Rorke Data Galaxy HDX4 16 Bay RAID User manual

Installation and Hardware
Reference Manual
ISO 9001:2008
ISO 13485:2003 Certified
www.rorke.com
Galaxy HDX4 16 Bay RAID
Galaxy HDX4 24 Bay RAID
1GbE iSCSI Host SAS / SATA Drives
7th Generation Fibre Channel RAID
With over 10,000 Galaxy units in the field, Rorke Data’s award
winning RAID products provide the performance, protection,
and expansion capabilities for diverse customer environments.
PLEASE READ BEFORE INSTALLATION
MODELS:
16 BAY 1GbE iSCSI to SAS/
SATA II RAID Subsystem
Single / Dual Controller
24 BAY 1GbE iSCSI to SAS/
SATA II RAID Subsystem
Single / Dual Controller
Rorke Data, An Avnet Company
7626 Golden Triangle Drive, Eden Prairie, MN 55344, USA
» Toll Free 1.800.328.8147 » Phone [phone] » Fax [phone]
Galaxy®HDX4
GX4L_16_24i_1GbE_0811_HMN

Table of Content
Table of Content............................................................................................1
Copyright 2010 ..............................................................................................5
This Edition First Published 2010..............................................................................5
Disclaimer..................................................................................................................5
Trademarks ...............................................................................................................5
Warnings and Certifications ......................................................................................6
FCC Class B Radio Frequency Interference Statement ...........................................6
Safety Precautions........................................................................................9
Precautions and Instructions.....................................................................................9
ESD Precautions..............................................................................................................10
Revision History.......................................................................................................10
Who should read this manual?................................................................................10
Related Documentation....................................................................................................10
Conventions.............................................................................................................10
Software and Firmware Updates.............................................................................11
Chapter 1 Introduction................................................................................12
Product Overview....................................................................................................12
Introduction.......................................................................................................................12
Enclosure Chassis............................................................................................................13
Subsystem Components .........................................................................................16
Drive Trays.......................................................................................................................16
MUX Kit ............................................................................................................................17
The RAID Controller Module ............................................................................................18
Controller Module Interfaces ............................................................................................19
DIMM Module...................................................................................................................20
Battery Backup Module ....................................................................................................20
Power Supply Units..........................................................................................................21
Cooling Modules...............................................................................................................21
Subsystem Monitoring.............................................................................................22
Hot-swappable Components...................................................................................23
Hot-swap Capabilities.......................................................................................................23
Components.....................................................................................................................23
Normalized Airflow ...........................................................................................................23
Chapter 2 Hardware Installation.................................................................24
Introduction..............................................................................................................24
Installation Prerequisites .........................................................................................24
Safety Precautions ..................................................................................................26
Precautions and Instructions............................................................................................26
Static-free Installation.......................................................................................................28
General Installation Procedure................................................................................28
Installation Procedure Flowchart......................................................................................29
Unpacking the Subsystem.......................................................................................30
Preinstalled Components .................................................................................................30
Components to be Installed..............................................................................................31
Rack/Cabinet Installation.........................................................................................31
Package Contents............................................................................................................31
Installation Pre-requisites.................................................................................................32
Rack-mounting Steps.......................................................................................................32
BBU and FBM Installation .......................................................................................36
BBU Module Installation Overview...................................................................................36
BBU Warnings and Precautions.......................................................................................36
BBU Installation Procedure ..............................................................................................36
FBM (Flash Backup Module) Installation Procedure ........................................................38

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
2
Hard Drive Installation.............................................................................................38
Hard Drive Installation Prerequisites................................................................................38
Drive Installation...............................................................................................................39
Drive Tray Installation.......................................................................................................40
Chapter 3 Subsystem Monitoring...............................................................43
Overview..................................................................................................................43
Status-indicating LEDs............................................................................................44
LCD Keypad Panel...........................................................................................................44
Drive Tray LEDs...............................................................................................................45
Controller Module LEDs ...................................................................................................46
How to Use the Restore Default Button?..........................................................................48
Why restore defaults? ......................................................................................................48
Ethernet Port LEDs ..........................................................................................................49
PSU LEDs........................................................................................................................51
Cooling Module LEDs.......................................................................................................51
Audible Alarm..........................................................................................................52
Failed Devices..................................................................................................................53
I2C ....................................................................................................................................53
Chapter 4 Subsystem Connection and Operation.....................................54
Connection Overview ..............................................................................................54
Cabling.............................................................................................................................54
Network Topologies..........................................................................................................55
Points of Failure ...............................................................................................................55
Host Connection Topologies ............................................................................................55
Sample Topology – Single-controller with Fault-tolerant Paths........................................58
Sample Topology – Single-Controller with Trunks............................................................59
Sample Topology – High Availability IP SAN with Redundant RAID Controllers..............60
iSCSI Topology and Host LUN Mapping:.........................................................................62
Expansion Links ......................................................................................................63
Single-controller RAID to single-controller JBOD.............................................................63
Dual-controller RAID to dual-controller JBOD. .................................................................64
Enclosure ID and Other Concerns....................................................................................65
Powering On............................................................................................................66
Check List.........................................................................................................................67
Power-On Procedure........................................................................................................67
Power-On Enclosure........................................................................................................68
Power-On Status Check...................................................................................................68
Power Off Procedure...............................................................................................69
Chapter 5 Subsystem Maintenance and Upgrading...............................70
Overview..................................................................................................................70
Maintenance.....................................................................................................................70
General Notes on Component Replacement....................................................................70
Replacing a Controller Module................................................................................72
Overview ..........................................................................................................................72
Notes on Controller Maintenance.....................................................................................72
Removing the Controller Module......................................................................................72
Replacing the Controller Module......................................................................................74
Replacing or Upgrading Memory Modules..............................................................75
Memory Module Installation Overview..............................................................................75
Selecting Memory Modules..............................................................................................75
DIMM Module Installation.................................................................................................76
Replacing a Faulty BBU ..........................................................................................77
Fault Conditions: ..............................................................................................................77
BBU Warnings and Precautions.......................................................................................77
Replacing a Faulty BBU...................................................................................................78
Replacing a Faulty Flash Backup Module (FBM) .............................................................79
Replacing a Faulty PSU ..........................................................................................80
Notes on PSU Module Maintenance ................................................................................80
Replacing the PSU Module..............................................................................................81

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
3
Cooling Module Maintenance..................................................................................83
Notes on Cooling Module Maintenance............................................................................83
Replacing a Cooling Module.............................................................................................84
For 3U 16 bay models:.....................................................................................................84
For 4U 24 bay models:.....................................................................................................84
Replacing a Hard Drive ...........................................................................................85
Hard Drive Maintenance Overview...................................................................................85
Replacing a Hard Drive ....................................................................................................86
Appendix A Specifications .........................................................................88
Technical Specifications..........................................................................................88
Controller Specifications..........................................................................................91
Configuration....................................................................................................................91
Architecture......................................................................................................................91
Power Supply Specifications...................................................................................92
RAID Management..................................................................................................93
Fault Tolerance Management .................................................................................93
Appendix B Pinouts..................................................................................95
B.1 GbE Ethernet Port Pinouts (iSCSI Host Ports) ............................................95
B.2 Ethernet Management Port Pinouts.............................................................96
B.3 DB-9 Serial Port..........................................................................................96
B.4 SAS Expansion Port Pinouts........................................................................97
B.5 Power ...........................................................................................................97

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
4
Contact Information
Contact Information
Americas
Rorke Data , An Avnet company
7626 Golden Triangle Drive
Eden Prairie, MN 55344
USA
Tel: [phone]
Fax: [phone]
rork[email protected]
rork[email protected]om
http://www.rorke.com

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
5
Copyright 2011
This Edition First Published 2011
All rights reserved. This publication may not be reproduced, trans-
mitted, transcribed, stored in a retrieval system, or translated into any
language or computer language, in any form or by any means, elec-
tronic, mechanical, magnetic, optical, chemical, manual or otherwise,
without the prior written consent of Rorke Data.
Disclaimer
Rorke Data makes no representations or warranties with respect to
the contents hereof and specifically disclaims any implied warranties
of merchantability or fitness for any particular purpose. Furthermore,
Rorke Data reserves the right to revise this publication and to make
changes from time to time in the content hereof without obligation to
notify any person of such revisions or changes. Product
specifications are also subject to change without prior notice.
Trademarks
Galaxy and the Galaxy logo are registered trademarks of Rorke
Data..
Solaris and Java are trademarks of Sun Microsystems, Inc.
All other names, brands, products or services are trademarks or
registered trademarks of their respective owners..

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
6
Warnings and Certifications
Restricted Access Location:
This equipment is intended to be installed in a RESTRICTED
ACCESS LOCATION only.
Electric Shock Warning!
To Prevent Electric Shock:
Access to this equipment is granted only to trained operators and
service personnel who have been instructed of and fully understand
the possible hazardous conditions and the consequences of
accessing non-field-serviceable units. For example, touching the
backplane with a metal tool may cause electric shock.
FCC (applies in the U.S. and Canada)
FCC Class B Radio Frequency Interference
Statement
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 may accept any interference
received, including interference that may cause undesired operation.
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.
Any changes or modifications not expressly approved by the party
responsible for compliance could void the user’s authority to operate
the equipment.

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
7
WARNING:
A shielded power cord is required in order to meet FCC emission
limits and also to prevent interference to nearby radio and television
reception.
Use only shielded cables to connect I/O devices to this equipment.
You are cautioned that changes or modifications not expressly
approved by the party responsible for compliance could void your
authority to operate the equipment.
This device is in conformity with the EMC.
CB
(Certified Worldwide)
This device meets the requirements of the CB standard for
electrical equipment with regard to establishing a satisfactory
level of safety for persons using the device and for the area
surrounding the apparatus. This standard covers only safety
aspects of the above apparatus; it does not cover other
matters, such as style or performance.
CCC
For Power Supplies’ compatibility to China Compulsory
Certification.
China RoHS
In Compliance with AeA China RoHS Regulations (SJ/T 11364-2006)
ITE BSMI Class A,
CNS 13438
(for Taiwan)

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
8
This device is in conformity with UL standards for safety.
Инструкция по безопасности
Модель:
iSCSI to SAS/SATA 3U/16 and 4U/24 Bay RAID Subsystem,. and no impact
safety related critical components and constructions.
1. Перед использованием оборудования внимательно прочтите
инструкцию.
2. Сохраняйте инструкцию для дальнейшего использования в работе.
3. Не допускайте попадания влаги на изделие.
4. Устанавливайте оборудование на устойчивую поверхность.
Падение может нанести ущерб оборудованию.
5. Соблюдайте климатические требования, использование
оборудование при температуре окружающей среды выше 50°С,
может привести к выходу оборудования из строя.
6. Размещайте шнур питания в недоступном для пользователя месте.
Запрещается ставить на шнур питания какие-либо предметы.
7. При работе с оборудованием необходимо учитывать все
предупреждения и замечания.
8. Если оборудование не используется в течении длительного
времени, отключите его от сети питания.
9. Запрещается вскрывать оборудование. Оборудование может
вскрываться только квалифицированным персоналом.
10. При возникновении одного из повреждений оборудования вызовите
обслуживающий персонал:
a.Повреждение шнура питания или вилки.
b.Оборудование не работает или его работа не соответствует
инструкции пользователя .
e.Оборудование повреждено.
f. Оборудование имеет очевидный признак поломки.
11. Источник питания должен быть установлен в соответствии с
инструкцией. Ток нагрузки и выходная мощность не должны
превышать указанных в спецификации.
We are committed to being properly prepared and taking all
the necessary steps that will result in our compliance with the
new European directive, RoHS (2002/95/EC), on or before
the specific dates set forth in those applicable laws and
regulations. Rorke is applying its own internal efforts and
expertise and is working closely with customers and suppliers
to achieve compliance while maintaining an uninterrupted
supply of quality products. Rorke is currently investigating,
evaluating, and qualifying our materials and components to
ensure that products sold on or after 1 July 2006, in such
territory, are in compliance with the above regulations.

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
9
Disposal of Old Electrical & Electronic Equipment (Applicable
in the European Union and other European countries with
separate collection systems)
This symbol on the product or on its packaging indicates that
this product shall not be treated as household waste. Instead
it shall be handed over to the applicable collection point for
the recycling of electrical and electronic equipment. By proper
waste handling of this product you ensure that it has no
negative consequences for the environment and human
health, which could otherwise be caused if this product is
thrown into the garbage bin. The recycling of materials will
help to conserve natural resources.
For more details about recycling of this product, please
contact your local city office, your household waste disposal
service or the shop where you purchased the product.
Safety Precautions
Precautions and Instructions
•Prior to powering on the subsystem, ensure that the correct power range
is being used.
•If it is necessary to transport the subsystem, repackage all disk drives
separately in the drive trays and in the original package foam blocks. If
using the original package material, other replaceable modules can stay
within the enclosure.
•The Galaxy subsystem comes with 16 / 24 drive bays. Leaving any of
these drive bays empty will greatly affect the efficiency of the airflow
within the enclosure, and will consequently lead to the system
overheating, which can cause irreparable damage.
•If a module fails, leave it in place until you have a replacement unit and
you are ready to replace it.
•Airflow Consideration: The subsystem requires an airflow clearance,
especially at the front and rear. A clearance of at least 18 to 20
centimeters is required at the rear side and any objects blocking the
exhaust airflow, e.g., cables dangling at the fan outlet, should be avoided.
•Handle subsystem modules using the retention screws, eject levers, and
the metal frames/face plates. Avoid touching PCB boards and connector
pins.
•To comply with safety, emission, or thermal requirements, none of the
covers or replaceable modules should be removed. Make sure that all
enclosure modules and covers are securely in place during operation.
•Be sure that the rack cabinet into which the subsystem chassis will be
installed provides sufficient ventilation channels and airflow circulation
around the subsystem.

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
10
•Provide a soft, clean surface to place your subsystem on before working
on it. Servicing on a rough surface may damage the exterior of the
chassis.
•If it is necessary to transport the subsystem, repackage all drives
separately.
•Dual-redundant controller models come with two RAID controllers that
should always be present. Single-controller models come with a single
RAID controller and a metal sheet is placed over the lower controller bay
at the rear of the subsystem. Since single-controller models cannot be
upgraded, this metal sheet should NEVER be removed.
ESD Precautions
Observe all conventional anti-ESD methods while handling system
modules. The use of a grounded wrist strap and an anti-static work
pad are recommended. Avoid dust and debris in your work area.
Revision History
Rev. 1.0: Initial release.
Who should read this manual?
This manual assumes that its readers are experienced with computer
hardware installation and are familiar with storage enclosures.
Related Documentation
•Generic Operation Manual (firmware operation via LCD keypad
or terminal emulation)
•Galaxy Array Manager User’s Manual
These two (2) documents are included in the product utility CD that
came with your subsystem package.
Conventions
Naming
From this point on and throughout the rest of this manual, the Galaxy
series is referred to as simply the “subsystem” or the “system” and
Galaxy is frequently abbreviated as “HDX4”
Important Messages
Important messages appear where mishandling of components is
possible or when work order can be mis-conceived. These
messages also provide important information associated with other
aspects of system operation. The word “important” is written as
“IMPORTANT,” both capitalized and bold and is followed by text in
italics. The italicized text is the message to be delivered.

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
11
Warnings
Warnings appear where overlooked details may cause damage to the
equipment or result in personal injury. Warnings should be taken
seriously. Warnings are easy to recognize. The word “warning” is
written as “WARNING,” both capitalized and bold and is followed by
text in italics. The italicized text is the warning message.
Cautions
Cautionary messages should also be heeded to help you reduce the
chance of losing data or damaging the system. Cautions are easy
to recognize. The word “caution” is written as “CAUTION,” both
capitalized and bold and is followed by text in italics. The italicized
text is the cautionary message.
Notes
These messages inform the reader of essential but non-critical
information. These messages should be read carefully as any
directions or instructions contained therein can help you avoid
making mistakes. Notes are easy to recognize. The word “note” is
written as “NOTE,” both capitalized and bold and is followed by text
in italics. The italicized text is the cautionary message.
Lists
Bulleted Lists: Bulleted lists are statements of non-sequential facts.
They can be read in any order. Each statement is preceded by a
round black dot “•.”
Numbered Lists: Numbered lists are used to describe sequential
steps you should follow in order.
Software and Firmware Updates
Please contact your system vendor for the latest software or firmware
updates. NOTE that the firmware version installed on your system
should provide the complete functionality listed in the specification
sheet/user’s manual. We provide special revisions for various
application purposes. Therefore, DO NOT upgrade your firmware
unless you fully understand what a firmware revision will do.
Problems that occur during the updating process may cause
irrecoverable errors and system down time. Always consult technical
personnel before proceeding with any firmware upgrade.

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
12
Chapter 1
Introduction
Product Overview
Introduction
This chapter briefly introduces the Galaxy iSCSI-to-SAS/SATA-II 16
bay and 24 bay storage subsystem. The Galaxy iSCSI subsystem
comes with four (4) Gigabit
Ethernet host ports on each
RAID controller and two on
the motherboard to deliver
fast I/O performance over
iSCSI packets.
Rorke’s iSCSI storage
supports network initiators
compatible with the IETF
(Internet Storage Name
Server) iSCSI standard (RFC
3720) with the following
functionality:
Access control via
NetMask, IQN, and IP filtering
iSNS & SLP device discovery (firmware rev. 3.64)
CHAP access control security
Jumbo frames
Header Digest mode (for the redundant-controller)
Internet SCSI (iSCSI) protocols are embedded in firmware and I/Os
are rapidly processed via dedicated algorithms. The 16 bay is built
around reliable hardware and sophisticated RAID technologies. I/O
requests are packaged and transmitted over local area networks
(LANs), wide area networks (WANs), or the Internet using the
existing Ethernet network and thus the total cost of ownership is
reduced. With the help of the networking flexibility, the subsystem is
ideal for location-independent data storage, backup, and retrieval.
The subsystem delivers extreme performance that results from the
combined performance of multiple disk drives and the level of data
protection unseen in other iSCSI storages. Featuring all standard
RAID functionality as other Galaxy subsystems, the subsystem
provides a reliable platform for IT operations such as backup, data-
mining, or strategic data allocation.
Figure 1-1: Galaxy 16 bay (top) and
Galaxy 24 bay (bottom)

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
13
This subsystem features a high-density architecture that supports hot
swappable SAS or SATA-II hard drives. The subsystem is powered
by active-active or a single RAID controller featuring the latest
ASIC667 RAID engine. The pre-installed 2GB DDR-II RAM DIMM
module can be upgraded to a 4GB capacity DIMM.
In addition to the ease of implementation, the iSCSI version of the
Galaxy also supports capacity expansion via its SAS links by
attaching JBODs.
The Galaxy features high-availability design with dual-active RAID
controllers. Dual-redundant, hot-swappable cooling modules, battery
backup, and power supplies ensures the optimal up time. The
modular nature of the subsystem and the easy accessibility to all
components ensure the ease of maintenance.
NOTE:
On receiving and unpacking your subsystem, please check the
package contents against the included Unpacking Checklist. If
any modules are missing, please contact your vendor immediately.
Enclosure Chassis
Chassis Overview
The 3U 16 bay / 4U 24 bay RAID storage is housed in a robust
chassis that is divided into the front and the rear sections. Key
components are respectively accessed through the front and rear
panels. The enclosure chassis can be mounted into a standard 19-
inch rack or enclosure cabinet using support brackets that are
separately-purchased.
NOTE:
Components accessed through the front panel are referred to as
“Front Panel Components” and components accessed through
the rear panel are referred to as “Rear Panel Components.”
Front Panel Overview
The front section of the subsystem features a 4x4 / 4x6 layouts for 16
and 24 3.5-inch disk drives, respectively. The handles on the front of
the subsystem enable you to easily extract the chassis from a rack or
cabinet. The front view is shown below. A description of each front
panel component is given below:

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
14
16 Bay Front View
The front panel components include:
•Drive bays with drive tray canisters: The drive bays
accommodate either SAS or SATA-II 3.5” disk drives.
•Forearm handles: The subsystem has right- and left-side
handles for easier rackmount handling.
Hard Drive Numbering
The front section of the 16 bay enclosure houses sixteen (16) hard
drives in a 4x4 configuration. When viewed from the front, the drive
bays (slots) are numbered 1 to 16 from left to right and then from top
to bottom. (The numbering rule applies to the 4U 24bay with 24 slots)
Hard Drive Numbering
Rear Panel Overview
The rear section of the subsystem is accessed through the rear panel
and is reserved for RAID controllers, power supply units (PSUs) and
cooling modules.
A rear view of the subsystem is shown below. Descriptions of each
rear panel component are given in the following sections:

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
15
Figure 1-2: 16 bay (top) and (bottom) Rear View
24 bay Rear View
The enclosure rear section accommodates the following components:
•RAID controller module(s): The RAID controller module
manages all functionalities provided with the subsystem, and
all interface connectors are provided on the controller
faceplates.
•BBU module (within the controller canister): BBU
modules come as standard equipment for the redundant-
controller model, and as an optional module for the single-
controller. The BBU sustains unfinished writes cached in
memory during a power outage in order to prevent data loss.
•PSU modules: The hot-swappable PSUs receive single-
phase power and deliver +5V, +12V, and +3.3V power to the
subsystem. A power switch is located on each PSU to turn
the system on and off.
•Cooling modules: The redundant cooling modules ventilate
the subsystem to maintain a cooling airflow across the
subsystem.
Backplane Board
An internal backplane board separates the front and rear sections of
the enclosure. The backplane consists of traces for logic level signals
and low voltage power paths. It contains no user-serviceable
components.
WARNING!

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
16
When inserting a removable module, DO NOT USE EXCESSIVE
FORCE! Forcing or slamming a module can damage the pins on
the module connectors either on the module itself or on the
backplane. Gently push the module until it reaches the end of
module slot. Feel the contact resistance and use slightly more
pressure to ensure the module connectors are correctly mated. If
the module comes with ejection levers or retention screws, use
them to secure the module.
Subsystem Components
The subsystem houses many active components and most of them
can be accessed through either the front or the rear panel. The
modular design of the components facilitates their easy installation
and removal. Hot-swap mechanisms are incorporated to eliminate
power surges and signal glitches that might occur while removing or
installing these modules.
Drive Trays
Drive Tray Front View
Drive installation and screw locations

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
17
The subsystem comes with 16 or 24 drive trays designed to
accommodate separately purchased, standard 1-inch pitch, 3.5-inch
SAS or SATA-II disk drives. The drive bays are accessible from the
enclosure front panel. Two (2) LEDs on the front bezel indicate the
operating statuses. A rotary bezel lock on each drive tray secures the
hard drive in place, while a release button enables fast retrieval of a
hard drive.
.
WARNING!
Be careful not to warp, twist, or contort the drive tray in any way
(e.g., by dropping it or resting heavy objects on it). The drive tray
has been customized to fit into the drive bays of the subsystem. If
the drive bay superstructure is deformed or altered, the drive trays
may not fit into the drive bays.
MUX Kit
Unlike the dual-ported SAS drives, using the single-port SATA drives
with a redundant-controller RAID requires a MUX board.
Figure 1-3: Dual-ported SAS and Single-port SAS Connectors
The MUX board provides port selector circuits for access from
different RAID controllers to an individual disk drive. See the drawing
below for how it works.

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
18
MUX Kit Working Theory
If SAS drives are preferred, these MUX boards will be unnecessary and
must be manually removed from the drive trays.
MUX Kit
The RAID Controller Module
The default size for the DDR-II DIMM module on RAID controllers is
2GB. RAID controller module contains a main circuit board, a
preinstalled 1GB memory, charger circuitry, and a daughter board
with two additional GbE iSCSI interfaces. The controller module
contains no user-serviceable components. Except when installing/
upgrading the cache memory inside, the controller module should
never be removed or opened.

Galaxy GHDX4 RAID iSCSI-SAS/SATA Installation+Hardware Reference Manual
19
WARNING!
Although the RAID controller can be removed, the only time you
should touch the controller itself is to install the memory modules.
The RAID controller is built of sensitive components and
unnecessary tampering can damage the controller.
The RAID system is managed by the RAID controller(s). The
controller comes with four (4) GbE Ethernet host ports. The
subsystem connects to the host through RJ-45 connectors, while the
connectors are also ready to connect to one or more network
switches, enabling access to your storage volumes in complex
configurations such as data-sharing or Virtual LAN segments.
The docking connector at the rear of the controller board connects
the controller module to the backplane board.
Controller Module Interfaces
All external interfaces that connect to external devices are located on
the controller module’s rear-facing faceplate. The interfaces are listed
below.
Controller Module Interfaces
Host ports: Six (6) Gigabit Ethernet host ports (indicated as
CH0 to CH5 in the diagram shown above) connect the
Galaxy subsystem to the networked iSCSI initiators through
RJ-45 connectors.
Serial port: The controller module comes a serial port for
local access to the firmware embedded configuration utility
and the connection to a UPS device.
LED indicators: Six (6) LED indicators illustrate the system
statuses for system monitoring.
Ejection Levers: Two (2) ejection levers located on the
sides of the controller ensure that the back-end connectors