3Ware 720-0104-00 User manual

3ware®
Serial ATA RAID Controller
Command Line Interface
Supports the 9000 Series
PN: 720-0104-00
April, 2004
CLI Guide

Copyright
©2003-2004 3ware, Inc. All rights reserved. No part of this publication may
be reproduced, stored in a retrieval system, or transmitted in any form by any
means, electronic, mechanical, photocopying, recording or otherwise, without
the proper written consent of 3ware, Inc., 455 West Maude Ave., Sunnyvale,
CA 94085.
Trademarks
3ware, Escalade, and 3DM are all registered trademarks of 3ware, Inc. The
3ware logo, 3BM, StorSwitch, TwinStor, and R5 Fusion are all trademarks of
3ware, Inc. All other trademarks herein are property of their respective
owners.
Disclaimer
3ware, Inc. assumes no responsibility for errors or omissions in this
document, nor does 3ware, Inc. make any commitment to update the
information contained herein.

www.3ware.com i
About This Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
How this Guide is Organized . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Introduction to the 3ware Command Line Interface . . . . . . . . . . . . . . . 3
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Supported Operating Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Installing the 3ware CLI. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Installing 3ware CLI on Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Installing the 3ware CLI on Linux and FreeBSD . . . . . . . . . . . . . . . . . . . . . . . . . .5
Working with 3ware CLI. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Using the command interface interactively . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Using a single command with output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Using an input file to execute a script . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Understanding RAID Concepts and Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Available RAID Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Determining What RAID Level to Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
CLI Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Screen Reporting Style . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Info Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
info . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
info cid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
info cid driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
info cid model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
info cid firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
info cid bios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
info cid monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
info cid serial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
info cid pcb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
info cid pchip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
info cid achip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
info cid numports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
info cid numunits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
info cid numdrives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
info cid unitstatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
info cid allunitstatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
info cid drivestatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
info cid exportjbod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
info cid ondegrade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
info cid spinup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
info cid stagger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
info cid uid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
info cid uid status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
info cid uid rebuildstatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
info cid uid verifystatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
info cid uid initializestatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
info cid pid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Table of Contents

ii 3ware 9000 Series Serial ATA Controller CLI Guide
info cid pid status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
info cid pid model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
info cid pid serial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
info cid pid capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
info cid pid smart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
info cid diag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Maint Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
[maint] rescan [cid ...] [noscan] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
[maint] remove cid uid [noscan] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
[maint] remove cid pid [noscan] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
[maint] deleteunit cid uid [noscan] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
[maint] createunit cid rRAIDType pid_list [kStripe] [noscan] [Dsk_Grp] [nocache]
[autoverify] [ignoreECC] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
[maint] rebuild cid uid pid_list [ignoreECC] . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
[maint] rebuild cid uid pause . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
[maint] rebuild cid uid resume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
[maint] flush cid [uid ...] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
[maint] verify cid uid [stop] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
[maint] mediascan cid start|stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
[maint] commit cid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Sched Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
sched rebuild cid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
sched rebuild cid add day hour duration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
sched rebuild cid remove slot_id . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
sched rebuild cid enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
sched rebuild cid disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
sched verify cid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
sched verify cid add day hour duration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
sched verify cid remove slot_id . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
sched verify cid enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
sched verify cid disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
sched selftest cid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
sched selftest cid add day hour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
sched selftest cid remove slot_id . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
sched selftest cid enable selftest_task_id . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
sched selftest cid disable selftest_task_id . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
Alarms Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
alarms [cid ...] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
Set Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
set rebuild cid 1..5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
set verify cid 1..5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
set cache cid uid on|off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
set autoverify cid uid on|off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
set overwriteECC cid uid on|off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Help Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
help info . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
help alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
help set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
help maint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
help sched . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
help quit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
Return Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

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About This Guide
3ware 9000 Series Serial ATA Controller CLI Guide provides instructions for
configuring and maintaining your 3ware controller using 3ware’s command
line interface (CLI).
This guide assumes that you have already installed your controller in your
system. If you have not yet done so, see 3ware 9000 Series Serial ATA RAID
Controller Installation Guide for instructions.
How this Guide is Organized
There are often multiple ways to accomplish the same configuration and
maintenance tasks for your 3ware controller. While this manual includes
instructions for performing tasks using the command line interface, two
additional tools are available:
3ware BIOS Manager
3DM®2 (3ware Disk Manager)
For information about these tools, see 3ware 9000 Series Serial ATA RAID
Controller User Guide.
Table 1: Sections in this Guide
Section Description
Introduction to 3ware Command
Line Interface
Installation, Features, Concepts
Reference Describes Individual Commands

About This Guide
23ware 9000 Series Serial ATA Controller CLI Guide
Conventions
The following conventions are used through this guide:
■3BM refers to the 3ware BIOS Manager
■3DM refers to the 3ware Disk Manager, version 2.
■Monospace font is used for code and for things you type.
■In commands, an italic font indicates items that you must specify, such as
a controller ID, or a unit ID.
■In commands, brackets around an item indicates that it is optional.
■In commands, ellipses (. . .) indicate that more than one parameter can be
included.
■In commands, a brace (|) indicates an 'or' situation where the user has a
choice between more than one option, but only one can be specified.
Additional details are provided in “CLI Reference” on page 15.

www.3ware.com 3
Introduction to the 3ware
Command Line Interface
The 3ware SATA RAID Controller Command Line Interface (CLI) for Linux,
Windows, and FreeBSD is provided to manage 7000, 8000, and 9000-series
3ware ATA and Serial ATA RAID controllers. Multiple 3ware controllers can
be managed using the CLI via a command line or script. CLI is useful in
environments where a graphical user interface (GUI) is not available.
Note: All information contained in this document that describes
usage for the 3ware 9000 series products should not be used with
3ware 7000 or 8000 series controllers.
Warning!
For all of the functions of the 3ware CLI to work properly, you
must have the proper CLI, firmware, and driver versions installed.
Check www.3ware.com for the latest versions and upgrade instruc-
tions.
Features
3ware CLI is a command line interface storage management application for
3ware ATA RAID Controllers. It provides controller, logical unit, and drive
management. It can be used in both interactive and batch mode, providing
higher level API functionalities.
The 3ware CLI provides the functionality of the 3ware Disk Management
(3DM®2) utility through a command line interface. You can use it to view
unit status and version information and perform maintenance functions such

Introduction to the 3ware Command Line Interface
43ware 9000 Series Serial ATA Controller CLI Guide
as adding or removing drives. 3ware CLI also includes advanced features for
creating and deleting RAID units online.
Note: For complete information on 3DM 2 and for information
about configuring or upgrading your computer, refer to the 3ware
9000 Series Serial ATA RAID Controller User Guide.
Supported Operating Systems
■Windows. Windows 2000 with SP3 or newer, Windows XP with SP1 or
newer, and Windows Server 2003.
■Linux.Redhat, SuSE
■FreeBSD
Note: The 3ware CLI support for FreeBSD is currently a beta release.
Terminology
This document uses the following terminology:
Logical Units. Usually shortened to “units.” These are block devices
presented to operating systems. A logical unit can be a one-tier, two-tier, or
three-tier arrangement. JBOD, Spare, and Single logical units are examples of
one-tier units. RAID 1 and RAID 5 are examples of two-tier units and as such
will have sub-units. RAID 10 and RAID 50 are examples of three-tier units
and as such will have sub-sub-units.
Port. A controller has one or many ports (typically 4, 8, 12). Each port can be
attached to a single disk drive.
For additional information about 3ware controller concepts and terminology,
see 3ware 9000 Series Serial ATA RAID Controller User Guide.
Installing the 3ware CLI
Warning!
3ware does not recommend installing both 3DM 2 and CLI.
Conficts may ocur. For example, if both are installed, alarms will
be captured only by 3DM. You should use either CLI or 3DM 2 to
manage your 3ware RAID controllers..
For all of the functions of the 3ware CLI to work properly, you must have the
proper CLI, firmware, and driver versions installed. Check www.3ware.com
for the latest versions and upgrade instructions.

Installing the 3ware CLI
www.3ware.com 5
Installing 3ware CLI on Windows
3ware CLI can be run from the 3ware CD, or copied to your computer from
the 3ware software CD-ROM. You can also download the CLI from the 3ware
web site, www.3ware.com.
To install 3ware CLI on Windows, copy the file tw_cli.exe to the directory
from which you want to run the program. CLI is located on the 3ware CD in
the directory \packages\cli\windows
Note: CLI comes in both 32-bit and 64-bit versions. Be sure to copy the
correct version.
CLI can only be run by an administrator or a user with administrator rights.
Without the correct privileges, CLI will prompt and then exit when the
application is executed.
To start CLI, do one of the following:
■Start the 3ware CD and at the 3ware Escalade menu, click Run CLI.
■Or, open a console window and at the command prompt, enter
tw_cli
■OR, double-click the CLI icon in a folder.
The CLI prompt is displayed in a DOS console window.
Installing the 3ware CLI on Linux and FreeBSD
3ware CLI can be installed from the 3ware software CD-ROM, or
downloaded from the 3ware web site, www.3ware.com.
You will need to be root or have root privileges to install the CLI to
/usr/sbin and to run the CLI.
Filename: tw_cli.tar
To install the CLI, type the following as root:
tar xf tw_cli.tar -C /usr/sbin
To install the CLI to a different location, change /usr/sbin/ to the desired
location.
Note: The installation location needs to be in the environment path
for root to execute the CLI without using complete paths (i.e., if
installed to /usr/sbin/, you can type tw_cli on the command
line, otherwise you will have to type the complete path:
/home/user/tw_cli

Introduction to the 3ware Command Line Interface
63ware 9000 Series Serial ATA Controller CLI Guide
Working with 3ware CLI
You can work with the 3ware CLI in different ways:
■Interactively, entering commands at the main prompt
■As a series of single commands
■By creating a script—an input file with multiple commands
This first section shows examples of each of these ways.
Examples shown in the CLI Reference chapter reflect the interactive method.
Using the command interface interactively
You can use 3ware CLI interactively, entering commands at the main prompt
and observing the results on the screen.
To use the CLI interactively
1 Enter the following command:
# tw_cli
The main prompt is displayed, indicating that the program is awaiting a
command.
3ware CLI>
2 At the CLI prompt, you can enter commands to get, set, or maintain 3ware
controllers.
For example
3ware CLI>info
Displays all of the controllers in the system.
To display details of a single controller (assumed to be c0) and its
attached units, enter:
3ware CLI>info c0
To display details of a single unit (assumed to be u0) on the single
controller, enter:
3ware CLI>info c0 u0
Using a single command with output
You can use 3ware CLI with line arguments, processing a single command at
a time. To do so, simply enter the command and the arguments.
Syntax
tw_cli <command line arguments>

Understanding RAID Concepts and Levels
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Example
tw_cli info c0 u0
This example gets information for unit0 of controller0. For complete
information about the info commands, see “Info Commands” on page 18.
Using an input file to execute a script
You can operate 3ware CLI scripts by executing a file. The file is a text file
containing a list of CLI commands which you have entered in advance. Each
command must be on a separate line.
Syntax
tw_cli -f <filename>
Where <filename> is the name of the text file you want to execute.
Example
tw_cli -f clicommand.txt
This example executes the file clicommand.txt, and runs the CLI commands
included in that file.
Scripting Example
Here is an example using a text file called info.txt, containing the
following two commands:
info c0 u0
info c1 u0
To run the script, enter:
tw_cli -f info.txt
3ware CLI displays information about unit 0 on controller 0 and unit 0 on
controller 1.
Understanding RAID Concepts and Levels
The next few pages introduce RAID concepts you may find useful. For
additional information about installing and managing your 3ware controller,
see the 3ware 9000 Series Serial ATA RAID Controller User Guide.
3ware controllers use a Redundant Array of Inexpensive Disks (RAID) to
increase your storage system’s performance and provide fault tolerance
(protection against data loss).
The following concepts are important to understand when working with a
RAID controller:

Introduction to the 3ware Command Line Interface
83ware 9000 Series Serial ATA Controller CLI Guide
■Arrays and Units. In the storage industry, the term “array” is used to
describe two or more disk drives that appear to the operating system as a
single unit. When you work with 3ware software, “unit” is the term used
to refer to an array of disks that is configured and managed through the
3ware software. Single-disk units can also be configured in the 3ware
software.
■Mirroring. Mirrored arrays write data to paired drives simultaneously. If
one drive fails, the data is preserved on the paired drive. Mirroring
provides data protection through redundancy. In addition, mirroring using
a 3ware controller provides improved performance because 3ware’s
TwinStor technology reads from both drives simultaneously.
■Striping. Striping across disks allows data to be written and accessed on
more than one drive, at the same time. Striping concatenates each drive’s
capacity into one large volume. Striped disk arrays achieve high transfer
rates and provide improved performance.
■Distributed Parity. Parity works in combination with striping on RAID 5
and RAID 50. Parity information is written to each of the striped drives,
in rotation. Should a failure occur, the data on the failed drive can be
reconstructed from the data on the other drives.
■Hot Swap. The process of swapping out a drive without having to shut
down the system. This is useful when you need to swap out a degraded
drive, manually or automatically, with a pre-designated spare.
■Array Roaming. The process of swapping out or swapping in a
configured unit without having to shut down the system. This is useful if
you need to move the unit to another controller.
■Disk Roaming. The process of removing a unit from a controller and
putting it back later, either on the same controller, or a different one, and
having it recognized as a unit. The disks may be in a different order than
they initially occupied, without harm to the data.
Available RAID Configurations
The following RAID levels and configurations are available for drives
attached to a 3ware controller:
■RAID 0
■RAID 1
■RAID 5
■RAID 10
■RAID 50
■Single Disk
■JBOD
■Hot Spare

Understanding RAID Concepts and Levels
www.3ware.com 9
RAID 0
Provides striping, but no mirroring. Striped disk arrays achieve high transfer
rates because they can read and write data on more than one drive
simultaneously. The stripe size is configurable in the 3ware CLI, 3ware BIOS
Manager (3BM) and in the 3ware Disk Manager (3DM 2). Requires a
minimum of two drives.
When drives are configured in a striped disk array (see Figure 1), large files
are distributed across the multiple disks using RAID 0 techniques.
Striped disk arrays give exceptional performance, particularly for data
intensive applications such as video editing, computer aided design and
geographical information systems.
RAID 0 arrays are not fault tolerant. The loss of any drive results in the loss of
all the data in that array.
Figure 1. RAID 0 Configuration Example
RAID 1
Also known as a mirrored array. Mirroring is done on pairs of drives.
Mirrored disk arrays write data to two drives using RAID 1 algorithms (see
Figure 2). This gives your system fault tolerance by preserving the data on
one drive if the other drive fails. Fault tolerance is a basic requirement for
mission critical systems like web and database servers.
3ware uses a patented technology, TwinStor®, on RAID 1 arrays for
improved performance during sequential read operations. With TwinStor
technology, read performance is twice the speed of a single drive during
sequential read operation.
The adaptive algorithms in TwinStor technology boost performance by
distinguishing between random and sequential read requests. For the
sequential requests generated when accessing large files, both drives are used,
with the heads simultaneously reading alternating sections of the file. For the
smaller random transactions, the data is read from a single optimal drive head.

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10 3ware 9000 Series Serial ATA Controller CLI Guide
Figure 2. RAID 1 Configuration Example
RAID 5
Combines striping data with parity (exclusive OR) to restore data in case of a
drive failure. This array type provides performance, fault tolerance, high
capacity, and storage efficiency. Requires a minimum of three drives.
Parity information is distributed across all drives rather than being
concentrated on a single disk (see Figure 3). This avoids throughput loss due
to contention for the parity drive.
Figure 3. RAID 5 Configuration Example
RAID 10
This array is a combination of RAID 1 with RAID 0. Striped and mirrored
arrays for fault tolerance and high performance. Requires a minimum of four
drives to use both RAID 0 and RAID 1 techniques.
When drives are configured as a striped mirrored array, the disks are
configured using both RAID 0 and RAID 1 techniques, thus the name RAID
10 (see Figure 4). A minimum of four drives are required to use this
technique. The first two drives are mirrored as a fault tolerant array using
RAID 1. The third and fourth drives are mirrored as a second fault tolerant
array using RAID 1. The two mirrored arrays are then grouped as a striped
RAID 0 array using a two tier structure. Higher data transfer rates are
achieved by leveraging TwinStor and striping the arrays. RAID 10 is available
on the four, eight, and twelve port 3ware Serial ATA RAID Controllers.
RAID 5
A Blocks
0 parity
A4
A3
A2
A1 1 parity
B4
B3
B2 2 parity
C4
C3
C1
3 parity
D4
D2
D1
4 parity
E3
E2
E1
B0 C0 D0 E0
B Blocks C Blocks D Blocks E Blocks

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Figure 4. RAID 10 Configuration Example
RAID 50
This array is a combination of RAID 5 with RAID 0. This array type provides
fault tolerance and high performance. Requires a minimum of six drives.
Several combinations are available with RAID 50. For example, on a 12-port
controller, you can have a grouping of 3, 4, or 6 drives. A grouping of 3 means
that the RAID 5 arrays used have 3 disks each; four of these 3-drive RAID 5
arrays are striped together to form the 12-drive RAID 50 array.
Single Disk
A single drive that has been configured as a unit through 3ware software. Like
disks in other RAID configurations, single disks contain 3ware Disk Control
Block (DCB) information and are seen by the OS as available units.
JBOD
A JBOD is an unconfigured disk attached to your 3ware RAID controller.
JBOD configuration is no longer supported in the 3ware 9000 series. 3ware
recommends that you use Single Disk as a replacement for JBOD, to take
advantage of advanced features such as caching. If you are migrating JBODS
from a 7000/8000 controller, you can enable support for them. For more
information, contact Technical Support
Hot Spare
A single configured drive, available so that a redundant array can be rebuilt in
case of drive failure.
For additional information about RAID levels, see the article “RAID Primer”
on the 3ware website, at: http://www.3ware.com/products/pdf/
RAID_Primer.pdf.
Determining What RAID Level to Use
Select the RAID configuration to use based on the applications to be used on
the system, whether performance or data protection is of primary importance,
and the number of disk drives available for use.

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12 3ware 9000 Series Serial ATA Controller CLI Guide
Review the information under “Understanding RAID Concepts and Levels”
on page 7 to determine the type of RAID configuration most appropriate for
your needs and use the tables below to determine what RAID levels are
available, based on your particular controller model and the number of
available drives.
The RAID configurations available to you are determined by the number of
ports on your controller, and the number drives attached to those ports. You
can configure all drives in one unit, or you can configure multiple units, if you
have enough drives.
Table 2: Possible Configurations Based on Number of Drives
# Drives Possible RAID Configurations
1 Single or spare drive
2 RAID 0 or RAID 1
3 RAID 0, RAID 5, or RAID 1 + spare
4 RAID 5 + hot spare
RAID 10
Combination of RAID 0, RAID 1, single disk
5 RAID 5 + hot spare
RAID 10 + hot spare
Combination of RAID 0, RAID 1, hot spare
6 or more RAID 50
Depending on the number of drives, a RAID 50 may contain from
2 to 4 subunits. For example, with 12 drives, possible RAID 50
configurations include 2 subunits of 6, 3 subunits of 4, or 4
subunits of 3. With 10 drives, a RAID 50 will contain 2 subunits of
5 drives each.
Combination of RAID 0, 1, 5, 10, hot spare, and single disk

Understanding RAID Concepts and Levels
www.3ware.com 13
Drive Capacity Considerations
The capacity of each drive is limited to the capacity of the smallest drive in
the array. The total array capacity is defined as follows:
Table 3: Drive Capacity
RAID Level Capacity
RAID 0 (number of drives) X (capacity of the smallest drive)
RAID 1 capacity of the smallest drive
RAID 5 (number of drives - 1) X (capacity of the smallest drive)
Storage efficiency increases with the number of disks:
storage efficiency = (number of drives -1) / (number of drives)
RAID 10 (number of drives / 2) X (capacity of smallest drive)
RAID 50 (number of drives - number of groups of drives) X (capacity of the
smallest drive)

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14 3ware 9000 Series Serial ATA Controller CLI Guide

www.3ware.com 15
CLI Reference
This chapter provides detailed information about the 3ware CLI commands
Info, Maint, Sched, Alarms, Set, and Help.
Note: All information contained in this document that describes
usage for the 3ware 9000 series products should not be used with
3ware 7000 or 8000 series controllers.
Info. Information commands provide all information and settings about the
3ware controllers, including array types, array status, array settings, detail
controller information, and detail drive information. For details, see “Info
Commands” on page 18.
Maint. Maintenance commands perform all maintenance operations on the
drives and arrays connect to the 3ware controller. Typical operations include:
create array, delete array, rebuild array, verify array, and remove array from
the controller. For details, see “Maint Commands” on page 28.
Warning: Operations under the maint command can destroy data,
so care should be taken before using this command; CLI does not
prompt before the operation is committed.
Sched. Scheduling commands only affect the 9000 controller. Schedule
commands allow you to schedule different time slots for background tasks
such as rebuild, verify, and selftest. For details, see “Sched Commands” on
page 36.
In order to use CLI scheduling commands with 7000 and 8000 controllers,
you must use them in conjunction with a time-driven scheduling component
under Windows, Linux, or FreeBSD. For example, under Linux, you can use
the cron daemon scheduling utility with the CLI commands for rebuild, verify,
and mediascan. (For more information about the specific CLI commands, see

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16 3ware 9000 Series Serial ATA Controller CLI Guide
“Maint Commands” on page 28 and refer to your Linux documentation or
manpages.)
In addition, 3ware also includes on the 3ware CD a utility named
tw_sched(1), which is a wrapper around tw_cli(1). Used in conjunction with a
time-driven scheduler such as crond(1d), it provides background task
scheduling features such as rebuild, verify, and mediascan. For details about
tw_sched(1), see the manpages for it.
Scheduling for the 7000 and 8000 series models can also be done using 3DM
1.x. (Note that 3DM 2 only provides scheduling only for 9000 series models.)
Alarms. The Alarms command allows you to display Asynchronous Event
Notification (AEN) events that have been generated by controllers. AEN
events have different levels of severity. They can be extracted and archived
for overall trend analysis. For details, see “Alarms Commands” on page 41.
CLI does not store alarms command in a log file, so when you reboot, alarms
in the previous session will be lost. To preserve the alarms through reboot,
you can either extract the alarms from CLI and store them in a file, or install
3DM 2, which does log alarm messages. For more information, see the 3ware
9000 Series Serial ATA RAID Controller User Guide.
Set. Setting commands can be used to modify and change controller and array
settings. Settings that can be changed include: rebuild rate, verify rate, and
turning on or off cache, autoverify, or overwriteECC. For details, see “Set
Commands” on page 43.
Help. Help commands. Options in this category allow you to display help
information on the other commands and options. For details, see “Help
Commands” on page 45.
Throughout this chapter the examples reflect the interactive method of
executing 3ware CLI.
Conventions
The following conventions are used through this guide:
■In text, monospace font is used for code and for things you type.
■In commands, an italic font indicates items that you must specify, such as
a controller ID, or a unit ID.
■In commands, brackets around an item indicates that it is optional.
■In commands, ellipses (. . .) indicate that more than one parameter can be
included.
■In commands, a brace (|) indicates an 'or' situation where the user has a
choice between more than one option, but only one can be specified.