal connectors 1

(continued)

SMART Technology

The PERC 3/SC self-monitoring analysis and reporting technology
(SMART) detects predictable drive failures. SMART monitors the internal
performance of all motors, heads, and drive electronics.

Configuration on Disk Configuration

Configuration on Disk (drive roaming) saves configuration information
both in non-volatile random access memory (NVRAM) on PERC 3/SC and
on the disk drives attached to PERC 3/SC. If the controller is replaced, the
new controller detects the actual RAID configuration from the
configuration information on the drives. This maintains the integrity of the
data on each drive, even if the drives have changed their target ID.

Drive roaming is supported across channels on the same controller. Drive
roaming across channels is not supported when cluster mode is enabled.
Table 4-2 lists the Configuration on Disk features for the PERC 3/SC
controller.

Table 4-2. Configuration on Disk Features

Specification Feature

Support for hard disk drives with
capacities of more than 8 gigabytes (GB)

Online RAID level migration Yes

RAID remapping Yes

No reboot necessary after expansion Yes (only if virtual sizing is

More than 200 qtags per array Yes

Hardware clustering support on the board Yes

Ye s

enabled)

NOTE: Configuration on

Disk does not work if you
change both the adapter,
and the SCSI connectors
to different connectors on
the new adapter. It will
work only if you make one
change at a time.

PERC 3/SC Features 55

Table 4-2. Configuration on Disk Features

Specification Feature

User-specified rebuild rate Yes

(continued)

Hardware Architecture Features

The PERC 3/SC hardware architecture features are shown in Table 4-3.

Table 4-3. Hardware Architecture Features

www.dell.com | support.dell.com

Specification Feature

Processor Intel i960RM 100MHz

SCSI controller(s) One QLogic

controller

Size of flash ROM 1 MB

Amount of NVRAM 32 KB

Hardware-exclusive OR (XOR)
assistance

Direct I/O Yes

SCSI bus termination Active, single-ended or low voltage

Double-sided dual in-line memory
modules (DIMMs)

Auxiliary TermPWR source No

Direct I/O bandwidth 132 MB/s

Ye s

differential (LVD)

Ye s

®

10160 Single SCSI

Array Performance Features

The PERC 3/SC array performance features are shown in Table 4-4.

Table 4-4. Array Performance Features

56 PERC 3/SC Features

Specification Feature

Host data transfer rate 132 MB/s

Drive data transfer rate 160 MB/s

Table 4-4. Array Performance Features

Specification Feature

Maximum scatter/gathers 26 elements

Maximum size of I/O requests 6.4 MB in 64 KB stripes

Maximum queue tags per drive As many as the drive can accept.

Stripe sizes 2 KB, 4 KB, 8 KB, 16 KB, 32 KB,

Maximum number of concurrent
commands

Support for multiple initiators Yes

(continued)

64 KB, or 128 KB

255

PERC 3/SC Fault Tolerance Features

The PERC 3/SC fault tolerance features are shown in Table 4-5.

Table 4-5. PERC 3/SC Fault Tolerance Features

Specification Feature

Support for SMART Yes

Drive failure detection Automatic

Drive rebuild using hot spares Automatic

Manual replacement of drives without system
shutdown

Parity generation and checking Yes

Ye s

Software Utilities

The PERC 3/SC software utilities are shown in Table 4-6.

Table 4-6. Software Utilities Features

Specification Feature

Graphical user interface Yes

Management utility Yes

PERC 3/SC Features 57

Table 4-6. Software Utilities Features

Specification Feature

Bootup configuration using the PERC BIOS
configuration utility (Ctrl–M)

Online read, write, and cache policy switching Yes

Intranet support Yes

(continued)

Ye s

Operating System Software Drivers

www.dell.com | support.dell.com

Operating System Drivers

PERC 3/SC includes a disk operating system (DOS) software configuration
utility and drivers for Microsoft

®

Novell

NetWare® 5.x, 6.x, and Red Hat Linux 7.x.

®

Windows NT® V4.0, Windows® 2000,

PERC 3/SC Specifications

The PERC 3/SC specifications are shown in Table 4-7.

Table 4-7. PERC 3/SC Specifications

Parameter Specification

Card size Half-length PCI adapter card size (6.875" X 4.2")

Processor Intel i960RM™ 64-bit RISC processor @

100 MHz

Bus type PCI 2.2

PCI controller Intel i960RM

Bus data transfer rate Up to 132 MB/s at 32/33 MHz

Basic input/output system
(BIOS)

Cache configuration 32 MB

Firmware 1 MB × 8 flash ROM

Non-volatile random access
memory (RAM)

Operating voltage 5 V, 3.3 V

PERC 3/SC BIOS

32 KB × 8 for storing RAID configuration

58 PERC 3/SC Features

Table 4-7. PERC 3/SC Specifications

Parameter Specification

SCSI controller One SCSI controller for 160M and Wide support

SCSI data transfer rate Up to 160 MB/s per channel

SCSI bus Low-voltage differential (LVD) or single-ended

SCSI termination Active

Termination disable Automatic through cable and device detection

Devices per SCSI channel Up to 15 wide or seven narrow SCSI devices

SCSI device types Synchronous or asynchronous

RAID levels supported 0, 1, 5, 10, and 50

SCSI connectors One 68-pin internal high-density connectors for

16-bit SCSI devices. One ultra-high density 68­pin external connectors for 160M and Wide
SCSI.

Serial port 3-pin RS232C-compatible connector (for

manufacturing use only)

(continued)

PCI Bridge/CPU

PERC 3/SC uses the Intel i960RM PCI bridge with an embedded i960RM
RISC processor running at 100 MHz. The RM bridge handles data transfers
between the primary (host) PCI bus, the secondary PCI bus, cache memory,
and the SCSI bus. The DMA controller supports chaining and unaligned
data transfers. The embedded i960JT CPU directs all controller functions,
including command processing, SCSI bus transfers, RAID processing, drive
rebuilding, cache management, and error recovery.

Cache Memory

32 MB of PERC 3/SC cache memory resides in a memory bank. PERC 3/SC
supports write-through or write-back caching, selectable for each logical
drive. To improve performance in sequential disk accesses, the PERC 3/SC
controller uses read-ahead caching by default. You can disable read-ahead
caching.

PERC 3/SC Features 59

PERC 3/SC BIOS

The BIOS resides on a 1 MB × 8 flash ROM for easy upgrade. The PERC
3/SC BIOS supports INT 13h calls to boot DOS without special software or
device drivers. The PERC 3/SC BIOS provides an extensive setup utility
that can be accessed by pressing <Ctrl> <M> at BIOS initialization. The
PERC 3/SC BIOS Configuration Utility is described in Chapter 11.

Onboard Speaker

The PERC 3/SC controller has an onboard tone generator for audible
warnings when system errors occur. Audible warnings can be generated

www.dell.com | support.dell.com

through this speaker. The audible warnings are listed in Chapter 13.

Serial Port

PERC 3/SC includes a 3-pin RS232C-compatible serial port connector. This
is for manufacturing use only.

SCSI Bus

PERC 3/SC has one Wide 160M SCSI channels that support both LVD and
single-ended devices with active termination. Synchronous and
asynchronous devices are supported. PERC 3/SC provides automatic
termination disable via cable detection. The SCSI channel supports up to
15 wide or seven non-wide SCSI devices at speeds up to 160 MB/s.

60 PERC 3/SC Features

SCSI Connectors

PERC 3/SC has two types of SCSI connectors:

• One 68-pin high density internal connector

• One 68-pin external ultra-high-density connector

Only one connector type can be used for the SCSI channel at any one time.

SCSI Termination

PERC 3/SC uses active termination on the SCSI bus conforming to SCSI-2
and SCSI-3 specifications. Termination enable/disable is automatic through
cable detection.

SCSI Firmware

The PERC 3/SC firmware handles all RAID and SCSI command processing
and also supports the features shown in Table 4-8.

Table 4-8. SCSI Firmware Support

Feature Description

Disconnect/
reconnect

Tagged command
queuing

Scatter/gather Single command can transfer data to and from different

Multi-threading Up to 255 simultaneous commands with elevator sorting

Stripe size Variable for all logical drives: 2 KB, 4 KB, 8 KB, 16 KB,

Rebuild Multiple rebuilds and consistency checks with user-

Optimizes SCSI bus utilization

Multiple tags to improve random access

memory locations

and concatenation of requests per SCSI channel

32 KB, 64 KB, or 128 KB.

definable priority

RAID Management

RAID management is provided by software utilities that manage and
configure the RAID system and PERC 3/SC, create and manage multiple
disk arrays, control and monitor multiple RAID servers, provide error
statistics logging, and provide online maintenance. They include:

• PERC 3 BIOS Configuration utility (Ctrl-M)

•Dell Manager

• WebBIOS Configuration Utility

• Dell™ OpenManage™ Array Manager

PERC 3 BIOS Configuration Utility

You can use the PERC 3 BIOS Configuration Utility to configure and
maintain RAID arrays, format disk drives, and manage the RAID system. It
is independent of any operating system. See Chapter 11 "PERC 3 BIOS
Configuration Utility" for additional information.

PERC 3/SC Features 61

Dell Manager

Dell Manager is a character-based, non-GUI utility that changes policies
and parameters, and monitors RAID systems. Dell Manager runs under
Novell NetWare 5.x, 6.x, and Red Hat Linux 7.x. See Chapter 12 "Dell
Manager" for additional information.

WebBIOS Configuration Utility

WebBIOS is used to configure and manage a RAID system using an HTML
interface. See the WebBIOS Configuration Utility Guide for more
information.

www.dell.com | support.dell.com

Dell OpenManage Array Manager

Dell OpenManage Array Manager is used to configure and manage a storage
system that is connected to a server, while the server is active and continues
to handle requests. Array Manager runs under NetWare, Windows NT, and
Windows 2000. Refer to Dell documentation on the Dell web site at

support.dell.com

for more information.

62 PERC 3/SC Features

SECTION 5

PERC 3/DC and PERC
3/DCL Features

Hardware Requirements

Configuration Features

Hardware Architecture Features

Array Performance Features

Fault Tolerance Features

Software Utilities

Operating System Software Drivers

PERC 3/DC and PERC 3/DCL Specifications

Hardware Requirements

NOTE: The PERC 3/DC

has a battery option,
while the PERC 3/DCL
does not have a battery
option.

www.dell.com | support.dell.com

PERC 3/DC and PERC 3/DCL have two SCSI channels that support 160M
and Wide SCSI at data transfer rates up to 160 MB/s. The SCSI channel
supports up to 15 Wide devices or up to seven narrow devices.

PERC 3/DC and PERC 3/DCL can be installed in a system with a
motherboard that has 5 V, 32- or 64-bit PCI expansion slots. The system
should have an Intel

®

Pentium® II or higher central processing unit (CPU),
a diskette drive, a color monitor, video graphics adapter (VGA) card, and a
keyboard. A mouse is recommended.

Configuration Features

The PERC 3/DC and PERC 3/DCL configuration features are shown in
Tab l e 5 -1 .

Table 5-1. Configuration Features

Specification Feature

RAID levels 0, 1, 5, 10, and 50

SCSI channels 2

Maximum number of drives per channel 15

Array interface to host PCI 2.2

Drive interface Wide 160M

Cache memory size 64 MB (PERC 3/DCL)

128 MB DIMM (PERC 3/DC)

Cache function Write-back, write-through, adaptive

read-ahead, non read-ahead, read­ahead

Multiple logical drives/arrays per
controller

Maximum number of PERC 3/DC and
PERC 3/DCL controllers per system

Online capacity expansion Yes

Dedicated and pool hot spare Yes

Up to 40 logical drives per controller

Contact your Dell™ representative.

64 PERC 3/DC and PERC 3/DCL Features

Table 5-1. Configuration Features

Specification Feature

Flashable firmware Yes

Hot swap devices supported Yes

Non-disk devices supported No

Mixed capacity hard disk drives Yes

Number of 16-bit internal connectors 2

Cluster support Yes (PERC 3/DC only)

(continued)

SMART Technology

The PERC 3/DC and PERC 3/DCL self-monitoring analysis and reporting
technology (SMART) detects predictable drive failures. SMART monitors
the internal performance of all motors, heads, and drive electronics.

Configuration on Disk

Configuration on Disk (drive roaming) saves configuration information
both in NVRAM on PERC 3/DC and PERC 3/DCL and on the disk drives
attached to PERC 3/DC and PERC 3/DCL. If PERC 3/DC and PERC
3/DCL are replaced, the new PERC 3/DC and PERC 3/DCL controllers
detect the actual RAID configuration, maintaining the integrity of the data
on each drive, even if the drives have changed channel and/or target ID.

Drive roaming is supported across channels on the same controller. Drive
roaming across channels is not supported when cluster mode is enabled.
Table 5-2 shows the features for Configuration on Disk.

Table 5-2. Configuration on Disk Features

Specification Feature

Support for hard disk drives with capacities of more
than 8 gigabytes (GB)

Online RAID level migration Yes

RAID remapping Yes

No reboot necessary after expansion Yes (Only if virtual sizing

Ye s

is enabled.)

NOTE: Configuration on

Disk does not work if you
change both the adapter,
and the SCSI connectors
to different connectors on
the new adapter. It works
only if you make one
change at a time.

PERC 3/DC and PERC 3/DCL Features 65

Table 5-2. Configuration on Disk Features

Specification Feature

More than 200 qtags per array Yes

Hardware clustering support on the board Yes

User-specified rebuild rate Yes

(continued)

Hardware Architecture Features

Table 5-3 displays the PERC 3/DC and PERC 3/DCL hardware architecture

www.dell.com | support.dell.com

features.

Table 5-3. Hardware Architecture Features

Specification Feature

Processor Intel i960RN 100MHz

SCSI controller(s) One QLogic

controller

Size of flash ROM 1 MB

Amount of non-volatile random access
memory (NVRAM)

Hardware-exclusive OR (XOR)
assistance

Direct input/output (I/O) Yes

SCSI bus termination Active, single-ended or low voltage

Double-sided dual in-line memory
modules (DIMMs)

Auxiliary TermPWR source No

Direct I/O bandwidth 533 MB/s (greater than 200 MB/s

32 KB

Ye s

differential (LVD)

Ye s

sustained)

®

12160 Dual SCSI

66 PERC 3/DC and PERC 3/DCL Features

Array Performance Features

Table 5-4 displays the PERC 3/DC and PERC 3/DCL array performance
features.

Table 5-4. Array Performance Features

Specification Feature

Host data transfer rate 533 MB/s

Drive data transfer rate 160 MB/s

Maximum scatter/gathers 26 elements

Maximum size of I/O requests 6.4 MB in 64 KB stripes

Maximum queue tags per drive As many as the drive can accept.

Stripe sizes 2 KB, 4 KB, 8 KB, 16 KB, 32 KB,

64 KB, or 128 KB

Maximum number of concurrent
commands

Support for multiple initiations Yes

255

Fault Tolerance Features

Table 5-5 lists the fault tolerance features.

Table 5-5. Fault Tolerance Features

Specification Feature

Support for SMART Yes

Optional battery backup for cache memory Yes. Up to 72 hours data

retention.

Drive failure detection Automatic

Drive rebuild using hot spares Automatic

Manual replacement of hard drives without system
shutdown

Parity generation and checking Yes

Ye s

PERC 3/DC and PERC 3/DCL Features 67

Software Utilities

Table 5-6 lists the software utilities.

Table 5-6. Software Utilities

Specification Feature

Graphical user interface (GUI) Yes

Management utility Yes

Bootup configuration using BIOS Configuration Utility
(Ctrl–M)

www.dell.com | support.dell.com

Online read, write, and cache policy switching Yes

Intranet support Yes

Ye s

Operating System Software Drivers

PERC 3/DC and PERC 3/DCL include a Disk Operating System (DOS)
software configuration utility and drivers for Microsoft
V4.0, Windows

®

2000, Novell® NetWare® 5.x, 6.x, and Red Hat Linux 7.x.

®

Windows NT®

PERC 3/DC and PERC 3/DCL
Specifications

Table 5-7 lists the PERC 3/DC and PERC 3/DCL specifications.

Table 5-7. PERC 3/DC and PERC 3/DCL Specifications

Parameter Specification

Card size Half-length PCI card size (6.875" X 4.2").

Processor Intel i960RN™ 64-bit RISC processor @ 100 MHz

Bus type PCI 2.2

PCI controller Intel i960RN

Bus data transfer rate Up to 533 MB/s at 64/66 MHz

Basic input/output system
(BIOS)

PERC 3/DC and PERC 3/DCL BIOS

68 PERC 3/DC and PERC 3/DCL Features

Table 5-7. PERC 3/DC and PERC 3/DCL Specifications

Parameter Specification

Cache configuration 64 MB or 128 MB DIMM

Firmware 1 MB × 8 flash ROM

Nonvolatile random access
memory (RAM)

Operating voltage 5 V, 3.3 V

SCSI controller Two SCSI controllers for 160M and Wide support.

SCSI data transfer rate Up to 160 MB/s per channel

SCSI bus LVD or single-ended

SCSI termination Active

Termination disable Automatic through cable and device detection

Devices per SCSI channel Up to 15 wide or seven narrow SCSI devices.

SCSI device types Synchronous or asynchronous.

RAID levels supported 0, 1, 5, 10, and 50

SCSI connectors Two 68-pin internal high-density connectors for 16-

Serial port 3-pin RS232C-compatible connector (for

32 KB × 8 for storing RAID configuration

bit SCSI devices. Two ultra-high density 68-pin
external connectors for 160M and Wide SCSI.

manufacturing use only)

PCI Bridge/CPU

Both PERC 3/DC and PERC 3/DCL use the Intel i960RN PCI bridge with
an embedded i960RN RISC processor running at 100 MHz. The RN bridge
handles data transfers between the primary (host) PCI bus, the secondary
PCI bus, cache memory, and the SCSI bus. The DMA controller supports
chaining and unaligned data transfers. The embedded i960JN CPU directs
all controller functions, including command processing, SCSI bus transfers,
RAID processing, drive rebuilding, cache management, and error recovery.

PERC 3/DC and PERC 3/DCL Features 69

Cache Memory

Either 64 MB or 128 MB of PERC 3/DC and PERC 3/DCL cache memory
reside in a memory bank that uses a 64 MB or 128 MB SDRAM DIMM.
PERC 3/DC and PERC 3/DCL support write-through or write-back
caching, selectable for each logical drive. To improve performance in
sequential disk accesses, the PERC 3/DC and PERC 3/DCL controllers use
read-ahead caching by default. You can disable read-ahead caching.

PERC 3/DC and PERC 3/DCL BIOS

The BIOS resides on a 1 MB × 8 flash ROM for easy upgrade. The PERC

www.dell.com | support.dell.com

3/DC and PERC 3/DCL BIOS supports INT 13h calls to boot DOS without
special software or device drivers. The PERC 3/DC and PERC 3/DCL BIOS
provides an extensive setup utility that can be accessed by pressing <Ctrl>
<M> at BIOS initialization. PERC 3/DC and PERC 3/DCL BIOS
Configuration utility is described in Chapter 11 "PERC 3 BIOS
Configuration Utility."

Onboard Speaker

The PERC 3/DC and PERC 3/DCL controller has an onboard tone
generator for audible warnings when system errors occur. Audible warnings
can be generated through this speaker. The audible warnings are listed in
Chapter 13 "Troubleshooting."

Serial Port

PERC 3/DC and PERC 3/DCL includes a 3-pin RS232C-compatible serial
port connector. This is for manufacturing use only.

SCSI Bus

The PERC 3/DC and PERC 3/DCL controller has four Wide 160M SCSI
channels that support both LVD and single-ended devices with active
termination. Synchronous and asynchronous devices are supported. PERC
3/DC and PERC 3/DCL provides automatic termination disable via cable
detection. The SCSI channel supports up to 15 wide or seven non-wide
SCSI devices at speeds up to 160 MB/s.

70 PERC 3/DC and PERC 3/DCL Features

SCSI Connectors

The PERC 3/DC and PERC 3/DCL adapter has two types of SCSI
connectors:

• Two 68-pin high density internal connectors

• Two 68-pin external ultra-high-density connectors

Only one connector type can be used for the SCSI channel at any one time.

SCSI Termination

PERC 3/DC and PERC 3/DCL uses active termination on the SCSI bus
conforming to SCSI-2 and SCSI-3 specifications. Termination
enable/disable is automatic through cable detection.

SCSI Firmware

The PERC 3/DC and PERC 3/DCL firmware handles all RAID and SCSI
command processing and supports the feature listed in Table 5-8.

Table 5-8. SCSI Firmware

Feature Description

Disconnect/
reconnect

Tagged command
queuing

Scatter/gather A single command can transfer data to and from different

Multi-threading Up to 255 simultaneous commands with elevator sorting

Stripe size Variable for all logical drives: 2 KB, 4 KB, 8 KB, 16 KB,

Rebuild Multiple rebuilds and consistency checks with user-

Optimizes SCSI bus seek.

Multiple tags to improve random access

memory locations.

and concatenation of requests per SCSI channel

32 KB, 64 KB, or 128 KB

definable priority

PERC 3/DC and PERC 3/DCL Features 71

RAID Management

RAID management is provided by software utilities that manage and
configure the RAID system and PERC 3/DC and PERC 3/DCL, create and
manage multiple disk arrays, control and monitor multiple RAID servers,
provide error statistics logging, and provide online maintenance. The
utilities are:

• PERC 3 BIOS Configuration utility (Ctrl-M)

•Dell Manager

• WebBIOS Configuration Utility

www.dell.com | support.dell.com

• Dell OpenManage™ Array Manager

PERC 3 BIOS Configuration Utility

You can use the PERC 3 BIOS Configuration Utility to configure and
maintain RAID arrays, format disk drives, and manage the RAID system. It
is independent of any operating system. See Chapter 11 "PERC 3 BIOS
Configuration Utility" for additional information.

Dell Manager

Dell Manager is a character-based, non-GUI utility that changes policies,
and parameters, and monitors RAID systems. Dell Manager runs under
Novell NetWare 5.x, 6.x, and Red Hat Linux 7.x. See Chapter 12 "Dell
Manager" for additional information.

WebBIOS Configuration Utility

WebBIOS is used to configure and manage a RAID system using an HTML
interface. See the WebBIOS Configuration Utility Guide for more
information.

Dell OpenManage Array Manager

Dell OpenManage Array Manager is used to configure and manage a storage
system that is connected to a server, while the server is active and continues
to handle requests. Array Manager runs under NetWare, Windows NT, and
Windows 2000. Refer to Dell documentation on the Dell web site at

support.dell.com

for more information.

72 PERC 3/DC and PERC 3/DCL Features

SECTION 6

PERC 3/QC Features

Hardware Requirements

Configuration Features

Hardware Architecture Features

Array Performance Features

Fault Tolerance Features

Software Utilities

Operating System Software Drivers

PERC 3/QC Specifications

Hardware Requirements

PERC 3/QC is a high-performance intelligent peripheral component
interconnect (PCI)-to-SCSI host adapter with RAID control capabilities.
PERC 3/QC has four SCSI channels that support 160M and Wide SCSI at
data transfer rates up to 160 MB/s. Each SCSI channel supports up to 15
Wide devices or up to seven narrow devices.

PERC 3/QC can be installed in a system with a motherboard that has 5 V,

®

32- or 64-bit PCI expansion slots. The system should have an Intel

®

Pentium

II or higher central processing unit (CPU), a diskette drive, a

color monitor, video graphics adapter (VGA) card, and a keyboard. A mouse

www.dell.com | support.dell.com

is recommended.

Configuration Features

Table 6-1 lists the PERC 3/QC configuration features.

Table 6-1. Configuration Features

Specification Feature

RAID levels 0, 1, 5, 10, and 50

SCSI channels 4

Maximum number of drives per channel 15

Array interface to host PCI 2.2

Drive interface Wide 160M

Cache memory size 128 MB DIMM

Cache function Write-back, write-through, adaptive

read-ahead, non read-ahead, read­ahead

Multiple logical drives/arrays per
controller

Maximum number of PERC 3/QC
controllers per system

Online capacity expansion Yes

Dedicated and pool hot spare Yes

Flashable firmware Yes

Up to 40 logical drives per controller

Contact your Dell™ representative.

74 PERC 3/QC Features

Table 6-1. Configuration Features

Specification Feature

Hot swap devices supported Yes

Non-disk devices supported No

Mixed-capacity hard drives Yes

Number of 16-bit internal connectors 2

(continued)

SMART Technology

The PERC 3/QC self-monitoring analysis and reporting technology
(SMART) detects predictable drive failures. SMART monitors the internal
performance of all motors, heads, and drive electronics.

Configuration on Disk

Configuration on Disk (drive roaming) saves configuration information
both in non-volatile random access memory (NVRAM) on PERC 3/QC and
on the disk drives attached to PERC 3/QC. If PERC 3/QC is replaced, the
new PERC 3/QC controller detects the actual RAID configuration,
maintaining the integrity of the data on each drive, even if the drives have
changed channel and/or target ID.

Drive roaming is supported across channels on the same controller. Drive
roaming across channels is not supported when cluster mode is enabled.
Table 6-2 lists the Configuration on Disk features.

Table 6-2. Configuration on Disk Features

Specification Feature

Support for hard drives with capacities of more
than 8 gigabytes (GB)

Online RAID level migration Yes

RAID remapping Yes

No reboot necessary after expansion Yes (only if virtual sizing is

More than 200 qtags per array Yes

Hardware clustering support on the board Yes

Ye s

enabled)

NOTE: The PERC 3/QC

does not support
clustering.

NOTE: Configuration on

Disk does not work if you
change both the adapter,
and the SCSI connectors
to different connectors on
the new adapter. It works
only if you make one
change at a time.

PERC 3/QC Features 75

Table 6-2. Configuration on Disk Features

Specification Feature

User-specified rebuild rate Yes

(continued)

Hardware Architecture Features

Table 6-3 lists the PERC 3/QC hardware architecture features.

Table 6-3. Hardware Architecture Features

www.dell.com | support.dell.com

Specification Feature

Processor Intel i960RN 100MHz

SCSI controller(s) Two QLogic

controller

Size of flash ROM 1 MB

Amount of NVRAM 32 KB

Hardware exclusive OR (XOR)
assistance

Direct input/output (I/O) Yes

SCSI bus termination Active, single-ended or low-voltage

Double-sided dual in-line memory
modules (DIMMs)

Auxiliary TermPWR source No

Direct I/O bandwidth 533 MB/s (greater than 200 MB/s

Ye s

differential (LVD)

Ye s

sustained)

®

12160 dual SCSI

Array Performance Features

Table 6-4 lists the array performance features.

76 PERC 3/QC Features

Table 6-4. Array Performance Features

Specification Feature

Host data transfer rate 533 MB/s

Table 6-4. Array Performance Features

Specification Feature

Drive data transfer rate 160 MB/s

Maximum scatter/gathers 26 elements

Maximum size of I/O requests 6.4 MB in 64 KB stripes

Maximum queue tags per drive As many as the drive can accept.

Stripe sizes 2 KB, 4 KB, 8 KB, 16 KB, 32 KB,

Maximum number of concurrent
commands

Support for multiple initiations Yes

(continued)

64 KB, or 128 KB

255

Fault Tolerance Features

The fault tolerance features are listed in Table 6-5.

Table 6-5. Fault Tolerance Features

Specification Feature

Support for SMART Yes

Optional battery backup for cache memory Yes. Up to 72 hours data

retention.

Drive failure detection Automatic

Drive rebuild using hot spares Automatic

Manual replacement of drives without system
shutdown

Parity generation and checking Yes

Ye s

Software Utilities

The software utilities are listed in Table 6-6.

PERC 3/QC Features 77

Table 6-6. Software Utilities

Specification Feature

Graphical user interface Yes

Management utility Yes

Bootup configuration using PERC BIOS configuration
utility (Ctrl–M)

Online read, write, and cache policy switching Yes

Intranet support Yes

www.dell.com | support.dell.com

Ye s

Operating System Software Drivers

PERC 3/QC includes a DOS software configuration utility and drivers for
Microsoft

®

Windows NT® 4.0, Windows® 2000, Novell® NetWare® and

Red Hat Linux.

PERC 3/QC Specifications

The PERC 3/QC specifications are listed in Table 6-7.

Table 6-7. PERC 3/QC Specifications

Parameter Specification

Card size 12.3" x 4.2" (full length PCI)

Processor Intel i960RN™ 64-bit RISC processor @ 100

MHz

Bus type PCI 2.2

PCI controller Intel i960RN

Bus data transfer rate Up to 533 MB/s at 64/66 MHz

Basic input/output system
(BIOS)

Cache configuration 64 MB or 128 MB DIMM

Firmware 1 MB × 8 flash ROM

Non-volatile random access
memory (RAM)

PERC 3/QC BIOS

32 KB × 8 for storing RAID configuration

78 PERC 3/QC Features

Table 6-7. PERC 3/QC Specifications

Parameter Specification

Operating voltage 5 V, 3.3 V

SCSI controller Four SCSI controllers for 160M and Wide

support.

SCSI data transfer rate Up to 160 MB/s per channel

SCSI bus LVD or single-ended

SCSI termination Active

Termination disable Automatic through cable and device detection

Devices per SCSI channel Up to 15 wide or seven narrow SCSI devices.

SCSI device types Synchronous or asynchronous.

RAID levels supported 0, 1, 5, 10, and 50

SCSI connectors Two 68-pin internal high-density connectors for

16-bit SCSI devices. Four ultra-high density 68­pin external connectors for 160M and Wide
SCSI.

Serial port 9-pin RS232C-compatible connector (for

manufacturing use only)

(continued)

PCI Bridge/CPU

PERC 3/QC uses the Intel i960RN PCI bridge with an embedded i960RN
RISC processor running at 100 MHz. The RN bridge handles data transfers
between the primary (host) PCI bus, the secondary PCI bus, cache memory,
and the SCSI bus. The DMA controller supports chaining and unaligned
data transfers. The embedded i960JN CPU directs all controller functions,
including command processing, SCSI bus transfers, RAID processing, drive
rebuilding, cache management, and error recovery.

Cache Memory

128 MB of PERC 3/QC cache memory resides in a memory bank that uses a
64 MB or 128 MB SDRAM DIMM. PERC 3/QC supports write-through or
write-back caching, selectable for each logical drive. To improve
performance in sequential disk accesses, the PERC 3/QC controller uses
read-ahead caching by default. You can disable read-ahead caching.

PERC 3/QC Features 79

PERC 3/QC BIOS

The BIOS resides on a 1 MB × 8 flash ROM for easy upgrade. The PERC
3/QC BIOS supports INT 13h calls to boot DOS without special software or
device drivers. The PERC 3/QC BIOS provides an extensive setup utility
that can be accessed by pressing <Ctrl> <M> at BIOS initialization.
PERC 3 BIOS Configuration Utility is described in Chapter 11
"Troubleshooting."

Onboard Speaker

The PERC 3/QC controller has an onboard tone generator for audible

www.dell.com | support.dell.com

warnings when system errors occur. Audible warnings can be generated
through this speaker. The audible warnings are listed in Chapter 13.

Serial Port

PERC 3/QC includes a 9-pin RS232C-compatible serial port connector.
This is for manufacturing use only.

SCSI Bus

PERC 3/QC has four Wide 160M SCSI channels that support both LVD
and single-ended devices with active termination. Synchronous and
asynchronous devices are supported. PERC 3/QC provides automatic
termination disable by using cable detection. The SCSI channel supports
up to 15 wide or seven non-wide SCSI devices at speeds up to 160 MB/s.

80 PERC 3/QC Features

SCSI Connectors

PERC 3/QC has two types of SCSI connectors:

• Two 68-pin high density internal connectors

• Four 68-pin external ultra-high-density connectors

Only one connector type can be used for the SCSI channel at any one time.

SCSI Termination

PERC 3/QC uses active termination on the SCSI bus conforming to SCSI-2
and SCSI-3 specifications. Termination enable/disable is automatic through
cable detection.

SCSI Firmware

The PERC 3/QC firmware handles all RAID and SCSI command
processing and supports the features described in Table 6-8.

Table 6-8. SCSI Firmware

Feature Description

Disconnect/
reconnect

Tagged command
queuing

Scatter/gather A single command can transfer data to and from different

Multi-threading Up to 255 simultaneous commands with elevator sorting

Stripe size Variable for all logical drives: 2 KB, 4 KB, 8 KB, 16 KB,

Rebuild Multiple rebuilds and consistency checks with user-

Optimizes SCSI bus utilization

Multiple tags to improve random access

memory locations.

and concatenation of requests per SCSI channel

32 KB, 64 KB, or 128 KB.

definable priority

RAID Management

RAID management is provided by software utilities that manage and
configure the RAID system and PERC 3/QC, create and manage multiple
disk arrays, control and monitor multiple RAID servers, provide error
statistics logging, and provide online maintenance. They include:

• PERC 3/QC BIOS Configuration Utility (Ctrl-M)

•Dell Manager

• WebBIOS Configuration Utility

• Dell™ OpenManage™ Array Manager

PERC 3 BIOS Configuration Utility

You can use the PERC 3 BIOS Configuration Utility to configure and
maintain RAID arrays, format disk drives, and manage the RAID system. It
is independent of any operating system. See Chapter 11 "PERC 3 BIOS
Configuration Utility" for additional information.

PERC 3/QC Features 81

Dell Manager

Dell Manager is a character-based, non-GUI utility that changes policies,
and parameters, and monitors RAID systems. Dell Manager runs under
Novell NetWare 5.x, 6.x, and Red Hat Linux 7.x. See Chapter 12 "Dell
Manager" for additional information.

WebBIOS Configuration Utility

WebBIOS is used to configure and manage a RAID system using an HTML
interface. See the WebBIOS Configuration Utility Guide for more
information.

www.dell.com | support.dell.com

Dell OpenManage™ Array Manager

Dell OpenManage Array Manager is used to configure and manage a storage
system that is connected to a server, while the server is active and continues
to handle requests. Array Manager runs under NetWare, Windows NT, and
Windows 2000. Refer to Dell documentation on the Dell web site at

support.dell.com

for more information.

82 PERC 3/QC Features

SECTION 7

Configuring PERC 3

Configuring SCSI Physical Drives

Current Configuration

Logical Drive Configuration

Physical Device Layout

Configuring Arrays

Configuration Strategies

Assigning RAID Levels

Configuring Logical Drives

Optimizing Data Storage

Planning the Array Configuration

Random Array Deletion

Configuring SCSI Physical Drives

Physical SCSI drives must be organized into logical drives. The arrays and
logical drives that you construct must be able to support the RAID) level
that you select.

Observe the following guidelines when connecting and configuring SCSI
devices in a RAID array:

• You can place up to 32 physical disk drives in an array.

• Include all drives that have the same capacity in the same array. If the
drives are not the same size, the array uses the size of the smallest drive

www.dell.com | support.dell.com

and the same amount of space on the other drives to construct the
arrays.

• Make sure any hot spare has a capacity that is at least as large as the
largest drive that may be replaced by the hot spare.

• When replacing a failed drive, make sure that the replacement drive
has a capacity that is at least as large as the drive being replaced.

Current Configuration

Your PERC 3 card has one (SC), two (DC, DCL), or four channels (QC),
depending on which card you have. Use Table 7-1 to list the devices that
you assign to each SCSI ID for SCSI Channel 0.

84 Configuring PERC 3

Table 7-1. Current Configuration for SCSI
Channel 0

SCSI ID Device Description

SCSI Channel 0

0

1

2

3

4

5

6

Table 7-1. Current Configuration for SCSI
Channel 0

SCSI ID Device Description

8

9

10

11

12

13

14

15

(continued)

SCSI Channel 0

Use Table 7-2 to list the devices that you assign to each SCSI ID for SCSI
Channel 1.

Table 7-2. Current Configuration for SCSI
Channel 1

SCSI ID Device Description

SCSI Channel 1

0

1

2

3

4

5

6

8

9

10

11

12

Configuring PERC 3 85

Table 7-2. Current Configuration for SCSI
Channel 1

SCSI ID Device Description

13

14

15

(continued)

SCSI Channel 1

Use Table 7-3 to list the devices that you assign to each SCSI ID for SCSI
Channel 2.

www.dell.com | support.dell.com

Table 7-3. Current Configuration for SCSI
Channel 2

SCSI ID Device Description

SCSI Channel 2

0

1

2

3

4

5

6

8

9

10

11

12

13

14

15

86 Configuring PERC 3

Use Table 7-4 to list the devices that you assign to each SCSI ID for SCSI
Channel 3.

Table 7-4. Current Configuration for SCSI
Channel 3

SCSI ID Device Description

SCSI Channel 3

0

1

2

3

4

5

6

8

9

10

11

12

13

14

15

Logical Drive Configuration

Use Table 7-5 to list the details for each logical drive that you configure.

Table 7-5. Logical Drive Configuration

Logical
Drive

LD0

LD1

RAID Stripe

Size

Logical
Drive Size

Cache
Policy

Read
Policy

Write
Policy

Configuring PERC 3 87

# of Physical
Drives

Logical
Drive

RAID Stripe

Size

Logical
Drive Size

Cache
Policy

Read
Policy

Write
Policy

# of Physical
Drives

LD2

LD3

LD4

LD5

LD6

LD7

LD8

www.dell.com | support.dell.com

LD9

LD10

LD11

LD12

LD13

LD14

LD15

LD16

LD17

LD18

LD19

LD20

LD21

LD22

LD23

LD24

LD25

LD26

LD27

LD28

LD29

LD30

88 Configuring PERC 3

Logical
Drive

LD31

LD32

LD33

LD34

LD35

LD36

LD37

LD38

LD39

RAID Stripe

Size

Logical
Drive Size

Cache
Policy

Read
Policy

Physical Device Layout

Use Table 7-6 to list the details for each physical device on the channels.

Table 7-6. Physical Device Layout

Channel 0 Channel 1 Channel 2 Channel 3

Targ et ID

Device type

Logical drive number/
Drive number

Manufacturer/Model
number

Firmware level

Targ et ID

Device type

Logical drive number/
Drive number

Manufacturer/Model
number

Firmware level

Targ et ID

Write
Policy

# of Physical
Drives

Configuring PERC 3 89

Table 7-6. Physical Device Layout

(continued)

Channel 0 Channel 1 Channel 2 Channel 3

Device type

Logical drive number/
Drive number

Manufacturer/Model
number

Firmware level

Targ et ID

www.dell.com | support.dell.com

Device type

Logical drive number/
Drive number

Manufacturer/Model
number

Firmware level

Targ et ID

Device type

Logical drive number/
Drive number

Manufacturer/Model
number

Firmware level

Targ et ID

Device type

Logical drive number/
Drive number

Manufacturer/Model
number

Firmware level

Targ et ID

Device type

Logical drive number/
Drive number

90 Configuring PERC 3

Table 7-6. Physical Device Layout

Channel 0 Channel 1 Channel 2 Channel 3

Manufacturer/Model
number

Firmware level

Targ et ID

Device type

Logical drive number/
Drive number

Manufacturer/Model
number

Firmware level

Targ et ID

Device type

Logical drive number/
Drive number

Manufacturer/Model
number

Firmware level

Targ et ID

Device type

Logical drive number/
Drive number

Manufacturer/Model
number

Firmware level

Targ et ID

Device type

Logical drive number/
Drive number

Manufacturer/Model
number

Firmware level

Targ et ID

(continued)

Configuring PERC 3 91

Table 7-6. Physical Device Layout

Channel 0 Channel 1 Channel 2 Channel 3

Device type

Logical drive number/
Drive number

Manufacturer/Model
number

Firmware level

Targ et ID

www.dell.com | support.dell.com

Device type

Logical drive number/
Drive number

Manufacturer/Model
number

Firmware level

Targ et ID

Device type

Logical drive number/
Drive number

Manufacturer/Model
number

Firmware level

(continued)

92 Configuring PERC 3

Configuring Arrays

Connect the physical drives to the RAID controller, configure the disks,
then initialize them. PERC 3 supports up to 40 arrays. An array is a group of
physical disk drives. An array can consist of one to 32 physical disk drives
(256 drives when used with the span feature in a RAID 50 configuration).
The number of drives in an array determines the RAID levels that can be
supported. The maximum number of drives that can be used is 60,
consisting of four channels with 15 drives each. PERC 3 supports up to 40
logical drives per controller.

Arranging Arrays

You must arrange the arrays to provide additional organization for the drive
array. You must arrange arrays so that you can create system drives that can
function as boot devices.

You can sequentially arrange arrays with an identical number of drives so
that the drives in the group are spanned. Spanned drives can be treated as
one large drive. Data can be striped across multiple arrays as one logical
drive.

You can create spanned drives using the PERC 3 BIOS Configuration
Utility.

Creating Hot Spares

Any drive that is present, formatted, and initialized but is not included in
an array or logical drive can be designated as a hot spare.

You can designate drives as hot spares using the PERC 3 BIOS
Configuration Utility.

Creating Logical Drives

Logical drives are arrays or spanned arrays that are presented to the
operating system. You must create one or more logical drives. The logical
drive capacity must include all of the disk space in an array. If an array with
drives with mixed sizes, the smallest common size is used and larger disk
drives are truncated. The logical drive capacity can also be larger than an
array by using spanning. PERC 3 supports up to 40 logical drives.

Configuration Strategies

The most important factors in RAID array configuration are:

• Drive capacity

• Drive availability (fault tolerance)

• Drive performance

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 the other two.

Configuring PERC 3 93

Maximizing Capacity

RAID 0 achieves maximum drive capacity, but does not provide data
redundancy. Maximum drive capacity for each RAID level is shown below.
original equipment manufacturer (OEM) level firmware that can span up to
four logical drives is assumed. Table 7-7 displays the drives required, and
capacity for the various RAID levels.

Table 7-7. Drives and Capacities for Each RAID Level

RAID
Level

www.dell.com | support.dell.com

0 Striping without

1 Mirroring 2 (Capacity of smallest disk) X (1)

5 Striping with

10 RAID 1 and

50 RAID 5 and

Description Drives

Required

1 – 32 (Number of disks) X (capacity of

parity

3 – 32 (Number of disks) X (capacity of
floating parity
drive

4 – 16
striping

striping

(Must be a

multiple of

2)

6 – 256

(Must be a

multiple of

arrays)

Capacity

smallest disk)

smallest disk) - (capacity of 1
disk)

(Number of disks) X (capacity of
smallest disk) / (2)

(Number of disks) X (capacity of
smallest disk) – (capacity of 1
disk X number of arrays)

Maximizing Drive Availability

You can maximize the availability of data on the physical disk drive in the
logical array by maximizing the level of fault tolerance. The levels of fault
tolerance provided by the RAID levels are shown in Table 7-8.

Table 7-8. Fault Tolerance Features for RAID Levels 0, 1
and 5

94 Configuring PERC 3

RAID
Level

0 No fault tolerance

1 Disk mirroring, which provides 100% data redundancy.

Fault Tolerance Protection

Table 7-8. Fault Tolerance Features for RAID Levels 0, 1
and 5

(continued)

RAID
Level

5 100% protection through striping and parity. The data is striped and

Fault Tolerance Protection

parity data is written across a number of physical disk drives.

Maximizing Drive Performance

You can configure an array for optimal performance; however, optimal drive
configuration for one type of application will probably not be optimal for
any other application. A basic guideline of the performance characteristics
for RAID drive arrays at each RAID level is shown in Table 7-9.

Table 7-9. Performance Characteristics for Each RAID
Level

RAID
Level

0 Excellent for all types of input/output (I/O) activity, but provides no

1 Provides data redundancy and good performance.

5 Provides data redundancy and good performance in most

10 Provides high data transfers and complete data redundancy.

50 Provides high data transfers and data redundancy.

Performance Characteristics

data security.

environments.

Assigning RAID Levels

Only one RAID level can be assigned to each logical drive. The drives
required per RAID level shown in Table 7-10.

Table 7-10. Physical Drives Required for Each RAID Level

RAID
Level

01 32

12 2

Minimum Number of
Physical Drives

Maximum Number of Physical
Drives

Configuring PERC 3 95

Table 7-10. Physical Drives Required for Each RAID Level

RAID
Level

53 32

10 4 16

50 6 256

www.dell.com | support.dell.com

Configuring Logical Drives

Minimum Number of
Physical Drives

Maximum Number of Physical
Drives

(PERC has a limit of 60, using
PERC 4/QC with 15 drives on each
of the 4 channels.)

After you have installed the PERC 3 controller in the server and have
attached all physical disk drives, perform the following steps to prepare a
RAID disk array:

1 Optimize the PERC 3 controller options for your system.

2 Press <Ctrl> <M> to run the BIOS Configuration Utility.

3 Define and configure one or more logical drives.

4 Select Easy Configuration in the PERC 3 BIOS Configuration Utility

or select New Configuration to customize the RAID array.

5 Create and configure one or more system drives (logical drives).

96 Configuring PERC 3

6 Select the RAID level, cache policy, read policy, and write policy.

7 Save the configuration.

8 Initialize the system drives.

After initialization, you can install the operating system.

Optimizing Data Storage

Data Access Requirements

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.

Array Functions

You must first define the major purpose of the disk array. Will this disk array
increase the system storage capacity for general-purpose file and print
servers? Does this disk array support any software system that must be
available 24 hours per day? Will the information stored in this disk array
contains large audio or video files that must be available on demand? Will
this disk array contain data from an imaging system?

You must identify the purpose of the data to be stored in the disk subsystem
before you can confidently choose a RAID level and a RAID configuration.

Planning the Array Configuration

Complete the items in Table 7-11 to help you plan the array configuration.

Table 7-11. Factors to Consider for Array Configuration

Question Answer

Number of physical disk drives in the array

Purpose of this array. Rank the following factors:

Maximize drive capacity

Maximize the safety of the data (fault tolerance)

Maximize hard drive performance and throughput

How many hot spares?

Amount of cache memory installed on PERC 3

Are all of the disk drives and the server protected by a UPS?

Configuring PERC 3 97

Using the Array Configuration Planner

Table 7-12 lists RAID levels, fault tolerance, and effective capacity for some
possible drive configurations for an array consisting of one to 32 drives. This
table does not take into account any hot spare (standby) drives. You should
always have a hot spare drive in case of drive failure. RAID 1 requires two
drives. RAID 5 requires at least three drives. RAID 10 requires at least four
drives. RAID 50 requires at least six drives.

Table 7-12. Array Configuration Planner

Number

www.dell.com | support.dell.com

of Drives

1 RAID 0 Excellent No 100%

2 RAID 0 Excellent No 100%

2 RAID 1 Good Yes 50%

3 RAID 0 Excellent No 100%

3 RAID 5 Good Yes 67%

4 RAID 0 Excellent No 100%

4 RAID 5 Good Yes 75%

4 RAID 10 Good Yes 50%

5 RAID 0 Excellent No 100%

5 RAID 5 Good Yes 80%

6 RAID 0 Excellent No 100%

6 RAID 5 Good Yes 83%

6RAID 10

6RAID 50

7 RAID 0 Excellent No 100%

7 RAID 5 Good Yes 86%

8 RAID 0 Excellent No 100%

8 RAID 5 Good Yes 87%

8RAID 10

Possible RAID
Levels

(spanned)

(spanned)

(spanned)

Relative
Performance

Excellent Yes 50%

Good Yes 67%

Excellent Yes 50%

Fau l t
Tol e r a nc e

Effective
Capacity

98 Configuring PERC 3