Advanced Data Guarding for the
Smart Array 5300 Controller
Reference Guide
First Edition (December 2000)
Part Number 188270-001
Compaq Computer Corporation
Notice
© 2000 Compaq Computer Corporation
COMPAQ, the Compaq logo, SmartStart, registered United States Patent and Trademark Office.
SoftPaq is a trademark of Compaq Information Technologies Group, L.P.
Microsoft, MS-DOS, Windows, and Windows NT are registered trademarks of Microsoft Corporation.
All other product names mentioned herein may be trademarks and/or registered trademarks of their
respective companies.
Compaq shall not be liable for technical or editorial errors or omissions contained herein. The
information in this document is subject to change without notice.
THE INFORMATION IN THIS PUBLICATION IS PROVIDED “AS IS” WITHOUT WARRANTY
OF ANY KIND. THE ENTIRE RISK ARISING OUT OF THE USE OF THIS INFORMATION
REMAINS WITH RECIPIENT. IN NO EVENT SHALL COMPAQ BE LIABLE FOR ANY DIRECT,
CONSEQUENTIAL, INCIDENTAL, SPECIAL, PUNITIVE OR OTHER DAMAGES
WHATSOEVER (INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS
PROFITS, BUSINESS INTERRUPTION OR LOSS OF BUSINESS INFORMATION), EVEN IF
COMPAQ HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES AND WHETHER
IN AN ACTION OF CONTRACT OR TORT, INCLUDING NEGLIGENCE.
The limited warranties for Compaq products are exclusively set forth in the documentation
accompanying such products. Nothing herein should be construed as constituting a further or
additional warranty.
Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
First Edition (December 2000)
Part Number 188270-001
Contents
About This Guide
Text Conventions ........................................................................................................ v
Symbols in Text .........................................................................................................vi
Symbols on Equipment .............................................................................................. vi
Important Safety Information....................................................................................vii
Getting Help .............................................................................................................. vii
Compaq Technical Support................................................................................ vii
Compaq Website ............................................................................................... viii
Compaq Authorized Reseller ............................................................................viii
Chapter 1
Introduction: RAID ADG
Chapter 2
Installation
Preliminary Steps .....................................................................................................2-1
Locating the Connector ............................................................................................2-2
Installing the RAID ADG Enabler Module.............................................................. 2-3
Removing the Enabler Module.................................................................................2-4
Chapter 3
System Setup
Configuring a New System for RAID ADG ............................................................3-2
Windows NT and Windows 2000.....................................................................3-2
NetWare ............................................................................................................3-3
Migrating an Existing Logical Drive to RAID ADG ...............................................3-4
Windows NT and Windows 2000.....................................................................3-4
NetWare ............................................................................................................3-5
Assigning an Online Spare Drive.............................................................................3-5
iv Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
System Setup
continued
Performance Tuning ................................................................................................ 3-7
Changing the Cache Read/Write Allocation..................................................... 3-7
Optimizing the Stripe Size................................................................................ 3-8
Changing the Fault Tolerance Mode .............................................................. 3-10
Appendix A
Regulatory Compliance Notices
Federal Communications Commission Notice ........................................................A-1
Class A Equipment...........................................................................................A-2
Class B Equipment ...........................................................................................A-2
Modifications....................................................................................................A-3
Cables ...............................................................................................................A-3
Canadian Notice (Avis Canadien) ...........................................................................A-3
Class A Equipment...........................................................................................A-3
Class B Equipment ...........................................................................................A-4
European Union Notice ...........................................................................................A-4
Japanese Notice .......................................................................................................A-4
Taiwanese Notice ....................................................................................................A-5
Appendix B
Electrostatic Discharge
Preventing Electrostatic Damage.............................................................................B-1
Grounding Methods................................................................................................. B-2
Appendix C
Reliability Data
Appendix D
Additional POST Error Messages
Appendix E
Questions and Answers
Index
This guide describes the features of RAID ADG and the installation of the
RAID ADG Enabler Module onto the Smart Array 5300 controller board.
Text Conventions
This document uses the following conventions to distinguish elements of text:
Keys Keys appear in boldface. A plus sign (+) between
USER INPUT User input appears in a different typeface and in
FILENAMES File names appear in uppercase italics.
About This Guide
two keys indicates that they should be pressed
simultaneously.
uppercase.
Menu Options,
Command Names,
Dialog Box Names
COMMANDS,
DIRECTORY NAMES,
and DRIVE NAMES
Type When you are instructed to type information, type
Enter When you are instructed to enter information, type
These elements appear in initial capital letters.
These elements appear in uppercase.
the information without pressing the Enter key.
the information and then press the Enter key.
vi Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
Symbols in Text
These symbols may be found in the text of this guide. They have the following
meanings.
WARNING: Text set off in this manner indicates that failure to follow directions
in the warning could result in bodily harm or loss of life.
CAUTION: Text set off in this manner indicates that failure to follow directions
could result in damage to equipment or loss of information.
IMPORTANT: Text set off in this manner presents clarifying information or specific
instructions.
NOTE: Text set off in this manner presents commentary, sidelights, or interesting points
of information.
Symbols on Equipment
These icons may be located on equipment in areas where hazardous conditions
may exist.
Any surface or area of the equipment marked with these symbols
indicates the presence of electrical shock hazards. Enclosed area
contains no operator serviceable parts.
WARNING: To reduce the risk of injury from electrical shock hazards,
do not open this enclosure.
Any RJ-45 receptacle marked with these symbols indicates a Network
Interface Connection.
WARNING: To reduce the risk of electrical shock, fire, or damage to
the equipment, do not plug telephone or telecommunications
connectors into this receptacle.
Any surface or area of the equipment marked with these symbols
indicates the presence of a hot surface or hot component. If this
surface is contacted, the potential for injury exists.
WARNING: To reduce the risk of injury from a hot component, allow
the surface to cool before touching.
Power Supplies or Systems marked with these symbols
indicate the equipment is supplied by multiple sources of
power.
WARNING: To reduce the risk of injury from electrical shock,
remove all power cords to completely disconnect power from
the system.
Important Safety Information
Before installing this product, read the Important Safety Information document
provided.
About This Guide vii
Getting Help
If you have a problem and have exhausted the information in this guide, you
can get further information and other help in the following locations.
Compaq Technical Support
You are entitled to free hardware technical telephone support for your product
for as long you own the product. A technical support specialist will help you
diagnose the problem or guide you to the next step in the warranty process.
In North America, call the Compaq Technical Phone Support Center at
1-800-OK-COMPAQ
Outside North America, call the nearest Compaq Technical Support Phone
Center. Telephone numbers for world wide Technical Support Centers are
listed on the Compaq website. Access the Compaq website by logging on to
the Internet at www.compaq.com.
1
For continuous quality improvement, calls may be recorded or monitored.
1
. This service is available 24 hours a day, 7 days a week.
viii Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
Be sure to have the following information available before you call Compaq:
■
Technical support registration number (if applicable)
■
Product serial number (s)
■
Product model name(s) and numbers(s)
■
Applicable error messages
■
Add-on boards or hardware
■
Third-party hardware or software
■
Operating system type and revision level
■
Detailed, specific questions
Compaq Website
The Compaq website has information on this product as well as the latest
drivers and Flash ROM images. You can access the Compaq website by
logging on to the Internet at www.compaq.com.
Compaq Authorized Reseller
For the name of your nearest Compaq Authorized Reseller:
■
In the United States, call 1-800-345-1518.
■
In Canada, call 1-800-263-5868.
■
Elsewhere, see the Compaq website for locations and telephone
numbers.
Chapter
1
Introduction: RAID ADG
RAID ADG is similar to RAID 5 in that data protection is achieved by writing
parity information to the physical drives in the array. With RAID ADG,
however, two sets of parity data are used (Figure 1-1). These two sets are
different, and each set occupies a capacity equivalent to that of one of the
constituent drives. (For further information about other RAID levels, refer to
the Compaq Smart Array 5300 Controller User Guide.)
B1
B3
P5,6
P7,8
Figure 1-1. RAID ADG, showing data blocks (B) and two sets of parity data (P)
RAID ADG is most useful when data loss cannot be accepted, but low cost of
implementation is also desirable. The probability that a system will suffer data
loss when configured with RAID ADG is less than when configured with
either RAID 1 or RAID 5 (see Appendix C for reliability data).
B2
P3,4
P5,6
B7
P1,2
P3,4
B5
B8
P1,2
B4
B6
P7,8
1-2 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
The main advantages of RAID ADG are:
■
High read performance
■
High data availability – any two drives can fail without loss of critical
data
The only significant disadvantage is a relatively low write performance (lower
than RAID 5), due to the need for two sets of parity data.
The following table summarizes the most important features of the different
varieties of RAID available. The decision chart in Figure 1-2 may help you
determine which RAID option is best for your situation.
Table 1-1
Summary of RAID Features
RAID 0 RAID 1 / RAID 0+1 RAID 5 RAID ADG
Alternative name Striping (no
fault tolerance)
Usable drive space* 100% 50% 67% to 93% 50% to 96%
Usable drive space
formula
Minimum number
of hard drives
Tolerant of single
hard drive failure?
Tolerant of multiple
simultaneous hard
drive failure?
Read performance High High High High
Write performance High Medium Low Low
Relative cost Low High Medium Medium
*Note: The value for usable drive space is calculated assuming a maximum of 14 hard drives of the same
capacity (or a maximum of 56 for RAID ADG) with no online spares. Compaq recommends that these
maximum figures (excluding any allowable online spares) are not exceeded when configuring a drive array,
due to the increased likelihood of logical drive failure with more hard drives.
n n/2 (n-1)/n (n-2)/n
12 34
No Yes Yes Yes
No In RAID 0+1, only
Mirroring Distributed
Data Guarding
No Yes
when the failed
drives are not
mirrored to each
other
Advanced Data
Guarding
Introduction: RAID ADG 1-3
M
OST IMPORTANT
Fault tolerance
Cost effectiveness
I/O performance
Figure 1-2. Choosing a RAID method
A
LSO IMPORTANT
Cost effectiveness
I/O performance
Fault tolerance
I/O performance
Cost effectiveness
Fault tolerance
S
UGGESTED
RAID ADG
RAID 0+1
RAID ADG
RAID 5 (RAID 0 if fault
tolerance is not required)
RAID 5 (RAID 0 if fault
tolerance is not required)
RAID 0+1
RAID L
EVEL
For Advanced Data Guarding to be available as a fault-tolerance option on
your system, the RAID ADG Enabler Module must be installed on the Smart
Array 5300 controller in the server. Also, you will need to have at least 64 MB
of read/write cache on the controller.
Preliminary Steps
WARNING: To reduce the risk of personal injury or damage to the equipment,
consult the safety information and user documentation provided with your
computer before attempting the installation.
Many computers are capable of producing energy levels that are considered
hazardous. These computers are intended to be serviced by qualified personnel
trained to deal with those hazards. Do not remove enclosures or attempt to
bypass any interlocks that may be provided for the purpose of removing these
hazardous conditions.
Chapter
2
Installation
CAUTION: Electrostatic discharge (ESD) can damage electronic components. Be
sure you are properly grounded before beginning this procedure. See Appendix
B for ESD information.
Before installing or removing the RAID ADG Enabler Module:
1. Perform a normal system shutdown.
CAUTION: In systems using external data storage, be sure the server is the first
unit powered down and the last to be powered back up. This will ensure that the
system will not erroneously mark the drives as failed.
2-2 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
2. Turn off the server.
3. Turn off any peripheral devices attached to the server.
4. Unplug the AC power cord from the outlet, then from the server.
5. Disconnect any peripheral devices from the server.
WARNING: To reduce the risk of personal injury from hot surfaces, allow the
internal system components and hot-plug hard drives to cool before touching.
6. Remove or open the access panel.
7. Remove the Smart Array 5300 controller from the PCI slot.
Locating the Connector
The connector for the RAID ADG Enabler Module is located at the corner of
the controller board near the Array Accelerator connector socket (Figure 2-1).
Figure 2-1. Location of the RAID ADG Enabler Module connector on the Smart
Array 5300 controller board
The module attaches to the controller board with the narrow tab (circled in
Figure 2-2) nearest to the corner of the controller board. This tab can be
pressed outwards during installation to allow the module to be more readily
inserted into the board. The clips at each end of the module fit into the slots on
the board.
Figure 2-2. Aligning the module on the controller board
Installing the RAID ADG Enabler Module
To install the RAID ADG Enabler Module:
1. Perform the preliminary steps described earlier in this chapter.
Installation 2-3
2. Ensure that the Array Accelerator on your Smart Array 5300 controller
has at least 64 MB of read/write cache.
3. Hold the module at an angle and insert the rear end of the module into
the appropriate slot 1.
1
Figure 2-3. Installing the module
2
a
b
2-4 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
4. Use one thumb to press the tab at the top of the rear end outward 2(a)
while using the other thumb to gently press the other end of the module
2(b) into the connector and slot on the controller board.
5. Replace the Smart Array 5300 controller in the server.
6. Replace or close the access panel.
7. Reconnect peripherals and power.
8. Power on the system.
Removing the Enabler Module
When replacing a Smart Array 5300 controller, you may want to remove the
RAID ADG Enabler Module from the old controller and install it onto the new
controller.
To remove the RAID ADG Enabler Module:
1. Perform the preliminary steps listed earlier in this chapter.
2. Press the innermost plastic clip under the controller board towards the
other clip 1, and push the module out of the board 2.
1
2
Figure 2-4. Removing the RAID ADG Enabler Module
Chapter
3
System Setup
When you have installed the RAID ADG Enabler Module, your array
controller can be configured to use Advanced Data Guarding.
The greater reliability of RAID ADG (see Appendix C) allows an array to be
built with up to 56 drives, spanning all four channels of a Smart Array 5300
controller and its attached 2- to 4-channel adapter board. Furthermore,
although the maximum capacity of a logical drive is 502 GB, some operating
systems (such as Windows NT and Windows 2000) will allow multiple logical
drives to be combined into a single user volume. Consult your operating
system documentation for details.
Brief instructions for setting up your system with RAID ADG are given below
for Windows 2000, Windows NT, and NetWare. More detailed information
can be found in the Compaq Smart Array 5300 Controller User Guide.
IMPORTANT: Although data loss is not anticipated, Compaq recommends that you back
up all data before changing the fault tolerance setting. This backup data may also be used
to return the system to the original configuration, if necessary.
NOTE: A logical volume that is configured for RAID ADG can only be migrated to other
controllers that are also configured to support RAID ADG.
3-2 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
Configuring a New System for RAID ADG
Windows NT and Windows 2000
There are three main steps to configure a new system for RAID ADG:
1. Set up an array.
2. Assign hard drives to the array.
3. Create logical drives within the array.
Setting Up an Array
1. Check that you have the latest version of the configuration utility by
visiting the Compaq website (www.compaq.com). Download and install
the newer version if necessary. An ACU program icon will
automatically be generated on the desktop.
2. Double-click the ACU icon.
3. Select the controller (Smart Array 5300) from the drop-down list in the
top left corner of the main ACU screen.
4. Click the Settings button in the Controller section in the top right corner
of the main ACU screen.
5. Set the rebuild priority, expansion priority, and accelerator ratio.
6. Click the Done button to activate the settings and return to the main
ACU screen.
Assigning Hard Drives to the Array
1. Click the Create Array button in the Controller section of the screen.
2. Select the hard drives that are to make up the array, remembering to
leave one for the online spare if desired. With RAID ADG, you may
select up to 56 drives per array.
3. Click the Assign Drive(s) to Array button.
4. Select the hard drive that is to be the online spare.
5. Click the Assign Spare to Array button.
6. Click the Done button to activate the settings and return to the main
ACU screen.
NetWare
System Setup 3-3
Creating a Logical Drive within the Array
1. Select the array from the left-hand side of the main ACU screen.
2. Click the Create Logical Drive button
3. Select the RAID ADG check box on the screen that is displayed.
4. Enable the Array Accelerator.
5. Change the stripe size, if required. The default setting is 16 kB for
RAID ADG, suitable for most common uses. The Stripe Size section
later in this chapter discusses stripe sizes most useful for various
applications.
6. Change the logical drive size, if desired.
7. Click the Done button to activate the settings and return to the main
ACU screen.
8. Choose Save Configuration from the Controller menu.
9. Choose Exit from the Controller menu.
1. Check that you have the latest support pack or operating system patch
from the Novell website installed on your system.
2. Check that you have the latest drivers for the Smart Array 5300 from the
Compaq website installed on your system.
3. Open the CPQONLIN utility.
In a new system, with no logical drives configured, the auto-
configuration wizard is automatically displayed.
4. Select RAID ADG as the fault tolerance level. The wizard creates and
configures a logical drive on an array in your system using this RAID
setting. Alternatively, you can choose to custom configure your system.
5. Save the changes and close out of CPQONLIN.
3-4 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
Migrating an Existing Logical Drive to RAID ADG
Windows NT and Windows 2000
If you are migrating from a logical drive that is configured for RAID 0 or
RAID 5, you will need to expand the array before migrating to RAID ADG.
Check that you have the latest version of the configuration utility by visiting
the Compaq website (www.compaq.com). Download and install the newer
version if necessary. An ACU program icon will automatically be generated
on the desktop.
Expanding the Array
1. Add at least one extra hard drive to your system if migrating from
RAID 5, or two extra hard drives if migrating from RAID 0. The
capacity of each added drive should be no less than that of the smallest
hard drive currently used in the logical volume.
2. Double-click the ACU icon on the desktop.
3. Select the array to be expanded from the left-hand side of the main ACU
screen.
4. Click the Expand button.
5. Select the extra hard drives added, except any added spare.
6. Click the Assign Drive(s) to Array button.
7. Select the online spare, if added.
8. Click the Assign Spare to Array button.
9. Continue the migration when expansion has finished.
Migrating the Logical Drive
1. In the ACU, click the Migrate button in the Logical Drive section on the
right-hand side of the main ACU screen.
2. Select the RAID ADG check box on the Migrate RAID/Stripe Size
screen that is displayed.
NetWare
System Setup 3-5
3. Change the stripe size, if required. The default setting is 16 kB for
RAID ADG, suitable for most common uses. The Stripe Size section
later in this chapter discusses stripe sizes most useful for various
applications.
4. Click the Done button.
5. Choose Save Configuration from the Controller menu.
6. Choose Exit from the Controller menu.
If you are migrating from a logical drive that is configured for RAID 0 or
RAID 5, you will need to expand the array before migrating to RAID ADG.
Check that you have the latest support pack or operating system patch from the
Novell website installed on your system, and check that you also have the
latest drivers for the Smart Array 5300 from the Compaq website.
1. Add at least one extra hard drive to your system if migrating from
RAID 5, or two extra hard drives if migrating from RAID 0. The
capacity of each added drive should be no less than that of the smallest
hard drive currently used in the logical volume.
2. Open the CPQONLIN utility.
3. Expand the array if necessary, and continue migrating to RAID ADG
when expansion is complete.
4. On the Main Configuration View screen, highlight the logical drive that
is to be reconfigured for RAID ADG.
5. Click the Drive Settings option on the Logical Drive menu.
6. Choose RAID ADG from the list.
7. Choose a stripe size. The Stripe Size section later in this chapter
discusses stripe sizes most useful for various applications.
8. Save the changes and close out of CPQONLIN.
Assigning an Online Spare Drive
In fault-tolerant systems, addition of an online spare (hot spare) to a logical
drive provides further protection against data loss caused by hard drive failure.
As soon as drive failure occurs, missing data can be automatically rebuilt from
parity data onto the online spare. Without an online spare there is a chance that
3-6 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
more hard drives will fail before the failed drive is replaced, leading to failure
of the complete logical drive and consequent loss of data. This is less likely
with RAID ADG than RAID 5, since RAID ADG can sustain failure of two
drives.
Data is rebuilt to the online spare at a rate of 10 to 20 minutes per gigabyte,
depending on the priority assigned to rebuilding and the total number of drives
in the array.
There can only be one spare drive per array. However, an online spare may be
assigned to more than one array, if efficient use of drive capacity is important.
The capacity of the online spare should be at least as large as that of the other
drives in the array.
These are the fault-tolerance options available if you have a limited number of
drives (listed from best to worst):
■
RAID ADG with 1 spare (3 drives used for fault tolerance)
■
RAID ADG without a spare (2 drives used for fault tolerance)
■
RAID 5 with 1 spare (2 drives used for fault tolerance)
■
RAID 5 without a spare (1 drive used for fault tolerance)
■
RAID 0 (no fault tolerance)
To assign an online spare to an array during configuration, see the previous
sections in this chapter.
To assign an online spare to an array after configuration:
1. Ensure that at least one hard drive containing no data is attached to the
same controller as the array.
2. Open the Array Configuration Utility.
3. Select the array in the Main ACU screen.
4. Click the Modify button in the Array section of the Main screen.
5. Select the drive to be used as an online spare.
6. Click the Assign Spare to Array button.
7. Click the Done button.
8. Click the Settings button in the Controller section on the right side of the
Main ACU screen.
9. In the Rebuild Priority section of the Controller Settings screen, select
High if rebuilding data is more important than handling operating
system requests; select Low if the controller should rebuild data only
when it is idle.
IMPORTANT: Selecting a high rebuild priority will result in reduced server performance
while the rebuild is in progress. Setting the rebuild priority to Low allows normal server
performance, since rebuilding only occurs when the server is idle.
10. Click the Done button.
11. Choose Save Configuration from the Controller menu.
12. Choose Exit from the Controller menu.
Performance Tuning
There are several ways in which you can optimize the performance of your
system. You can:
■
Change the accelerator cache percentage allocated to reads and writes.
■
Choose a stripe size more suitable for the type of data transfer common
to your system.
System Setup 3-7
■
Change the fault tolerance mode to one that requires less overhead.
■
Enlarge the logical drive to span all four controller channels.
Changing the Cache Read/Write Allocation
By default, the Array Accelerator cache capacity is equally divided between
reads and writes. If your server application has significantly more reads than
writes (or vice versa), you may need to change this setting to improve
performance.
NOTE: 16 MB of cache is used for a transfer buffer (8 MB with 32-MB Array Accelerator
boards).
1. Check that you have the latest version of the configuration utility by
visiting the Compaq website (www.compaq.com). Download and install
the newer version if necessary. An ACU program icon will
automatically be generated on the desktop.
2. Double-click the ACU icon.
3. Select the array in the Main ACU screen.
3-8 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
4. Click the Settings button in the Controller section on the right side of the
Main ACU screen.
5. In the Accelerator Ratio section of the Controller Settings screen that is
displayed, either click a check box by one of the choices offered or enter
a percentage in one of the fields.
6. Click the Done button.
7. Choose Save Configuration from the Controller menu.
8. Choose Exit from the Controller menu.
You may also need to change the stripe size. This is described in the following
section.
Optimizing the Stripe Size
Stripe size is the size of the data block written to a hard drive in each stripe of
the logical drive. Table 3-1 summarizes the stripe sizes available for each of
the fault tolerance methods. The default stripe size gives acceptable
performance in most circumstances. When high performance is important, you
can modify the stripe size according to the information in Table 3-2.
Table 3-1
Available Stripe Sizes
Fault Tolerance Method Available Stripe Sizes (kB) Default Size (kB)
RAID 0 128, 256 128
RAID 1 or 0+1 8, 16, 32, 64, 128, 256 128
RAID 5 or RAID ADG 8, 16, 32, 64 16
Table 3-2
Optimum Stripe Size
Type of Server Application Suggested Stripe Size Change
Mixed read/write Accept the default value
Mainly read (such as database or
Internet applications)
Mainly write (such as image
manipulation applications)
Larger stripe sizes work best
Smaller stripes for RAID 5, RAID ADG
Larger stripes for RAID 0, RAID 0+1, RAID 1
System Setup 3-9
To change the stripe size, carry out the procedure described for your operating
system in one of the following sections.
Windows NT and Windows 2000
1. Check that you have the latest version of the configuration utility by
visiting the Compaq website (www.compaq.com). Download and install
the newer version if necessary. An ACU program icon will
automatically be generated on the desktop.
2. Double-click the ACU icon.
3. Select the logical drive to be reconfigured from the left-hand side of the
main ACU screen.
4. Click the Migrate button in the Logical Drive section on the right-hand
side of the main ACU screen.
5. Change the stripe size.
6. Click the Done button.
7. Click Save Configuration on the Controller menu.
8. Click Exit on the Controller menu.
NetWare
1. Check that you have the latest support pack or operating system patch
from the Novell website installed on your system.
2. Check that you have the latest drivers for the Smart Array 5300 from the
Compaq website installed on your system.
3. Open the CPQONLIN utility.
4. On the Main Configuration View screen, highlight the logical drive that
is to be reconfigured.
5. Click the Drive Settings option on the Logical Drive menu.
6. Choose a stripe size.
7. Save the changes and close out of CPQONLIN.
3-10 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
Changing the Fault Tolerance Mode
Performance decreases in this order:
■
RAID 0 (highest performance, but no protection against drive failure)
■
RAID 1
■
RAID 5
■
RAID ADG
If performance is too low with your current fault tolerance method, it can be
improved by migrating to a different RAID level. Follow the steps outlined in
the section “Migrating an Existing Logical Drive to RAID ADG” earlier in
this chapter, and select a different RAID level at the appropriate step in the
sequence.
Regulatory Compliance Notices
Federal Communications Commission Notice
Part 15 of the Federal Communications Commission (FCC) Rules and
Regulations has established Radio Frequency (RF) emission limits to provide
an interference-free radio frequency spectrum. Many electronic devices,
including computers, generate RF energy incidental to their intended function
and are, therefore, covered by these rules. These rules place computers and
related peripheral devices into two classes, A and B, depending upon their
intended installation. Class A devices are those that may reasonably be
expected to be installed in a business or commercial environment. Class B
devices are those that may reasonably be expected to be installed in a
residential environment (that is, personal computers). The FCC requires
devices in both classes to bear a label indicating the interference potential of
the device as well as additional operating instructions for the user.
Appendix
A
The rating label on the device shows which class (A or B) the equipment falls
into. Class B devices have an FCC logo or FCC ID on the label. Class A
devices do not have an FCC logo or FCC ID on the label. Once the class of the
device is determined, refer to the following corresponding statement.
A-2 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
Class A Equipment
This equipment has been tested and found to comply with the limits for a
Class A digital device, pursuant to Part 15 of the FCC Rules. These limits are
designed to provide reasonable protection against harmful interference when
the equipment is operated in a commercial environment. This equipment
generates, uses, and can radiate radio frequency energy and, if not installed
and used in accordance with the instructions, may cause harmful interference
to radio communications. Operation of this equipment in a residential area is
likely to cause harmful interference, in which case the user will be required to
correct the interference at personal expense.
Class B Equipment
This equipment has been tested and found to comply with the limits for a
Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are
designed to provide reasonable protection against harmful interference in a
residential installation. This equipment generates, uses, and can radiate radio
frequency energy and, if not installed and used in accordance with the
instructions, may cause harmful interference to radio communications.
However, there is no guarantee that interference will not occur in a particular
installation. If this equipment does cause harmful interference to radio or
television reception, which can be determined by turning the equipment off
and on, the user is encouraged to try to correct the interference by one or more
of the following measures:
■
Reorient or relocate the receiving antenna.
■
Increase the separation between the equipment and receiver.
■
Connect the equipment into an outlet on a circuit different from that to
which the receiver is connected.
■
Consult the dealer or an experienced radio or television technician for
help.
Declaration of Conformity for Products Marked with the FCC logo – United States Only
This device complies with Part 15 of the FCC Rules. Operation is subject to
the following two conditions: (1) this device may not cause harmful
interference, and (2) this device must accept any interference received,
including interference that may cause undesired operation.
For questions regarding your product, contact:
Compaq Computer Corporation
P. O. Box 692000, Mail Stop 530113
Houston, Texas 77269-2000
or call 1-800- 652-6672 (1-800-OK COMPAQ). (For continuous quality
improvement, calls may be recorded or monitored.)
For questions regarding this FCC declaration, contact:
Compaq Computer Corporation
P. O. Box 692000, Mail Stop 510101
Houston, Texas 77269-2000
or call (281) 514-3333.
To identify this product, refer to the Part, Series, or Model number found on
the product.
Modifications
The FCC requires the user to be notified that any changes or modifications
made to this device that are not expressly approved by Compaq Computer
Corporation may void the user's authority to operate the equipment.
Regulatory Compliance Notices A-3
Cables
Connections to this device must be made with shielded cables with metallic
RFI/EMI connector hoods in order to maintain compliance with FCC Rules
and Regulations.
Canadian Notice (Avis Canadien)
Class A Equipment
This Class A digital apparatus meets all requirements of the Canadian
Interference-Causing Equipment Regulations.
Cet appareil numérique de la classe A respecte toutes les exigences du
Règlement sur le matériel brouilleur du Canada.
A-4 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
Class B Equipment
This Class B digital apparatus meets all requirements of the Canadian
Interference-Causing Equipment Regulations.
Cet appareil numérique de la classe B respecte toutes les exigences du
Règlement sur le matériel brouilleur du Canada.
European Union Notice
Products with the CE Marking comply with both the EMC Directive
(89/336/EEC) and the Low Voltage Directive (73/23/EEC) issued by the
Commission of the European Community.
Compliance with these directives implies conformity to the following
European Norms (in brackets are the equivalent international standards):
■
EN55022 (CISPR 22) - Electromagnetic Interference
■
EN50082-1 (IEC801-2, IEC801-3, IEC801-4) - Electromagnetic
Immunity
■
EN60950 (IEC950) - Product Safety
Japanese Notice
Regulatory Compliance Notices A-5
Taiwanese Notice
Electrostatic Discharge
A discharge of static electricity from a finger or other conductor can damage
printed circuit boards or other static-sensitive devices. This type of damage
may reduce the life expectancy of the device.
Preventing Electrostatic Damage
To prevent electrostatic damage, observe the following precautions:
■
Avoid hand contact by transporting and storing parts in static-safe
containers.
Appendix
B
■
Keep electrostatic-sensitive parts in their containers until they arrive at
static-free work stations.
■
Place parts on a grounded surface before removing them from their
container.
■
Avoid touching pins, leads, or circuitry.
■
Always make sure you are properly grounded when touching a staticsensitive component or assembly.
B-2 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
Grounding Methods
There are several methods for grounding. Use one or more of the following
measures when handling or installing electrostatic-sensitive parts:
■
Use a wrist strap connected by a ground cord to a grounded workstation
or the computer chassis. Wrist straps are flexible straps with a
minimum of 1 megohm +/- 10 percent resistance in the ground cords.
■
Use heel straps, toe straps, or bootstraps at standing workstations. Wear
the straps on both feet when standing on conductive floors or
dissipating floor mats.
■
Use conductive field service tools.
■
Use a portable field service kit with a folding static-dissipating work
mat.
If you do not have any of the suggested equipment for proper grounding, have
an Authorized Compaq Service Provider install the part.
NOTE: For additional information on static electricity or assistance with the installation of
this product, contact your Authorized Compaq Service Provider or refer to the Server
Maintenance and Service Guide.
Appendix
C
Reliability Data
Figure C-1 shows the relative probability of logical drive failure for different
RAID settings and different logical drive sizes, assuming no online spares are
present. With RAID 0, the logical drive will fail if only one physical drive
fails; with RAID 5, two physical drives must fail; and with RAID ADG, three
hard drives must fail.
The situation is more complex for RAID 0+1. The maximum number of hard
drives that can fail without failure of the logical drive is n/2. This will happen
only if none of the failed drives are mirrored to each other. In practice, logical
drive failure will usually occur before this maximum number is reached, since
the probability of a newly failed drive not being mirrored to a previously failed
drive becomes increasingly small as the number of failed drives increases.
Also note that a RAID 0+1 logical drive may fail if only two hard drives fail,
if they are mirrored to each other; the probability of this happening decreases
as the number of mirrored pairs in the array increases.
An online spare can be added to any of the fault-tolerant RAID levels to
further decrease the probability of logical drive failure to about a thousandth of
the previous level.
For RAID 0+1 and RAID 5, Compaq recommends that no more than 14
physical drives be used per logical drive. However, logical drive failure is
much less likely with RAID ADG, and Compaq supports the use of up to 56
physical drives per logical drive when running this fault-tolerance method.
C-2 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
Total number of physical drives in array
1
1 6 11 16 21 26 31 36 41 46 51 56
0.01
0.001
0.0001
1E-05
1E-06
1E-07
Relative likelihood of logical drive failure .
1E-08
0.1
RAID 0
RAID 5
RAID 0+ 1
RAID ADG
1E-09
1E-10
1E-11
Figure C-1. Probability of logical drive failure for different RAID levels
Appendix
Additional POST Error Messages
If a system fault is present when the computer is started up, Power-On SelfTest messages will display. Many of these messages are self-explanatory and
suggest corrective actions. Messages unique to the use of RAID ADG are
listed in the following table.
Table D-1
POST Error Messages
Number Message Meaning and recommended action
D
1754 Slot z drive array – RAID ADG drive(s)
configured but ADG Enabler Module is
detached or defective. Please check for
detached ADG Enabler Module. Array
Accelerator is temporarily disabled.
1755 Slot z drive array – ADG Enabler Module
appears to be defective. Please replace
the ADG Enabler Module.
An operational ADG Enabler Module must be
attached whenever RAID ADG volumes are
configured or the Array Accelerator will be
disabled. Replace the ADG Enabler Module.
Replace the defective ADG Enabler Module, or
remove it if unneeded (i.e., if no RAID ADG
logical drives are configured).
Appendix
Questions and Answers
Q: What is RAID ADG?
A: RAID ADG is an extension of RAID 5 that allows additional fault
tolerance by using two different and independent parity schemes. Data is
striped across a set of hard drives, just as with RAID 5, and the two sets of
parity data are calculated and written across all the drives in the array.
RAID ADG provides an extremely high fault tolerance, and can sustain
two simultaneous drive failures without downtime or data loss. This is a
perfect solution when data is mission-critical.
E
Q: What does the abbreviation RAID ADG mean?
A: ADG is an abbreviation for Advanced Data Guarding, the term Compaq
uses for this type of fault tolerance.
Q: When should RAID ADG be used?
A: There are three primary reasons for using RAID ADG.
! When a higher level of fault tolerance than RAID 5 is needed and
high drive capacity utilization is also required
!
When a higher level of drive capacity utilization than RAID 0+1 is
required while maintaining a high level of fault tolerance
!
When a large logical volume is needed, incorporating from 10 to 56
hard drives
E-2 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
Q: What is the difference between RAID ADG and RAID 0+1?
A: RAID ADG uses the capacity of only two hard drives for fault tolerance,
regardless of the size of the RAID volume. This means a lower cost of
implementation for six or more drives.
RAID ADG also provides a higher level of fault tolerance, since the
mathematical probability of suffering a second drive failure in the same
mirror set as an already-failed drive (in RAID 0+1) is higher than the
probability of a third drive failure in RAID ADG. However, RAID 0+1 is
the highest-performance RAID level.
Q: What is the difference between RAID ADG and RAID 5?
A: RAID ADG allows two drives to fail simultaneously without downtime or
data loss. (Data is also preserved if one drive fails and another simply has
a few bad sectors.) However, RAID 5 only allows one drive to fail. RAID
ADG thus provides a much higher level of fault tolerance than RAID 5.
Due to this higher level of protection, users can set up larger RAID
volumes, spanning up to 56 physical drives. With RAID 5, the maximum
recommended number of drives per volume is only 14.
RAID 5 and RAID ADG have equal performance when reading data, but
RAID ADG is slower when writing data due to the extra parity set that it
uses. The exact difference in performance will vary from one situation to
another.
Q: What products support RAID ADG?
A: RAID ADG is available with controller model SA-5304/128. It is also
supplied with the 128-MB cache module available as an option for the
SA-5302/32 and SA-5302/64 controllers.
Q: Does RAID ADG support online spares?
A: Yes. Customers can incorporate online spares for added data protection.
Q: How is RAID ADG activated?
A: Both a hardware key and a firmware upgrade are required. If the hardware
key (RAID ADG Enabler Module) is missing or faulty, the write cache is
disabled and the user cannot configure any further RAID ADG volumes.
Customers who buy SA-5304/128 controllers will be able to download the
firmware upgrade to activate RAID ADG from the Compaq website at
www.compaq.com/smartarray.
Index
A
activating RAID ADG E-2
added security with online
spare C-1
Array Configuration Utility
assigning an online spare 3-6
changing cache read/write
ratio 3-7
source 3-4
assigning an online spare 3-6
available stripe size 3-8
Avis Canadien A-3
C
cabling
FCC compliance A-3
cache read/write ratio 3-7
Canadian Notice A-3
capacity of online spare 3-6
CE Marking A-4
changing the stripe size 3-9
choosing a RAID method 1-3
Compaq authorized reseller viii
Compaq website viii
comparing RAID failure rate C-1
comparison of RAID features 1-2
connector location 2-2
D
data rebuild time 3-6
Declaration of Conformity A-2
default stripe size 3-8
drive failure probability graph C-1
E
enabler module
appearance 2-3
description of 2-2
error messages D-1
European Union compliance
notice A-4
F
FCC (Federal Communications
Commission) notices A-1
firmware for activating RAID
ADG E-2
G
getting help vii
graph of drive failure
probability C-1
grounding methods B-2
2 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide Reference Guide
H
hard drives
maximum number per logical
drive C-1
help
additional sources vii
Compaq authorized resellers,
telephone numbers viii
Compaq website viii
technical support telephone
numbers vii
hot spare 3-5
I
icons
symbols on equipment vi
Important Safety Information
document vii
improving performance 3-7
J
Japanese notice A-4
L
likelihood of logical drive
failure C-1
logical drive failure
probability C-1
number of hard drives per logical
drive C-1
number of hard drives
supported C-1
number of online spares per
array 3-6
O
online spare 3-5, C-1
optimum stripe size 3-8
P
performance tuning 3-7
POST error messages D-1
precautions
installation 2-1
probability of logical drive
failure C-1
products supporting RAID
ADG E-2
R
RAID failure rate comparison C-1
RAID selection chart 1-3
RAID summary table 1-2
read/write ratio in cache 3-7
RJ-45 receptacle vi
S
M
maximum number of hard
drives C-1
migrating
stripe size 3-9
minimum capacity of online
spare 3-6
N
Network Interface Connection vi
NIC vi
safety information vii
static electricity B-1
stripe size
changing 3-8, 3-9
for given RAID method 3-8
optimum 3-8
summary of RAID features 1-2
supported number of hard
drives C-1
symbols in text vi
symbols on equipment vi
system performance
improving 3-7
Index 3
T
table
available stripe size 3-8
optimum stripe size 3-8
POST error messages D-1
RAID features 1-2
Taiwanese notice A-5
technical support vii
telephone numbers viii
text conventions v
tuning performance 3-7
W
warnings
electrical shock vii
installation 2-1
shutting down system 2-1
website, Compaq viii
Loading...