IBM 1269-3S2 Manual

IBM System Storage
DCS9900 1269-3S2 Storage Expansion
Unit Installation, Service, and User Guide
GA32-0613-00
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Contents
iii
1 Introduction ..................................................................................................................................... 1
1.1 IBM System Storage DCS9900 3S2 Storage Expansion Unit ..................................................... 1
1.2 Enclosure Core Product ............................................................................................................. 2
1.2.1 Enclosure Chassis .............................................................................................................. 2
1.3 The Plug-in Modules ................................................................................................................... 3
1.3.1 AC PSU/Cooling Module .................................................................................................... 3
1.3.2 Operator’s Panel ................................................................................................................ 4
1.3.3 EBOD Module .................................................................................................................... 5
1.3.4 Drive Carrier Module .......................................................................................................... 6
1.3.5 Dummy Carrier Modules .................................................................................................... 7
1.4 Visible and Audible Alarms .......................................................................................................... 7
1.5 IBM System Storage DCS9900 3S2 Storage Expansion Unit Technical Specification .............. 8
1.5.1 Dimensions ......................................................................................................................... 8
1.5.2 Weight ................................................................................................................................ 8
1.5.3 AC Power (450W PSU) ...................................................................................................... 8
1.5.4 PSU Safety and EMC Compliance ..................................................................................... 9
1.5.5 Power Cord ........................................................................................................................ 9
1.5.6 Environment ..................................................................................................................... 10
1.5.7 Interfaces .......................................................................................................................... 11
1.5.8 EBOD Module Specification ............................................................................................. 11
1.5.9 Drive Carrier Module Specification ................................................................................... 11
1.5.10 Software Enclosure Services (SES) Support ................................................................... 12
2 Getting Started .............................................................................................................................. 13
2.1 Planning Your Installation .......................................................................................................... 13
2.1.1 Enclosure Drive Bay Numbering Convention ................................................................... 14
2.2 Enclosure Installation Procedures ............................................................................................. 14
2.2.1 Pre-Requisites .................................................................................................................. 14
2.2.2 Chassis Installation .......................................................................................................... 15
2.3 Power Supply/Cooling Module Installation ................................................................................ 15
2.3.1 Parts Check List ............................................................................................................... 15
2.3.2 AC PSU/Cooling Module Installation Procedure .............................................................. 15
2.4 Connecting to the DCS9900 ...................................................................................................... 17
2.4.1 Connecting Multiple Enclosures ....................................................................................... 17
2.5 Partially Populated Enclosure ................................................................................................... 21
2.6 EBOD Module Installation ......................................................................................................... 21
2.6.1 Parts Check List ............................................................................................................... 21
2.6.2 Installation Procedure ....................................................................................................... 21
2.7 Drive Carrier Configuration ....................................................................................................... 22
2.7.1 Planning and Configuring Your Installation ...................................................................... 22
2.7.2 Parts Check List ............................................................................................................... 24
2.7.3 Installation Procedure ....................................................................................................... 25
2.7.4 Dummy Carrier Modules .................................................................................................. 27
2.7.5 Engaging the Anti-tamper Locks ...................................................................................... 27
2.8 Power Cord Connection ............................................................................................................ 28
2.8.1 Parts Check List ............................................................................................................... 28
2.8.2 Procedure ......................................................................................................................... 28
2.9 Grounding Checks ..................................................................................................................... 28
3 Operation ....................................................................................................................................... 29
3.1 Before You Begin ...................................................................................................................... 29

iv
3.2 Power On .................................................................................................................................. 29
3.2.1 PSU/Cooling Module LEDs .............................................................................................. 30
3.2.2 Ops Panel Switches ......................................................................................................... 30
3.2.3 Ops Panel LEDs .............................................................................................................. 31
3.3 Disk Drive LEDs ........................................................................................................................ 32
3.4 Power Down .............................................................................................................................. 32
4 Troubleshooting and Problem Solving ....................................................................................... 33
4.1 Overview ................................................................................................................................... 33
4.1.1 Initial Start-up Problems ................................................................................................... 33
4.2 Audible Alarm ............................................................................................................................ 34
4.2.1 Audible Alarm Mute .......................................................................................................... 34
4.3 LEDs ......................................................................................................................................... 35
4.3.1 PSU/Cooling Module ........................................................................................................ 35
4.3.2 Ops Panel ........................................................................................................................ 36
4.3.3 EBOD Module .................................................................................................................. 37
4.4 Troubleshooting ........................................................................................................................ 37
4.4.1 System Faults .................................................................................................................. 37
4.4.2 Power Supply/Cooling Faults ........................................................................................... 38
4.4.3 Thermal Control ............................................................................................................... 38
4.4.4 Thermal Alarm ................................................................................................................. 39
4.4.5 Thermal Shutdown ........................................................................................................... 40
4.5 Drive Carrier Module Faults ...................................................................................................... 41
4.5.1 Dummy Carrier Modules .................................................................................................. 41
4.6 Dealing with Hardware Faults ................................................................................................... 41
4.6.1 Ops Panel ........................................................................................................................ 41
4.7 Continuous Operation During Replacement ............................................................................. 42
4.8 Replacing a Module .................................................................................................................. 42
4.8.1 PSU/Cooling Modules ...................................................................................................... 42
4.8.2 EBOD Module .................................................................................................................. 44
4.8.3 Drive Carrier Module ........................................................................................................ 46
4.9 Spare Parts and Ancillary Items ............................................................................................... 46

IBM System Storage DCS9900 1269-3S2 Storage Expansion Unit Installation, Service, and User Guide #
Preface
What is in this guide
This guide gives you step-by-step instructions on how to install, configure, and connect this product to
your IBM DCS9900. In addition, it provides instructions on how to operate and service this product.
Who should use this guide
This guide assumes that you have a working knowledge of the SAS environment into which you are
attaching the product. If you do not have these skills, or are not confident with the instructions in this
guide, do not proceed with the installation.
NOTE : Not all information contained in the following sections will pertain directly to your particular
product model.
Getting information, help, and service
If you need help, service, or technical assistance or just want more information about IBM products, you
will find a wide variety of sources available from IBM to assist you. This section contains information
about where to go for additional information about IBM and IBM products, what to do if you experience
a problem with your IBM System Storage DCS9900 product, and whom to call for service, if it is
necessary.
Support information
For online support information for your IBM System Storage DCS9900 product, visit the following web
site:
www.ibm.com/support
For telephone support information, in the United States, contact IBM at 1-800-IBM-SERV (426-7378).
In other countries, visit the following web site for support telephone numbers:
www.ibm.com/planetwide/
Before you call
Before you call, make sure that you have taken these steps to try to solve the problem yourself:
• Check all cables on your hardware to make sure that they are connected properly.
• Check the power switches to make sure that the system is turned on.
• Use the troubleshooting information in your system documentation and use the diagnostic tools that
come with your system.
Using the documentation
Information about the DCS9900 product is available on a documentation CD that comes with your
product. You can also access documents using the IBM Publications Center:
http://www.ibm.com/shop/publications/order

vi IBM System Storage DCS9900 1269-3S2 Storage Expansion Unit Installation, Service, and User Guide
International Standards
This product complies with the applicable Information Technology (IT) standards set forth by EMC and
product safety for world wide shipment.
Qualified Personnel
The personnel qualified to use this device are referred to within this document as follows:
•Service Person: Someone with the appropriate and necessary technical training and experience to be
aware of hazards to which they may be exposed in performing a task and of measures to minimize the
risks to that person or other persons.
•User/Operator: Any person authorized to handle/operate the product other than a Service Person.
Delivery and Subsequent Transportation of the Equipment
You must prepare your environment to accept the new product based on the installation planning information
provided, with assistance from an IBM Installation Planning Representative (IPR) or IBM authorized service
provider. In anticipation of the equipment delivery, prepare the final installation site in advance so that
professional movers or riggers can transport the equipment to the final installation site within the computer
room. If for some reason, this is not possible at the time of delivery, you must make arrangements to have
professional movers or riggers return to finish the transportation at a later date. Only professional movers or
riggers should transport the equipment. The IBM authorized service provider can only perform minimal frame
repositioning within the computer room, as needed, to perform required service actions. You are also
responsible for using professional movers or riggers when you relocate or dispose of equipment.
Rack Relocation
Observe the following precautions when you need to relocate your rack:
• Before you add or remove drawers, always lower the leveling feet and install the anti-tip plates, or have
the rack bolted to the floor.
• Always install drawers at the bottom of the rack first.
• Always remove drawers from the top of the rack first.
• Always install the heaviest drawers on the bottom of the rack.
• Never push on the sides of the rack.
• When relocating the DCS9900 rack with 1269-3S1 draws installed, the hard drives installed in the
drawers must be removed to avoid a side-to-side tip-over hazard.
Safe Handling
Do not try to lift the enclosure by yourself. An enclosure can weigh from 9 kg (19.8 lb) to 37 kg (77.6 lb).
Before removing an enclosure from a rack cabinet, always first remove all modules and drives from the
enclosure to minimize weight.
Figure P-1 Danger (D006) Heavy Equipment Label

IBM System Storage DCS9900 1269-3S2 Storage Expansion Unit Installation, Service, and User Guide vii
Figure P-2 2 Man Lift Safety Label
Do not try to lift the enclosure by the handles on the PSU/Cooling module. The handles are not
designed to support the weight of the populated enclosure.
Figure P-3 Weight Handling Label: Lifting and Tipping
Figure P-4 Pinch Hazard Label: Keep Hands Clear

viii IBM System Storage DCS9900 1269-3S2 Storage Expansion Unit Installation, Service, and User Guide
Safety Guidelines
Caution ! If this product is used in a manner not specified by the manufacturer, the protection provided by
the product may be impaired.
• The product can weigh up to 35 kg (77 lb). Do not try to lift it by yourself.
Figure P-5 Chassis Warning Label: Weight Hazard
Caution ! Plug-in modules are part of the fire enclosure and must only be removed when a replacement can
be immediately added. The system must not be run without all units in place. Operate the system
with the enclosure top cover closed and blanking plates fitted where modules are missing.
• To comply with applicable safety, emission, and thermal requirements, keep all enclosure covers securely
fitted and keep all bays fitted with plug-in modules.
• Enclosures must be only operated from a power supply input voltage range of 100 V AC to 240 V
AC.When a redundant power input module is fitted, it must be operated from a reduced input voltage
range of 200 V AC to 240 V AC.
• The plug on the power supply cord is used as the main disconnect device. Ensure that the socket outlets
are located near the product and are easily accessible.
• The product is intended to operate with three (3) working PSUs. Before the removal or replacement of
any module, disconnect all supply power for complete isolation.
The enclosure MUST be grounded before applying power.
Permanently unplug the product if you think that it has
become damaged in any way and before you move it.
!
Warning
!
Warning

IBM System Storage DCS9900 1269-3S2 Storage Expansion Unit Installation, Service, and User Guide ix
Figure P-6 PSU/Cooling Module Caution Label: Do not operate with modules missing.
• A faulty power supply/cooling module must be replaced with a fully operational module within 24
hours.
• Do not remove a faulty power supply/cooling module unless you have a correct replacement product
ready for insertion.
Figure P-7 PSU Warning Label (Power Hazards)
• Always disconnect power to the product prior to removal of the power supply/cooling module from
the product chassis.
• When powered by multiple AC sources, disconnect all supply power for complete isolation.
• Provide a safe electrical earth (ground) connection for the power cord. Check the grounding of the
enclosure before applying power.
• Provide a suitable power source with electrical overload protection to meet the requirements detailed
in the product’s technical specifications.
To ensure protection against electric shock caused by HIGH
LEAKAGE CURRENT (TOUCH CURRENT), the enclosure
must be connected to at least two separate and independent
sources. This should ensure a reliable earth connection.
To ensure your system has warning of a power failure,
disconnect the power from the PSU by either the switch
(where present) or by physically removing the power source,
prior to removing the PSU from the enclosure.
!
Warning
!
Warning

x IBM System Storage DCS9900 1269-3S2 Storage Expansion Unit Installation, Service, and User Guide
Figure P-8 PSU Safety Label (Electric Shock Hazard Inside)
Figure P-9 Redundant Power Input Switch Module Label (Hazardous Voltage)
Do not remove covers from the Power Supply Unit (PSU).
Danger of electric shock inside. Return the damaged PSU to
your supplier for repair.
Operation of the product with ANY modules MISSING in the
product’s chassis will disrupt airflow and the drives will not
receive sufficient cooling. It is ESSENTIAL that all bays in a
product chassis are filled before operating the product.
!
Warning
!
Warning

IBM System Storage DCS9900 1269-3S2 Storage Expansion Unit Installation, Service, and User Guide xi
Figure P-10 I/O Module Caution Label (Do not operate with modules missing)
Figure P-11 Drive Carrier Module Caution Label (Drive Spin down time 30 seconds)
• Do not operate with modules missing.
Class 1 Laser Product
When the product is supplied with optical modules, it contains a laser that complies with Laser Class 1,
US 21 QFR (J) & EN 60825-1, UL (NRTL) and TUV.
Caution ! If optical modules are to be provided and fitted by the end user, the modules must be a UL (or
other North American NRTL) RECOGNISED COMPONENT, must be approved by TUV (or
other European Product safety test house), and the laser in the module must comply with
Laser Class 1, US 21 QFR (J) & EN 60825-1.
Important ! Observe all applicable safety precautions (for example, weight restrictions, handling
batteries and lasers etc.) detailed in the preceding paragraphs when dismantling and
disposing of this product or its components.
European Regulations
This equipment complies with European Regulations EN 55022 Class A: Limits and Methods of
Measurement of Radio Disturbance Characteristics of Information Technology Equipments and
EN50082-1: Generic Immunity.
Special Tools and Equipment
There are no special tools required, but in order to complete the assembly of some configurations, you
may need the following (not supplied):
• Security keys (one of these should be included with your IBM System Storage DCS9900 3S2
Storage Expansion Unit for use with the drive locks).
Electronic Emission Notices
The following statements apply to this product. The statements for other products intended for use with
this product will appear in their accompanying manuals.

xii IBM System Storage DCS9900 1269-3S2 Storage Expansion Unit Installation, Service, and User Guide
Federal Communications Commission (FCC) Class A Statement
NOTE : 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 instruction manual, 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 his own expense.
Properly shielded and grounded cables and connectors must be used in order to meet FCC emission limits.
IBM is not responsible for any radio or television interference caused by using other than recommended cables
and connectors or by unauthorized changes or modifications to this equipment. Unauthorized changes or
modifications could void the user’s authority to operate the equipment.
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.
Industry Canada Class A Emission Compliance Statement
This Class A digital product complies with Canadian ICES-003.
Avis de conformité à la réglementation d’Industrie Canada
Cet appareil numérique de la classe A est conform à la norme NMB-003 du Canada.
European Union (EU) Electromagnetic Compatibility Directive
This product is in conformity with the protection requirements of EU Council Directive 2004/108/EC on the
approximation of the laws of the Member States relating to electromagnetic compatibility. IBM cannot accept
responsibility for any failure to satisfy the protection requirements resulting from a non-recommended
modification of the product, including the fitting of non-IBM option cards.
This product has been tested and found to comply with the limits for Class A Information Technology
Equipment according to European Standard EN 55022. The limits for Class A equipment were derived for
commercial and industrial environments to provide reasonable protection against interference with licensed
communication equipment.
Attention: This is a Class A product. In a domestic environment this product may cause radio interference in
which case the user may be required to take adequate measures.
Properly shielded and grounded cables and connectors must be used in order to reduce the potential for causing
interference to radio and TV communications and to other electrical or electronic equipment. Such cables and
connectors are available from IBM authorized dealers. IBM cannot accept responsibility for any interference
caused by using other than recommended cables and connectors.
European Community contact:
IBM Technical Regulations
Pascalstr. 100, Stuttgart, Germany 70569
Tele: 0049 (0)711 7851176
Fax: [phone]
e-mail: [email protected]

IBM System Storage DCS9900 1269-3S2 Storage Expansion Unit Installation, Service, and User Guide xiii
Australia and New Zealand Class A Statement
Attention: This is a Class A product. In a domestic environment this product may cause radio interference
in which case the user may be required to take adequate measures.
Germany Electromagnetic Compatibility Directive
Deutschsprachiger EU Hinweis:
Hinweis für Geräte der Klasse A EU-Richtlinie zur Elektromagnetischen Verträglichkeit
Dieses Produkt entspricht den Schutzanforderungen der EU-Richtlinie 2004/108/EG zur Angleichung
der Rechtsvorschriften über die elektromagnetische Verträglichkeit in den EU-Mitgliedsstaaten und hält
die Grenzwerte der EN 55022 Klasse A ein.
Um dieses sicherzustellen, sind die Geräte wie in den Handbüchern beschrieben zu installieren und zu
betreiben. Des Weiteren dürfen auch nur von der IBM empfohlene Kabel angeschlossen werden. IBM
übernimmt keine Verantwortung für die Einhaltung der Schutzanforderungen, wenn das Produkt ohne
Zustimmung der IBM verändert bzw. wenn Erweiterungskomponenten von Fremdherstellern ohne
Empfehlung der IBM gesteckt/eingebaut werden.
EN 55022 Klasse A Geräte müssen mit folgendem Warnhinweis versehen werden:
"Warnung: Dieses ist eine Einrichtung der Klasse A. Diese Einrichtung kann im Wohnbereich Funk-
Störungen verursachen; in diesem Fall kann vom Betreiber verlangt werden, angemessene Maßnahmen
zu ergreifen und dafür aufzukommen."
Deutschland: Einhaltung des Gesetzes über die elektromagnetische Verträglichkeit von Geräten
Dieses Produkt entspricht dem "Gesetz über die elektromagnetische Verträglichkeit von Geräten
(EMVG)". Dies ist die Umsetzung der EU-Richtlinie 2004/108/EG in der Bundesrepublik Deutschland.
Zulassungsbescheinigung laut dem Deutschen Gesetz über die elektromagnetische Verträglichkeit
von Geräten (EMVG) (bzw. der EMC EG Richtlinie 2004/108/EG) für Geräte der Klasse A
Dieses Gerät ist berechtigt, in Übereinstimmung mit dem Deutschen EMVG das EG-
Konformitätszeichen - CE - zu führen.
Verantwortlich für die Konformitätserklärung des EMVG ist die IBM Deutschland GmbH, 70548
Stuttgart.
Generelle Informationen:
Das Gerät erfüllt die Schutzanforderungen nach EN 55024 und EN 55022 Klasse A.
People’s Republic of China Class A Electronic Emission Statement

xiv IBM System Storage DCS9900 1269-3S2 Storage Expansion Unit Installation, Service, and User Guide
Taiwan Class A Warning Statement
Japan VCCI Class A ITE Electronic Emission Statement
Korean Class A Electronic Emission Statement
Taiwan Contact Information

IBM System Storage DCS9900 1269-3S2 Storage Expansion Unit Installation, Service, and User Guide xv
Rack System Precautions
The following safety requirements must be considered when the product is mounted in a rack:
• The rack design should incorporate stabilizing features suitable to prevent the rack from tipping or
being pushed over during installation or in normal use.
• When loading a rack with the units, fill the rack from the bottom up and empty from the top down.
• System must be operated with low pressure rear exhaust installation. (Back pressure created by rack
doors and obstacles should not exceed 5 pascals [0.5mm Water gauge].)
• The rack design should take into consideration the maximum operating ambient temperature for the
unit, which is 32°C.
• The rack should have a safe electrical distribution system. It must provide overcurrent protection for
the unit and must not be overloaded by the total number of units installed in the rack. Consideration
of the electrical power consumption rating shown on the nameplate should be used when addressing
these concerns.
• The electrical distribution system must provide a reliable earth grounding for each unit and the rack.
• Each power supply in each unit has an earth leakage current of 1.8mA. The design of the electrical
distribution system must take into consideration the total earth leakage current from all the power
supplies in all the units. The rack will require labelling with “HIGH LEAKAGE CURRENT. Earth
connection essential before connecting supply”.
• The rack when configured with the units must meet the safety requirements of UL 60950 and IEC
60950.
ESD Precautions
Caution ! It is recommended that you wear a working (examine before wearing) anti-static wrist or
ankle strap and observe all conventional ESD precautions when handling Chassis slug-in
modules and components. Avoid contact with backplane components, module connectors,
etc.
Do not slide more than one product enclosure chassis out of the
rack at a time, to avoid the rack from toppling over.
!
Warning

xvi IBM System Storage DCS9900 1269-3S2 Storage Expansion Unit Installation, Service, and User Guide
Data Security
• Before beginning product installation, power down your DCS9900 and all attached peripheral devices.
• Disk drives are fragile. Handle them with care, and keep them away from strong magnetic fields.
•All the supplied plug-in modules and blanking plates must be in place for the air to flow correctly around
the enclosure and to complete the internal circuitry.
• If the subsystem is used with modules or blanking plates missing for more than a few minutes, the
enclosure can overheat, causing power failure and data loss.
• If you remove any drive module, you may lose data.
• If you remove a drive module, replace it immediately. Replace it with a drive module of the same type
and capacity
• Do not abandon your backup routines. No system is completely foolproof.
How to Send Your Comments
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using the following address:
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Introduction
1
Chapter 1
Introduction
1.1 IBM System Storage DCS9900 3S2
Storage Expansion Unit
The IBM System Storage DCS9900 3S2 Storage Expansion Unit is based on an enclosure system
incorporating 16 drive bays designed to support SAS disk drives.
The subsystem utilizes Low Profile,1 inch high, 3.5 inch form factor disk drives (Figure 1–1).
.
Figure 1–1 Storage Subsystem Enclosure

IBM System Storage DCS9900 1269-3S2 Storage Expansion Unit Installation, Service, and User Guide
2
1.2 Enclosure Core Product
The IBM System Storage DCS9900 3S2 Storage Expansion Unit design concept is based on a
subsystem together with a set of plug-in modules. The IBM System Storage DCS9900 3S2 Storage
Expansion Unit as supplied comprise:
• Up to 16 Drive Carrier Modules (Figure 1–2)
•Chassis and Backplane with integral Operators Panel.(Figure 1–2)
•Dummy Drive Carrier Modules (as required)
• Two (2) plug-in Power Supply/Cooling Modules, (.AC, 450W (Figure 1–3)
• Two (2) plug-in EBOD (Expanded Bunch of Disks) Serial Controller (EM) Modules. (Figure 1–6).
1.2.1 Enclosure Chassis
The chassis consists of a sheet metal enclosure assembly containing a Backplane Printed Circuit Board
(PCB) and module runner system. This chassis assembly also includes an integral Operators (Ops)
Panel, mounted at the rear.
The chassis assembly contains 16 drive bays at the front, each of which accommodates a plug-in drive
carrier module. The 16 drive bays are arranged in 4 rows of 4 drives. At the rear, the chassis assembly
contains the integral Ops Panel module and four plug-in module bays to house two Power Supply/Cooling
modules and two EBOD modules.
The Backplane PCB provides logic level signal and low voltage power distribution paths. Figure 1–2
shows typical front and rear views of an IBM System Storage DCS9900 3S2 Storage Expansion Unit
chassis assembly.
The chassis is fitted with 19 inch rack mounting features which enables it to be fitted to standard 19 inch
racks and uses 3 EIA units of rack space.
Note A drive bay is defined as the space required to house a single 1.0" high 3.5 inch disk drive in its carrier
module. For example, a 1 x 4 bay module would take the space of 1 drive width by 4 drive bays high (in
rack mount configuration). A 4 x 4 bay module is shown in Figure 1–2.
Figure 1–2 Enclosure Chassis (Front and Rear Views)

Introduction
3
1.3 The Plug-in Modules
The IBM System Storage DCS9900 3S2 Storage Expansion Unit requires the following modules for
normal operation:
• 2 x Power Supply/Cooling modules
• 2 x EBOD modules
• Up to 16 SAS drive carrier modules and/or dummy drive carrier modules, as required.
Note No drive bays should be left completely empty.
1.3.1 AC PSU/Cooling Module
Two (2) auto ranging AC 450W PSU/Cooling modules are supplied mounted in the rear of the enclosure
as part of the subsystem core product.
The PSU voltage operating ranges are nominally 115V or 230V AC, selected automatically. Four LEDs
mounted on the front panel of the Power Supply/Cooling module (Figure 1–3) indicate the status of the
PSU and the fans.
1.3.1.1 Multiple Power Supply/Cooling Modules
The IBM System Storage DCS9900 3S2 Storage Expansion Unit must always be operated with two
Power Supply (PSU)/Cooling modules fitted. The two PSU/Cooling modules operate together so that if
one fails the other maintains the power supply and cooling while you replace the faulty unit.
Module replacement should only take a few minutes to perform but must be completed within 10 minutes
from removal of the failed module.
Figure 1–3 AC Power Supply/Cooling Module (reverse orientation at installation)

IBM System Storage DCS9900 1269-3S2 Storage Expansion Unit Installation, Service, and User Guide
4
1.3.2 Operator’s Panel
Supplied as an integral part of the enclosure core product, a typical Operator’s (Ops) Panel is shown in
Figure 1–4.
The Ops Panel provides the enclosure with a micro-controller which is used to monitor and control all
elements of the enclosure.
1.3.2.1 Ops Panel Indicators and Switches
The Ops Panel includes Light Emitting Diodes (LEDs) which show the status for all modules (shown in
Table 3–1 on page 31), an Audible Alarm which indicates when a fault state is present, a push-button
Alarm Mute Switch, and a thumb wheel Enclosure ID switch which is not used in this configuration.
Figure 1–4 Ops Panel