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EK-BA370-UG-B01

January 1998

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Document:	DIGITAL StorageWorks UltraSCSI RAID Enclosure (DS-BA370-Series) User's Guide
Order Number:	EK-BA370-UG
Revision:	B01
Pages:	186
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DIGITAL StorageWorks
UltraSCSI RAID Enclosure
(DS–BA370–Series)
User's Guide
Part Number: EK–BA370–UG. B01

January 1998
The DIGITAL DS–BA370-series UltraSCSI RAID rack-mountable
enclosure is the basic building block of the UltraSCSI RAID
subsystems. This guide, and the related publications comprise the
basic documentation set for these subsystems.

Digital Equipment Corporation
Maynard, Massachusetts

January 1998
Digital Equipment Corporation makes no representations that the use of its products in the
manner described in this publication will not infringe on existing or future patent rights, nor do
the descriptions contained in this publication imply the granting of licenses to make, use, or sell
equipment or software in accordance with the description.
Possession, use, or copying of the software described in this publication is authorized only
pursuant to a valid written license from DIGITAL or an authorized sublicensor.
© Digital Equipment Corporation 1997, 1998. All rights reserved.

_____________________ Note _____________________
This equipment generates, uses, and may emit radio frequency energy. The
equipment has been type tested and found to comply with the limits for a Class A
digital device pursuant to Part 15 of the FCC rules which are designed to provide
reasonable protection against such radio frequency interference. Operation of this
equipment in a residential area may cause interference in which case the user at
his own expense will be required to take whatever measures may be required to
correct the interference. Any modifications to this equipment – unless expressly
approved by the manufacture – can void the user’s authority to operate this
equipment under part 15 of the FCC rules.

________________________________________________
The following are trademarks of Digital Equipment Corporation: DIGITAL, StorageWorks, and
the DIGITAL logo.

Table of Contents
Preface
Intended Audience ................................................................ xi
Structure ............................................................................... xi
Documentation Conventions ............................................... xiii
Related Documents ............................................................. xiv

Manufacturer’s Declarations
Electromagnetic Compatibility............................................. xv
Acoustic Noise Declarations................................................ xvi

1 Introducing the UltraSCSI RAID Enclosure
An UltraSCSI Bus Overview ...............................................1–4
Product Description.............................................................1–5
Enclosure Status................................................................1–10
Typical Controller Status LEDs................................1–11
Environmental Monitoring Unit (EMU) Status LEDs1–12
Power Verification and Address (PVA) Status LEDs1–12
Power Supply Status LEDs.......................................1–13
SBB Status LEDs .....................................................1–13
I/O Module LEDs.....................................................1–14
Options .............................................................................1–14
Power.......................................................................1–14
Redundant Power Supply Configuration..........1–15
Optimum Power Configuration .......................1–15
Dual Controllers.......................................................1–16
UltraSCSI Bus Expansion ........................................1–16
iii

Table of Contents

2 Operating the UltraSCSI Enclosure
UltraSCSI Configuration Rules ...........................................2–1
General ......................................................................2–2
UltraSCSI RAID Controllers......................................2–3
UltraSCSI Nodes........................................................2–4
UltraSCSI Enclosures.................................................2–5
Enclosure Addressing.................................................2–6
Starting the Subsystem........................................................2–7
Shutting Down the Subsystem.............................................2–9
Using the Power Standby Mode ............................... 2–10
Applying DC Power.................................................2–11
Turning Off the Subsystem ...................................... 2–12
Turning On the Subsystem Power ............................ 2–13
Error Detection, Reporting, Analysis.................................2–14
Enclosure Status................................................................ 2–15
SBB Shelf Status......................................................2–18
SBB Configuration................................................... 2–18
SBB Failure .............................................................2–19

3 Environmental Monitoring Unit (EMU)
Product Description.............................................................3–2
Controller Status ........................................................3–3
I/O Module Status......................................................3–4
Enclosure Configuration Information .........................3–4
EMU Front Panel .......................................................3–5
EMU Communications Connectors ...................3–5
System Fault LED and Alarm Control Switch...3–5
Temperature Fault LED ....................................3–6
Power Supply Status LED.................................3–6
RS232 Connector..............................................3–6
Blower Fault LEDs ...........................................3–7
Configuring the EMU .........................................................3–7
Connecting the EMU Communication Bus..........................3–8
EMU Firmware ...................................................................3–9
Setting the Temperature Sensors ....................................... 3–10
Setting the Blower Speed Control ..................................... 3–13
EMU Status Reporting ...................................................... 3–14
Alarm Control Switch .............................................. 3–15
Subsystem Status LEDs ...........................................3–16
Monitoring Power Supply Operation........................ 3–17
Error Condition Reporting.................................................3–17
iv

Table of Contents

Configuration Fault Code Reporting..................................3–21
Replacing an EMU............................................................3–27

4 Power Verification and Addressing (PVA)
Product Description.............................................................4–2
Functions ............................................................................4–3
PVA Operation....................................................................4–3
EMU Installation Monitoring .....................................4–3
SBB Device IDs.........................................................4–4
Monitoring Power Supply Operation ..........................4–5
Setting the Enclosure Address .............................................4–6
Master Enclosure Address ..........................................4–7
Expansion Enclosure Addresses .................................4–8
Implementing the Standby Power Mode ..............................4–9
Replacing a PVA...............................................................4–11

5 Single-Ended I/O Modules
Replacing I/O Modules and Cables .....................................5–3
Expanding the UltraSCSI Bus .............................................5–3
Controlling the Internal SCSI Bus .......................................5–4
Controlling the External SCSI Bus ......................................5–4
Controlling the Fault Bus ....................................................5–4
Error Reporting ...................................................................5–5
Incompatible I/O Modules..........................................5–5
TERMPOWER Errors ................................................5–6
Rules for Expanding an UltraSCSI Bus ...............................5–7
Cabling an UltraSCSI Subsystem ........................................5–8
Preliminary Procedures ..............................................5–9
Selecting an UltraSCSI VHDCI Cable......................5–10
Shutting Down the Subsystem..................................5–11
Cabling a Three–Enclosure Subsystem.....................5–12
Cabling a Two–Enclosure Subsystem.......................5–16
Replacing an I/O Module ..................................................5–19
Replacing a Cable .............................................................5–21

Table of Contents

6 Power Distribution
Power System Overview .....................................................6–2
Power Configurations.................................................6–2
Standard (n+1) ..................................................6–2
n+4 (Redundant) ...............................................6–3
n+4 (Optimum).................................................6–3
AC Power Source.......................................................6–3
AC Input Power Controller ........................................6–4
Shelf Power Supplies .................................................6–5
AC Power Buses .................................................................6–6
Standard (n+1) Power Configuration...................................6–7
Redundant (n+4) Power Supply Configurations...................6–8
Optimum (n+4) Power Supply Configurations.....................6–9
Power Supply Error Condition Reporting ..........................6–10
Replacing a Power Supply ................................................ 6–11
Power Controller Error Condition Reporting .....................6–13
Replacing a Power Controller ...........................................6–14

7 Storage Devices
Handling an SBB ................................................................7–2
SBB Device Address...........................................................7–3
SBB Status Reporting .........................................................7–3
Identifying a Storage Device...............................................7–5
Guidelines for Replacing SBBs ...........................................7–7
Prerequisites for Replacing an SBB............................7–7
SBB Replacement Methods........................................7–7
Hot Swap ..........................................................7–7
Warm Swap ......................................................7–8
Cold Swap ........................................................7–8
The SBB Connector ...................................................7–9
Replacing an SBB............................................................. 7–10

8 Enclosure Blowers
Function and Operation.......................................................8–3
Error Condition Reporting...................................................8–4
Replacing a Blower.............................................................8–4

Table of Contents

A UltraSCSI Enclosure Specifications
Physical and Electrical Specifications ................................A–2
Operating Environments.....................................................A–3
SBB Thermal Stabilization.................................................A–4

B Assembling an UltraSCSI RAID Subsystem
Installation Sequence ......................................................... B–2
Installing the Power System ............................................... B–3
Installing the EMU............................................................. B–4
Installing the PVA.............................................................. B–4
Installing the Disk Drives................................................... B–4
Installing the I/O Modules.................................................. B–5
Installing Expansion Cables ............................................... B–5
Installing Controller “A” .................................................... B–6
Installing Controller “B” .................................................... B–9
Internal Cables ................................................................. B–10

Glossary

vii

Table of Contents

Figures
Figure 1–1 DS–BA370 Series UltraSCSI Enclosure ...........1–1
Figure 1–2 Typical DS–BA370 Applications .....................1–3
Figure 1–3 Typical Enclosure Bus and Device Addressing.1–6
Figure 1–4 DS–BA370 Status LEDs Locations ................1–10
Figure 1–5 RA7000 Status LEDs Locations .....................1–10
Figure 1–6 Typical Array Controller OCP LEDs..............1–11
Figure 1–7 EMU Status LED Locations ........................... 1–12
Figure 1–8 PVA Status LED Locations ............................ 1–12
Figure 1–9 Power Supply Status LED Locations ..............1–13
Figure 1–10 SBB Status LED Locations...........................1–13
Figure 1–11 I/O Module TERMPOWER LEDs................1–14
Figure 2–1 Power Supply Bezel Label ...............................2–5
Figure 2–2 AC Power Distribution .....................................2–8
Figure 2–3 Enclosure Status LEDs ...................................2–15
Figure 2–4 Pedestal Status LEDs...................................... 2–16
Figure 2–5 Shelf Status LEDs ..........................................2–18
Figure 2–6 SBB Status LEDs ...........................................2–19
Figure 3–1 EMU ................................................................3–1
Figure 3–2 EMU Location .................................................3–2
Figure 3–3 EMU Major Component Locations...................3–5
Figure 3–4 EMU Communication Connections ..................3–8
Figure 3–5 EMU Status LEDs......................................... 3–14
Figure 4–1 PVA ................................................................4–1
Figure 4–2 PVA Location ..................................................4–2
Figure 4–3 PVA Major Components ..................................4–2
Figure 4–4 Master Enclosure Device IDs ...........................4–4
Figure 4–5 Master Enclosure SCSI Bus IDs .......................4–7
Figure 4–6 Enclosure Address 2 SCSI Bus IDs...................4–8
Figure 4–7 Enclosure Address 3 SCSI Bus IDs...................4–9
Figure 5–1 Single-Ended I/O Module.................................5–1
Figure 5–2 I/O Module Location........................................5–2
Figure 5–3 I/O Module Numbering ....................................5–2
Figure 5–4 I/O Module TERMPOWER LEDs....................5–6
Figure 6–1 Enclosure Power System ..................................6–1
Figure 6–2 AC Power Input Controller...............................6–4
Figure 6–3 Shelf Power Supply ..........................................6–5
Figure 6–4 Enclosure AC Power Buses ..............................6–6
Figure 6–5 Standard Power Configuration..........................6–7
Figure 6–6 Redundant Power Configuration.......................6–8
Figure 6–7 Power Supply Status LEDs.............................6–10
Figure 7–1 SBB Handling Rules ........................................7–2
viii

Table of Contents

Figure 7–2 SBB Status LEDs .............................................7–3
Figure 7–3 Typical SBB Regulatory Label........................7–5
Figure 7–4 Typical SBB Bezel Label .................................7–6
Figure 8–1 Enclosure Blower Assemblies Locations ..........8–2

Tables
Table 1–1 UltraSCSI Subsystems Capacities ......................1–7
Table 2–1 DIGITAL–Supported Enclosure Address Settings2–6
Table 2–2 Turning Off the DC Power...............................2–10
Table 2–3 Turning On the DC Power ...............................2–11
Table 2–4 Turning Off the Subsystem Power ...................2–12
Table 2–5 Turning On the Subsystem Power ....................2–13
Table 2–6 Enclosure Status Monitoring............................2–14
Table 2–7 Enclosure Status LED Displays .......................2–17
Table 3–1 EMU Communication Cables ............................3–8
Table 3–2 EMU Set Point Temperature Conversions........3–11
Table 3–3 Temperature Set Point Rules............................3–12
Table 3–4 Subsystem Status LEDs Displays.....................3–16
Table 3–5 DC Voltage Ranges .........................................3–17
Table 3–6 EMU Status Displays........................................3–18
Table 3–7 EMU Fault Code Displays ................................3–22
Table 3–8 Removing an EMU..........................................3–27
Table 3–9 Installing an EMU ..........................................3–27
Table 3–10 EMU Communications Cables.......................3–29
Table 4–1 DC Voltage Ranges ...........................................4–5
Table 4–2 Setting the Enclosure Configuration .................4–6
Table 4–3 DIGITAL Supported Enclosure Addresses.........4–7
Table 4–4 Turning Off the DC Power Distribution ...........4–10
Table 4–5 Turning On the DC Power Distribution............4–10
Table 4–6 Removing a PVA.............................................4–11
Table 4–7 Installing a PVA ..............................................4–12
Table 5–1 TERMPOWER Problems...................................5–6
Table 5–2 UltraSCSI Bus Expansion Rules ........................5–8
Table 5–3 Preliminary Cabling Procedures.........................5–9
Table 5–4 UltraSCSI Bus Cables......................................5–10
Table 5–5 Shutting Down the UltraSCSI Subsystem.........5–11
Table 5–6 Installing Three Enclosure Subsystem Cables ..5–13
Table 5–7 Turning On the UltraSCSI Subsystem..............5–15
Table 5–8 Installing Two Enclosure Subsystem Cables ....5–16
Table 5–9 Removing an I/O Module ................................5–19
ix

Table of Contents

Table 5–10 Installing an I/O Module................................5–20
Table 5–11 Removing an Expansion Cable ......................5–22
Table 5–12 Installing an Expansion Cable........................5–23
Table 6–1 Shelf Power Status LED Displays.................... 6–10
Table 6–2 Removing a Power Supply...............................6–12
Table 6–3 Installing a Shelf Power Supply .......................6–13
Table 6–4 Removing an AC Input Power Controller ........6–15
Table 6–5 Installing an AC Power Controller................... 6–16
Table 7–1 SBB Status LED Displays .................................7–4
Table 7–2 Removing an SBB ........................................... 7–10
Table 7–3 Installing an SBB ............................................ 7–11
Table 8–1 Removing a Blower...........................................8–5
Table 8–2 Installing a Blower Assembly ............................8–6

Preface
The DIGITAL StorageWorks UltraSCSI RAID Enclosure
(DS–BA370-Series) User’s Guide describes the functions, operations,
components, configurations, assembly, and specifications of this enclosure.

Intended Audience
This document is for use by personnel responsible for designing,
configuring, assembling, installing, and operating UltraSCSI RAID
subsystems using a DS–BA370-series enclosure mounted in either a data
center cabinet or a departmental server cabinet.

Structure
The organization of this manual is as follows:
Chapter 1
This chapter describes the UltraSCSI RAID enclosure functions, uses,
components, and features.
Chapter 2
This chapter describes how to configure and operate an UltraSCSI RAID
enclosure.
Chapter 3
This chapter describes the environmental monitoring unit (EMU) operation,
functions, uses, configuration, and replacement procedures.
Chapter 4
This chapter describes the power verification and addressing (PVA)
assembly operation, functions, uses, configuration, and replacement
procedures.

Preface

Chapter 5
This chapter describes the single-ended I/O module operation, functions,
uses, configuration, and replacement procedures.
Chapter 6
This chapter describes the enclosure power distribution components
operation, functions, uses, configuration, and replacement procedures.
Chapter 7
This chapter describes the disk drives operation, functions, uses,
configuration, and replacement procedures.
Chapter 8
This chapter describes blower operation, status reporting, and replacement
procedures.
Appendix A
This appendix describes the enclosure physical, electrical, and
environmental specifications.
Appendix B
This appendix describes the procedures for installing components in an
enclosure to create an UltraSCSI RAID subsystem.
Glossary

xii

Preface

Documentation Conventions
The documentation conventions used in this publication are as follows:
boldface
type

Boldface type indicates the first instance of terms being
defined in the text, the glossary, or both.

italic type

Italic type indicates emphasis and publication titles.
Italic type in the glossary indicates a cross–reference.

A/R

As required
LED is OFF
LED is ON or blinking slowly
LED is FLASHING (blinking rapidly)
Warning

Information essential to people’s safety

Caution

Information the user needs to know to avoid damaging
the software or hardware.

Note

Information that might be of special importance to the
user.
Single-ended SCSI bus

Differential SCSI bus

xiii

Preface

Related Documents
The following publications contain additional information about the
UltraSCSI RAID subsystem.
Publication Title

Order Number

AC Input Power Controller (DS–BA35X–HE) Installation Guide

EK–35XHE–IG

Blower (DS–BA35X–MK) Installation Guide

EK–35XMK–IG

Environmental Monitoring Unit (DS–BA35X–EB) Installation Guide

EK–35XEB–IG

HSZ70 Array Controller HSOF Version 7.0 CLI Reference Manual

EK–CLI70–RM

HSZ70 Array Controller HSOF Version 7.0 Configuration Manual

EK–HSZ70–CG

HSZ70 Array Controller HSOF Version 7.0 Service Manual

EK–HSZ70–SV

Installing a Host Bus Cable Ferrite Bead

EK–SWXES–IG

Installing an HSZ70 ECB Cable

EK–HSZ70–TE

Operating System Specific Release Notes

See system specific
“Getting Started”
manual

Power Verification and Addressing Assembly (DS–BA35X–EC)
Installation Guide

EK–35XEC–IG

Shelf Power Supply (DS–BA35X–HH) Installation Guide

EK–35XHH–IG

Single-Ended I/O Module (DS–BA35X–MN) Installation Guide

EK–35XMN–IG

UltraSCSI RAID Data Center Cabinet (DS–SW600-Series)
Installation and User’s Guide

EK–SW600–UG

UltraSCSI Subsystem Standby Power Operation

EK–POWER–IG

xiv

Manufacturer’s Declarations
Electromagnetic Compatibility
You can install this CE–Mark Class A certified product in a commercial or
an office environment.
__________________ WARNING! ___________________
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.
________________________________________________
__________________ ACHTUNG! ___________________
Dieses ist ein Gerät der Funkstörgrenzwertklasse A. In
Wohnbereichen können bei Betrieb dieses Gerätes
Rundfunkstörungen auftreten, in welchen Fällen der
Benutzer für entsprechende Gegenmaßnahmen
verantwortlich ist.
________________________________________________
_______________ AVERTISSEMENT! ________________
Ceci est un produit de Classe A. Dans un environnement
domestique, ce produit risque de créer des interférenences
radioélectriques, il appartiendra alors à l’utilisateur de
prendre les mesures spécifiques appropriées.
________________________________________________

Manufacturer’s Declarations

Acoustic Noise Declarations
DIGITAL declares that the acoustic values of this product are as follows:
Acoustics – Declared Values per ISO 9296 and ISO 7779:
Sound Power Level
LWAd, B
Product

Sound Pressure Level
LpAm dBA
(bystander positions)

Idle

Operate

Idle

Operate

RAID Array 7000 Subsystem
(DS–SWXRE–HA) with:
2 – ac power controllers
(DS–BA35X–HE)
8 – 180 W shelf power supplies
(BA35X–HH)
24 – disk drives (2, 4, 9 GB)

6.1

N/A

48.4

RAID Array 7000 Subsystem
(DS–SWXRE–HA) with:
2 – ac power controllers
(DS–BA35X–HE)
8 – 180 W shelf power supplies
(BA35X–HH)
24 – disk drives (2, 4, 9 GB)

6.1

6.3

48.4

______________________________ Note _____________________________
Current values for sound power levels are available from DIGITAL representatives.
1 Bel = 10 dBA.
_________________________________________________________________

xvi

Manufacturer’s Declarations

Schallemissionswerte – Werteangaben nach ISO 9296 und ISO 7779/DIN EN27779:
Schalleistungspegel
LWAd, B

Schalldruckpegel
LpAm, dBA
(Zuschauerpositionen)

Leerlauf

Betrieb

Leerlauf

Betrieb

RAID Array 7000 Subsystem
(DS–SWXRE–HA) with:
2 – ac power controllers
(DS–BA35X–HE)
8 – 180 W shelf power supplies
(BA35X–HH)
24 – disk drives (2, 4, 9 GB)

6,1

N/A

48,4

RAID Array 7000 Subsystem
(DS–SWXRE–HA) with:
2 – ac power controllers
(DS–BA35X–HE)
8 – 180 W shelf power supplies
(BA35X–HH)
24 – disk drives (2, 4, 9 GB)

6,1

6,3

48,4

Gerät

______________________________ Note ______________________________
Aktuelle Werter für spezielle Austüstungsstufen sind über die Digital Equipment
Vertretungen erhältlich. 1 Bel = 10 dBA.
__________________________________________________________________

xvii

SES Template Word 7 Blank Page Fix by Peter LaQuerre

1
Introducing the UltraSCSI
RAID Enclosure
The StorageWorks™ UltraSCSI (small computer system interface) RAID
(random array of independent disks) enclosure (DS–BA370-series), see
Figure 1–1, is the basic building block for DIGITAL™ single-ended
UltraSCSI RAID subsystems.
Figure 1–1 DS–BA370 Series UltraSCSI Enclosure

CXO5797A

™

Trademark of Digital Equipment Corporation
Ultra SCSI RAID Enclosure 1–1

Introducing the Ultra SCSI RAID Enclosure

This enclosure cannot function until:
•

It is installed in an UltraSCSI data center cabinet (DS–SW600-series)

•

It is installed in an UltraSCSI departmental server (DS–
SWXRE-series).

•

3.5-inch StorageWorks building block (SBB) disk drives are installed

•

A compatible array controller is installed and connected to a host
computer or adapter

•

The enclosure and the subsystem are configured for UltraSCSI
operation
______________________Note _____________________
The “DS–” model number prefix defines new DIGITAL storage
products. In some cases, these numbers may be similar to an
existing product number. For example, the DS–BA35X–HE ac
power controller and the BA35X–HE ac power controller have
similar model numbers but are not interchangeable. These
products are not interchangeable. Installing incompatible
products in a StorageWorks subsystem could result in degraded
operation or non-compliance with country-specific
certifications.
________________________________________________

See Figure 1–2 for the DIGITAL-supported enclosure applications.

1–2 UltraSCSI RAID Enclosure

Introducing the UltraSCSI RAID Enclosure

Figure 1–2 Typical DS–BA370 Applications

1
0

0
0

1
0

0
0

1
0

1
0
0

1
0

CXO6264A

Ultra SCSI RAID Enclosure 1–3

Introducing the Ultra SCSI RAID Enclosure

An UltraSCSI Bus Overview
Developed by the Digital Equipment Corporation and subsequently
standardized by the ANSI (American National Standards Institute) SCSI
committee as standard X3T10, UltraSCSI is a technology that incorporates
several improvements over a Fast SCSI 10 bus.
UltraSCSI increases the maximum transfer rate on a wide (16-bit) SCSI bus
from 10 MHz (mega Hertz) to 20 MHz. This results in an increase in
maximum bus bandwidth from 20 MB/sec (mega bytes per second) to
40 MB/sec.
UltraSCSI incorporates smaller very high density computer interconnect
(VHDCI) cables and connectors. The connector is up to half the size of the
Fast SCSI HD68 (high-density 68-pin) connector and the cables are thinner.
The higher speed of the single-ended UltraSCSI signals can cause
degradation of signal integrity over the same distances as single-ended Fast
SCSI signals. However, the UltraSCSI bus can run over much greater
distances than Fast SCSI in either single-ended or differential mode. To
attain these greater distances, UltraSCSI defines, and the StorageWorks
UltraSCSI implements the bus segment concept.
An UltraSCSI bus segment is as an unbroken electrical path consisting of
conductors (in cables or on backplanes) and connectors. Every UltraSCSI
bus segment must have two terminators, one at each end of the bus
segment. Bus segments can either be single-ended or differential, depending
on the type of terminators used in that segment. In other words, an
UltraSCSI bus segment corresponds to what in Fast SCSI was an entire
SCSI bus. As in Fast SCSI, a bus segment can only support devices of the
same type as its terminators. You cannot, for example.
Use a differential SCSI device on a single-ended bus segment.
______________________Note _____________________
The DIGITAL UltraSCSI RAID enclosure only supports the
single-ended UltraSCSI bus.
________________________________________________

1–4 UltraSCSI RAID Enclosure

Introducing the UltraSCSI RAID Enclosure

Product Description
The UltraSCSI enclosure is a rack mountable unit that accommodates the
following components:
•

A minimum of one, or a maximum of two, UltraSCSI controllers with
cache modules1, such as the DS–HSZ70-series

•

An environmental monitoring unit (DS–BA35X–EB), the EMU, that
monitors enclosure operation, detects and reports error conditions, and
can automatically initiate corrective actions

•

A power verification and addressing assembly (DS–BA35X–EC), the
PVA, that establishes enclosure and storage device addressing,
monitors enclosure operation, and detects and reports error conditions.

•

A minimum of one, or a maximum of two, ac power controllers (DS–
BA35X–HE), the power controllers, to distribute ac power to the
shelf power supplies

•

A minimum of five, and a maximum of eight shelf power supplies (DS–
BA35X–HH)

•

Eight dual-speed blowers (DS–BA35X–ML) that cool the components
by drawing air in through the front and exhausting it out the rear

•

Six single-ended I/O modules (DS–BA35X–MN) for connecting
enclosures together

•

A maximum of 24 single-ended, 3.5-inch SBB disk drives

•

Expansion enclosures have filler panels installed in the controller and
cache module slots that improve air flow and reduce EMI radiation

•

For enclosures with fewer than 24 disk devices, installing the optional
blank bezels (DS–BA35X–PB) improve air flow and reduce EMI
radiation.

•

The blank panels in the controller B and cache module B locations
improve air flow and control EMI in enclosures with only one
controller.

Each cache module requires an external cache battery (DS–BA35X–Bx series).
The batteries are installed either in a data center cabinet shelf or a
departmental server cabinet top cover—not in the enclosure.
Ultra SCSI RAID Enclosure 1–5

Introducing the Ultra SCSI RAID Enclosure

The enclosure backplane eliminates the need for cables to connect the six
vertical buses to the four horizontal SBB shelves. All the devices on a shelf
use the same SCSI bus ID. The PVA selectable enclosure UltraSCSI ID
defines the SCSI bus ID of each shelf. See Figure 1–3 for bus and shelf
identifiers when viewing the enclosure from the front.
Figure 1–3 Typical Enclosure Bus and Device Addressing
SCSI bus
1

Shelf 4

Shelf 3

Shelf 2

Shelf 1

CXO6266A

The ac power controllers distribute ac power to the individual shelf power
supplies through ac power cables. The backplane distributes the dc output
voltages (+5 V dc and +12 V dc) over two buses to the:
•

EMU

•

PVA

•

UltraSCSI bus controllers and cache modules

•

Disk drives

1–6 UltraSCSI RAID Enclosure

Introducing the UltraSCSI RAID Enclosure

•

I/O modules

UltraSCSI RAID Subsystem
A subsystem is one or more departmental server cabinets or data center
cabinets with enclosures. Each subsystem requires a master enclosure with
an UltraSCSI controller installed. Installing one or two expansion
enclosures and connecting them with cables creates an expanded subsystem.
See Table 1–1 for the capacities of the various subsystems:
_____________________ Note ______________________
Not all array controllers support configurations with expansion
cabinets. Refer to the array controller documentation to verify
that your controller can support multiple cabinets.
________________________________________________
Table 1–1 UltraSCSI Subsystems Capacities
Enclosures

SCSI Buses

Disk Drives

Total Disk Drives

EMU
The device that monitors the status of the UltraSCSI RAID enclosure to
include power, ambient (intake) air temperature, blower status, and so forth.
It also detects error and fault conditions, displays these conditions, reports
the conditions to the user and the array controller, and, in some cases,
implements corrective actions.
PVA
The UltraSCSI RAID enclosure assembly whose primary functions are as
follows:
•

Allows the user to select the enclosure UltraSCSI bus ID,

•

Enables the user to place the subsystem in a standby power mode
condition or return it to an operational status,

Ultra SCSI RAID Enclosure 1–7

Introducing the Ultra SCSI RAID Enclosure

•

In conjunction with the associated EMU, ensures that the major
components are functioning properly and notifies the user and the array
controller of error or fault conditions. Each PVA functions only with its
host enclosure and EMU. There is no master PVA in the UltraSCSI
RAID subsystem.

Master Enclosure
Each UltraSCSI RAID subsystem, whether it has one, two, or three
enclosures, is under the control of the master enclosure. The enclosure
with the array controllers is the master enclosure. The EMU in these
enclosures is the only EMU that can communicate directly with the array
controllers. In a multiple enclosure, or expansion configuration, this
enclosure also communicates with the other enclosures using the EMU—
EMU communications bus. The master enclosure PVA SCSI bus address
setting is always 0. Using address 0 automatically assigns SCSI bus device
addresses 0, 1, 2, and 3 to the four disk drive shelves.
Master EMU
The environmental monitoring unit in the master enclosure is the Master
EMU. This is the only EMU that communicates directly with the array
controller and the expansion enclosure EMUs over the EMU—EMU
communications bus. This EMU controls the operation of the entire
subsystem to include error detection, reporting, and status displays.
Expansion Enclosure
An UltraSCSI RAID enclosure connected to the master enclosure with
cables is an expansion enclosure. Depending upon the array controller, a
subsystem can have a maximum of two expansion enclosures. The
expansion PVA SCSI bus address setting is either:
2–to establish SCSI bus device addresses 8, 9, 10, and 11.
3– to establish SCSI bus device addresses 12, 13, 14, and 15.
____________________ Caution ____________________
Not all array controllers support an UltraSCSI RAID subsystem
with more than one enclosure. Read the array controller
documentation to ensure the controller supports expanded
configurations.
________________________________________________

1–8 UltraSCSI RAID Enclosure

Introducing the UltraSCSI RAID Enclosure

Expansion EMU
An environmental monitoring unit installed in an expansion enclosure is an
Expansion EMU. This EMU communicates with the master EMU over the
EMU—EMU communications bus. Upon loss of communications with the
master EMU, the expansion EMU assumes control of certain expansion
enclosure functions. In this state, the expansion EMU cannot communicate
with the UltraSCSI controller
I/O Module
This device provides termination for the internal UltraSCSI buses and is the
connection point for the cables connecting the six buses to an expansion
enclosure.
SCSI Bus Controllers
A hardware–software device that manages SCSI bus communications to
devices. Controllers typically differ by the type of interface to the host and
provide functions beyond those the devices support. Other terms commonly
used include array controller or controller..
Cache Module
A storage buffer required for each bus controller.
ECBs
ECBs (external cache batteries) provide backup power to the cache module
to protect data integrity if there is a power failure.

Ultra SCSI RAID Enclosure 1–9

Introducing the Ultra SCSI RAID Enclosure

Enclosure Status
When any of the multiple error detection circuits determines there is a
problem, an audible alarm may sound and one or more sets of status LEDs
(light emitting diodes) display an error code.
The enclosure has two go—no go indicators (see Figure 1–4). The green
LED is the System OK LED; the amber LED is the Fault LED. When the
Fault LED is on, you must check the other status LEDs to determine the
cause of the error.
•

For an enclosure in a pedestal these LEDs are part of the pedestal. (See
Figure 1–5.)

•

For an enclosure in a DS–SW600 series cabinet, LEDs on the cabinet
door also displays the enclosure status.

Figure 1–4 DS–BA370 Status LEDs
Locations

Figure 1–5 RA7000 Status LEDs
Locations

System OK
(green)
Fault
(amber)

System OK
(Green)

Fault
(Amber)

1
0

CXO5451B

CXO5751A

1–10 UltraSCSI RAID Enclosure

Introducing the UltraSCSI RAID Enclosure

Typical Controller Status LEDs
The operator control panel (OCP) status LEDs (see Figure 1–6) display the
controller status. For a detailed explanation of each status code refer to the
controller documentation.
Figure 1–6 Typical Array Controller OCP LEDs
Port
button
(6X)

Reset
button

Port/Fault
LEDS
(6X)

Host port
power fault
LED
CXO5732A

The green array controller LED in the RESET button indicates controller
status. This LED flashes constantly once the controller initialization is
complete and the software is functioning. Pressing this switch resets the
controller.
The amber port LEDs are off when the bus is functioning properly. A port
LED that is on or flashing indicates that a device on that bus is not
functioning properly.

Ultra SCSI RAID Enclosure 1–11

Introducing the Ultra SCSI RAID Enclosure

Environmental Monitoring Unit (EMU) Status LEDs
The EMU status LEDs (see Figure 1–7) have multiple functions (see
Chapter 3, “Environmental Monitoring Unit”).
Figure 1–7 EMU Status LED Locations
1

CXO5774A

2.
3.
4.

System fault LED (amber).
Temperature fault LED (amber).
Power status LED (green).

Blower fault, Error Condition, and Fault Code LEDs (amber).

Power Verification and Address (PVA) Status LEDs
The PVA (Figure 1–8) has only one status LED, the power status LED. For
a detailed description of the PVA status displays and alarm see Chapter 4,
“Power Verification and Addressing (PVA).”
Figure 1–8 PVA Status LED Locations
1

CXO5821A

The green power status LED is part of the standby power switch.

1–12 UltraSCSI RAID Enclosure

Introducing the UltraSCSI RAID Enclosure

Power Supply Status LEDs
Each power supply (see Figure 1–9) has two green status LEDs—the Shelf
Status LED and the Power Supply Status LED. See Chapter 6, “Power
Distribution” for detailed information about these LEDs.
Figure 1–9 Power Supply Status LED Locations

Shelf
status LED
(Green)
Power supply
status LED
(Green)

CXO-4787A-MC

SBB Status LEDs
Each SBB (see Figure 1–10) has two status LEDs—a green device activity
LED and an amber device fault LED. See Chapter 7, “Storage Devices” for
detailed information about these LEDs.
Figure 1–10 SBB Status LED Locations

Device
activity
(Green)
Device
fault
(Amber)

CXO-4652A-MC

Ultra SCSI RAID Enclosure 1–13

Introducing the Ultra SCSI RAID Enclosure

I/O Module LEDs
Each I/O module (see Figure 1–11) has two green status LEDs that display
the status of both the internal and the external SCSI bus terminator power
(TERMPOWER). Whenever TERMPOWER is present, the LED is ON.
See Chapter 5, "Single–Ended I/O Modules," for detailed information about
these LEDs.
Figure 1–11 I/O Module TERMPOWER LEDs

External
TERMPOWER

Internal
TERMPOWER
CXO5829A

Options
The following sections describe the UltraSCSI RAID subsystem user
selectable options:

Power
The standard UltraSCSI enclosure power configuration consists of one ac
power controller and five shelf power supplies. This configuration provides
the minimum SBB power supply redundancy. A system power failure will
occur for any of the following conditions:
•

Loss of the ac power source

•

Failure of the ac power controller

•

Failure of two shelf power supplies

The user has the option of modifying the power configuration to eliminate
single points of failure,

1–14 UltraSCSI RAID Enclosure

Introducing the UltraSCSI RAID Enclosure

Redundant Power Supply Configuration
Adding three SBB shelf power supplies and a second ac power controller
provides significantly more power redundancy than the standard
configuration. A system power failure will occur for any of the following
conditions:
•

Loss of the ac power source

•

Failure of both ac power controllers

•

Failure of five shelf power supplies

DIGITAL suggests using this configuration to provide additional power
supply redundancy.
Optimum Power Configuration
Adding three power supplies, a second ac power controller, and a second ac
power source provides the optimum power redundancy. With separate ac
power sources for each ac power controller there are no single points of
failure.
_____________________ Note ______________________
For optimum operation each ac power controller should use a
different ac power source.
________________________________________________
A system power failure will occur for any of the following conditions:
•

Loss of both ac power sources

•

Failure of both ac power controllers

•

Failure of five shelf power supplies

•

Failure of the power source for power B and 1 power supply on bus A

•

Failure of the power controller on bus A and 1 power supply on bus B

•

Failure of the power controller on bus B and 1 power supply on bus A

•

Failure of the power controller on bus A and 1 power supply on bus B

DIGITAL recommends using this configuration to eliminate all single
points of power failure.

Ultra SCSI RAID Enclosure 1–15

Introducing the Ultra SCSI RAID Enclosure

Dual Controllers
Establishing a dual-redundant subsystem with two UltraSCSI controllers,
two cache modules, and external cache batteries, is the most effective and
efficient method of ensuring continuous subsystem operation.

UltraSCSI Bus Expansion
Some controllers support expanding the UltraSCSI bus from the master
enclosure to two expansion enclosures.

1–16 UltraSCSI RAID Enclosure

2
Operating the UltraSCSI
Enclosure
Setting up an UltraSCSI RAID subsystem for operation involves
implementing the procedures described in the system specific “Getting
Started” manual provided with each system. This chapter supplements and
expands on this information.
Other chapters in this manual contain detailed information about individual
component functions, operations, error conditions, and so forth.

UltraSCSI Configuration Rules
Proper operation of the subsystem requires complying with both the
UltraSCSI and hardware configuration rules. In some instances operating
system specific configuration rules also apply.

Ultra SCSI RAID Enclosure 2–1

Operating the UltraSCSI Enclosure

General
The following rules apply to the UltraSCSI bus:
1.

The UltraSCSI RAID subsystems can transfer data at a higher rate
(40 MB/sec versus 20 MB/sec) than do the FAST 10 subsystems.

UltraSCSI subsystems require 68-pin VHDCI cables and connectors.
The physical difference in the contact spacing precludes using FAST 10
cables.

The following devices use a SCSI bus address and are SCSI bus
“nodes:”
•

Adapters

•

Controllers

•

Storage devices

Every node on a bus must have a unique SCSI ID.

The SCSI ID for controller “A” is always 7.

The SCSI ID for controller “B” is always 6.

There are slots for six 3.5-inch SBB nodes in a shelf. The address
switch on the PVA module determines node SCSI bus IDs. There is a
maximum of 12 valid DS–BA370 SCSI IDs—0 through 3 and
8 through 15.

A DS–BA370 UltraSCSI bus cannot support 5.25-inch devices.

With only UltraSCSI devices installed the maximum transfer rate of an
UltraSCSI bus is 40 MB/sec.

10. Installing a FAST 10 storage device limits the bus segment operations
as follows:

2–2 Ultra SCSI RAID Enclosure

Operating the UltraSCSI Enclosure

The maximum transfer rate when using a wide (–VW suffix),
FAST 10 device is 20 MB/sec.

The maximum transfer rate when using a narrow (–VA suffix),
FAST 10 device is 10 MB/sec.

UltraSCSI RAID Controllers
___________________ Caution _____________________
Should there be a conflict in controller configuration
information between this document and the controller specific
documentation, use the information in the controller specific
documentation.
________________________________________________
The following general configuration rules apply to the UltraSCSI RAID
array controllers:
1.

The controller “A” SCSI bus ID is always 7.

The controller “B” SCSI bus ID is always 6.

Some controllers support FAST 10 (10 MB/sec) 16–bit (wide) disk
drives.

Some controllers support FAST 20 (20 MB/sec) 16–bit (wide) disk
drives.
_____________________ Note ______________________
Disk drive support is controller specific. Refer to your array
controller documentation to determine compatible disk drives.
________________________________________________

UltraSCSI RAID Enclosure 2–3

Operating the UltraSCSI Enclosure

UltraSCSI Nodes
A node is a SCSI device that uses a SCSI bus ID. The following rules apply
to UltraSCSI nodes, such as disks, tapes, and so forth.
1.

Only a controller node can use SCSI bus ID 7.

Only a controller node can use SCSI bus ID 6.

No node can use SCSI bus IDs 4, 5, 13, 14, or 15

An UltraSCSI bus cannot support 5.25-inch devices.

The maximum bus transfer rates are device dependent.

A bus with all UltraSCSI devices has a maximum transfer rate of
40 MB/sec.

A bus with one wide (16-bit), FAST 10, SCSI devices (–VW
suffix) installed, has a maximum transfer rate of 20 MB/sec.

A bus with one narrow (8-bit), FAST 10, SCSI devices (–VA
suffix) has a maximum transfer rate of 10 MB/sec.

The valid device SCSI bus IDs are device type dependent.
a.

An UltraSCSI device can use device addresses 0 through 6 or
8 through 14.

A wide (16-bit), FAST 10, SCSI devices (–VW suffix) can use
device addresses 0 through 6 or 8 through 14.

A narrow(8-bit), FAST 10, SCSI devices (–VA suffix) can use
device addresses 0 through 6.

2–4 Ultra SCSI RAID Enclosure

Operating the UltraSCSI Enclosure

UltraSCSI Enclosures
The following configuration rules apply to the UltraSCSI RAID subsystem
enclosures:
1.

The only compatible power controller is the model DS–BA35X–HE.

The only compatible power supply is the model DS–BA35X–HH
(180 W). The bezel label (see Figure 2–1) identifies these power
supplies.

Figure 2–1 Power Supply Bezel Label

CXO5926A

UltraSCSI RAID Enclosure 2–5

Operating the UltraSCSI Enclosure

Enclosure Addressing
The following configuration rules apply to the UltraSCSI RAID enclosure
address settings when there is a controller in the master enclosure:
1.

The enclosure containing the array controller is the master enclosure.
The PVA SCSI ID switch setting for the master enclosure is always 0.

UltraSCSI subsystem expansion enclosures use either PVA SCSI ID
switch setting 2 or 3.
•

The PVA SCSI ID switch setting for the first expansion enclosure
is always 2.

•

The PVA SCSI ID switch setting for the second expansion
enclosure is always 3.

See Table 2–1 for the DIGITAL-supported enclosure address settings.
Table 2–1 DIGITAL–Supported Enclosure Address Settings
No. of Enclosures

Master

Expansion 1

Expansion 2

None

2–6 Ultra SCSI RAID Enclosure

Operating the UltraSCSI Enclosure

Starting the Subsystem
After installing the departmental server cabinet or data center cabinet and
connecting the enclosures, you can apply power to start the subsystem.
Applying power to all the enclosures causes the EMU, PVA, and array
controller to automatically begin system operation.
_____________________ Note ______________________
Before applying power to the subsystem, be sure to configure
the entire subsystem, to include the host and the array
controller, as described in the appropriate publications.
________________________________________________
Initial power application is simply a matter turning on the ac power
controllers located in the lower left and right corners of the enclosure (see
Figure 2–2). Pressing 1 on the ac power switch applies ac power only to the
shelf power supplies on the associated power bus (bus A or B). Apply power
in the following sequence:
1.

All expansion enclosures.

Master enclosure.

UltraSCSI RAID Enclosure 2–7

Operating the UltraSCSI Enclosure

Figure 2–2 AC Power Distribution
AC Input Power Controller

AC Input Power Controller and SBB Shelf
Power Supply Locations
Power
bus A

Power
bus B

1
0

CXO5113A

4A 19 20 21 22 23 24 4B

Shelf 4

3A 13 14 15 16 17 18 3B

Shelf 3

10 11 12 2B

Shelf 2

Shelf 1

PVA
EMU
Controller A
Controller B
Cache A
Cache B

CXO5808A

2–8 Ultra SCSI RAID Enclosure

Operating the UltraSCSI Enclosure

Shutting Down the Subsystem
Shutting down the subsystem involves (1) Clearing the cache module and
shutting down the controller. (2) Either turning OFF the dc power in an
enclosure (the standby power mode) or turning OFF the ac power controllers
(full power shutdown).
Placing the subsystem in the standby power mode disconnects the dc power
from the backplane. The ac power is still applied to the shelf power
supplies. In this mode the EMU alarm control switch now functions as a
standby power switch. To restore the dc power to the backplane requires
pressing the standby power switch on each EMU.
___________________ Caution _____________________
Failure to clear the cache module and shut down the array
controller before removing power will disrupt data transfers.
Therefore, always shut down the array controller as described in
the array controller documentation.
________________________________________________
Turning the subsystem off involves shutting down the array controller and
then turning off the ac power controllers in each enclosure.
Powering down an enclosure always involves shutting down the array
controller and then pressing the PVA standby power switch on an expansion
enclosure.
When there are no expansion enclosures, shut down the array controller and
then press the PVA standby power switch on the master enclosure.

UltraSCSI RAID Enclosure 2–9

Operating the UltraSCSI Enclosure

Using the Power Standby Mode
Complete the procedure in Table 2–2 to place the subsystem in standby
power mode (that is, turning off the dc power distribution)
Table 2–2 Turning Off the DC Power
1.

Clear the cache module and shut down the array controller (see the
array controller documentation).

Shut down the array controller, press and hold the PVA standby
power switch (CALLOUT 1) on an expansion enclosure until the
master EMU initiates a power shut down on all enclosures.
If there is no expansion enclosure, press and hold the PVA standby
power switch (CALLOUT 1) on the master enclosure until the EMU
initiates a power shut down on all enclosures.
1

CXO5821A

The EMU alarm control switch (CALLOUT 2) on each enclosure now
functions as the dc power switch.
1

CXO5774A

2–10 Ultra SCSI RAID Enclosure

Operating the UltraSCSI Enclosure

Applying DC Power
Complete the procedure in Table 2–3 to restore the dc power within each
enclosure.
Table 2–3 Turning On the DC Power
1.

When there are no expansion enclosures, go to Step 3.

Momentarily press the EMU alarm control switch (CALLOUT 2) on
each expansion enclosure.
1

CXO5774A

Momentarily press the EMU Alarm control switch (CALLOUT 2) on
the master enclosure.

The array controller restores the subsystem to an operational state.

UltraSCSI RAID Enclosure 2–11

Operating the UltraSCSI Enclosure

Turning Off the Subsystem
Adding enclosures or moving the subsystem may require removing all
power from the subsystem. Complete the procedure in Table 2–4 to remove
all power.
Table 2–4 Turning Off the Subsystem Power
1.

Shut down the array controller, press and hold the PVA standby
power switch (CALLOUT 1) on an expansion enclosure until the
master EMU initiates a power shut down on all enclosures.
When there is no expansion enclosure, press and hold the PVA
standby power switch (CALLOUT 1) on the master enclosure until the
master EMU initiates a power shut down on all enclosures.
1

CXO5821A

Turn OFF all the power controllers by pressing O on each power
switch.

AC power
switch

AC receptacle

CXO5488A

______________________Note _____________________
When there is no expansion EMU, press the PVA standby power
switch on the master enclosure.
________________________________________________
2–12 Ultra SCSI RAID Enclosure

Operating the UltraSCSI Enclosure

Turning On the Subsystem Power
After completing subsystem expansion or moving the subsystem, complete
the procedure in Table 2–5:
Table 2–5 Turning On the Subsystem Power
1.

When there are no expansion enclosures, go to Step 4.

Starting with an expansion enclosure, turn ON all the power
controllers by pressing 1 on each power switch.

AC power
switch

AC receptacle

CXO5488A

Repeat Step 1 for the other expansion enclosure.

Turn on all the ac power controllers in the master enclosure.

The array controller restores the subsystem to an operational state.

UltraSCSI RAID Enclosure 2–13

Operating the UltraSCSI Enclosure

Error Detection, Reporting, Analysis
The EMU and PVA constantly monitor the operational status of the
enclosure and its components. In some instances, automatic corrective
action implementation occurs. Status changes can be reported to the user
using a combination of LEDs, the EMU audible alarm, and an optional
maintenance terminal connected to the array controller. Table 2–6 lists the
major enclosure components and the status monitored.
Table 2–6 Enclosure Status Monitoring
Component

Status Monitored

•

Intake air temperature

•

Exhaust temperature

•

AC input power.

•

Number of operational 180 W power supplies.

•

Enclosure address

•

Output of dc power supplies

•

DC bus voltages

•

Termination I/O module dc voltage

•

Control signal response

•

Controller detected fault condition.

•

Removal

•

Installation

•

Operation

•

Operating speed

•

Installation

EMU

•

Installation

PVA

•

Installation

Enclosure

Power

Storage
devices
(SBBs)

Blowers

For a detailed description of status LEDs, and specific error conditions, see
the chapter for each component.

2–14 Ultra SCSI RAID Enclosure

Operating the UltraSCSI Enclosure

Enclosure Status
_____________________ Note ______________________
HSZ70-series controllers can process the enclosure status
signals. Other adapters and controllers may not have this
capability.
________________________________________________
The primary elements of the enclosure status are the enclosure power and
the blowers. Loss of either a dc voltage or a blower is an error condition.
The enclosure notifies the user of the problem by sounding an audible alarm
and changing the status LED displays (see Table 2–7). When the enclosure
is mounted in a data center cabinet or a departmental server cabinet, the two
status LEDs may be connected to LEDs on the front door.
Figure 2–3 Enclosure Status LEDs
System OK
(green)
Fault
(amber)

CXO5751A

UltraSCSI RAID Enclosure 2–15

Operating the UltraSCSI Enclosure

The status LEDs (see Figure 2–4) are in the upper right corner of the
pedestal.
Figure 2–4 Pedestal Status LEDs

System OK
(Green)

Fault
(Amber)

1
0

CXO5451B

The green LED is the System OK LED and the amber LED is the system
fault LED.
The green LED indicates the enclosure is operational. This LED can be ON
as long as at a minimum number of redundant components, such as blowers,
or power supplies, are functioning correctly.
When the amber system fault LED is ON, it indicates one or more
components have an error or fault condition. To isolate an error condition
requires you to observe LEDs on the EMU, PVA, power supplies, SBBs,
and array controllers (see Table 2–7.

2–16 Ultra SCSI RAID Enclosure

Operating the UltraSCSI Enclosure

Table 2–7 Enclosure Status LED Displays
When the LED display is

LED is ON
LED is OFF

Data
Center
Cabinet

The enclosure status is…

Dept.
Server
Cabinet

The enclosure is operating normally. There
are no detected errors.
There are one or more failed components.
1. Observe the EMU front panel to see if
there is an overtemperature condition, a
blower problem, or a power problem.
Replace the defective blower or power
components.
2. Observe individual SBBs for error
condition.
3. Check the array controller optional
system maintenance terminal for error
messages.
Either there is no power applied to the
enclosure or the enclosure is in a reset state.
1. Ensure that ac power is present at the
power controllers and that the array
controllers are on.
2.
3.

Ensure that there are at least four
operational power supplies.
Check the array controller optional
system maintenance terminal for error
messages.

UltraSCSI RAID Enclosure 2–17

Operating the UltraSCSI Enclosure

SBB Shelf Status
The two green LEDs on each power supply (see Figure 2–5) display the
blower, the power bus, and the individual power supply status. Normally,
both these LEDs are ON.
The shelf status LED is ON when all the power supplies and all the blowers
are operational. When any blower or power supply fails, this LED is OFF.
Figure 2–5 Shelf Status LEDs

Shelf
status LED
(Green)
Power supply
status LED
(Green)

CXO-4787A-MC

The power supply status LED is ON when the power supply is operating
properly
For detailed information about the power supply status LEDs, see Chapter
6, “Power Distribution.”

SBB Configuration
Part of the initial configuration procedure for the subsystem involves
configuring the disk drives so that the array controllers know the device
type, physical location, and logical location. This information is the basis
for the array controller transferring data blocks to specific disks to create
storage sets. Once the configuration process is complete, the system cannot
function properly unless all the disks remain in the same physical and
logical location.
The enclosure automatically notifies the array controller of the removal of a
device. This ensures that the array controller can implement the following
actions.

2–18 Ultra SCSI RAID Enclosure

Operating the UltraSCSI Enclosure

•

When data is not being transferred, there is no array controller response
to SBB removal.

•

When data is being transferred, the array controller responds to SBB
removal by verifying the data validity.

When you install a replacement device in a configured subsystem, the array
controller ensures that the replacement device type is identical to the one
removed. Only after establishing complete compatibility can the array
controller start configuring the SBB. As part of the configuration process
the array controller will restore all data that was on the original disk.

SBB Failure
The LEDs on the SBBs (Figure 2–6) display the status of the individual
devices. The SBB green device activity LED flashes whenever the SBB is
active.
Figure 2–6 SBB Status LEDs

Device
activity
(Green)
Device
fault
(Amber)

CXO-4652A-MC

Whenever the array controller detects a device error condition it causes the
amber device fault LED to flash. This LED is only ON or FLASHING when
there is a device malfunction.
For detailed information about the SBB status LEDs, see Chapter 7,
“Storage Devices.”

UltraSCSI RAID Enclosure 2–19

SES Template Word 7 Blank Page Fix by Peter LaQuerre

3
Environmental Monitoring Unit
(EMU)
The primary function of the EMU (Figure 3–1) is to monitor, process,
report, and display power distribution, temperature, blower, configuration,
SCSI addressing, I/O module, communications, and microcode status
information. The EMU and the array controller can exchange and process
some of this information.
Figure 3–1 EMU

CXO-5497A-MC

___________________ Caution _____________________
Proper operation of an UltraSCSI subsystem requires an
operational EMU and PVA in each enclosure. You must also
establish communications links between the EMUs to ensure
proper subsystem operation and error reporting.
________________________________________________

UltraSCSI RAID Enclosure 3–1

Environmental Monitoring Unit (EMU)

Product Description
The EMU identifies enclosure error conditions and configuration faults, and
notifies the user of existing or impending failures, using one or more of the
following error reporting systems:
•

EMU LEDs

•

EMU audible alarm

•

Error messages on the host interface

•

Enclosure LEDs

The EMU mounts directly above controller “A” (upper) bus controller (see
Figure 3–2).
Figure 3–2 EMU Location

EMU

PVA
CXO5754A

3–2 UltraSCSI RAID Enclosure

Environmental Monitoring Unit (EMU)

In some instances, such as a blower failure, a high intake air temperature, or
a high internal enclosure (exhaust) temperature, the EMU can automatically
initiate a corrective action. For example, operating the blowers at high
speed. When there is the possibility of component damage due to
overheating, the EMU can turn off the enclosure power.
_____________________ Note ______________________
Unless the array controller is shut down, the EMU cannot place
the enclosure into the standby power mode due to an
overtemperature.
When the array controller is operational, an overtemperature
condition causes the EMU to turn the enclosure power OFF.
When the master enclosure has an overtemperature condition,
clearing the cache module prior to turning off the power does
not occur.
________________________________________________

Controller Status
The master EMU monitors the state of both array controllers. Should the
EMU detect a controller fault it can implement the following actions:
•

Sound the audible alarm

•

Cause the EMU system fault status LED to flash

•

Display a controller fault code on the blower LEDs after you
momentarily press the alarm control switch
_____________________ Note ______________________
An error on the EMU–array controller communications path can
also cause a controller fault.
________________________________________________

UltraSCSI RAID Enclosure 3–3

Environmental Monitoring Unit (EMU)

I/O Module Status
The EMU also ensures that the six I/O modules are present, properly
installed, and communicating with the backplane, and that TERMPOWER
is at the correct level. The EMU reports an error condition whenever any of
these conditions occurs. The EMU also reports the I/O module type to the
array controller. Should the controller determine that the all modules are not
the same type, it can display this information on the optional maintenance
terminal.
An integrated circuit on each I/O module functions as a bus expander. The
EMU and the array controller can enable or disable this circuit on an
individual I/O module, thereby controlling individual external SCSI buses.

Enclosure Configuration Information
The EMU maintains the following configuration information:
•

Enclosure number (the PVA SCSI ID setting)

•

EMU microcode revision

•

EMU message protocol revision

•

Temperature sensor set points

•

The number of installed power supplies by location

•

The number of installed SBBs by location

•

The number of operational blowers in each bank

3–4 UltraSCSI RAID Enclosure

Environmental Monitoring Unit (EMU)

EMU Front Panel
The EMU user interface controls, connectors, and LED displays are on the
front panel. Use Figure 3–3 and the following sections to identify, and
determine the function of each component.
Figure 3–3 EMU Major Component Locations
1

CXO5774A

EMU communications connector

System fault LED (amber) and alarm control switch

Temperature fault LED (amber).

Power status LED (green)

RS232 Connector

Blower fault LEDs (amber)

EMU communications connector

EMU Communications Connectors
A connector (CALLOUTS 1 and 7) for EMU—EMU communications.
System Fault LED and Alarm Control Switch
The amber system fault LED in the alarm control switch (CALLOUT 2) is ON
whenever an error condition exists.

UltraSCSI RAID Enclosure 3–5

Environmental Monitoring Unit (EMU)

•

This LED is FLASHING whenever the EMU has one or more fault codes
to display.

•

When the alarm control LED is FLASHING, momentarily pressing the
EMU alarm control switch turns OFF the audible alarm and starts the
fault code LED display.

•

Pressing the alarm control switch for at least 5 seconds clears all the
active fault codes. Detection and the display of new faults continue.

•

When in the standby power mode, momentarily pressing this switch
will restore power to the enclosure.

Temperature Fault LED
Whenever either the intake or the exhaust air temperature exceeds the
user-defined temperature setpoints, this amber LED (CALLOUT 3) is ON until
the overtemperature condition is corrected.
Power Supply Status LED
This green LED (CALLOUT 4) is ON whenever ALL the following conditions
exist:
•

+5 V dc is greater than +4.7 V dc.

•

+12 V dc is greater than +11.4 V dc.

•

At least four power supplies are operational.

•

TERMPOWER is present on all six I/O modules.

This LED is OFF whenever any ONE of the following conditions exists:
•

+5 V dc is less than +4.7 V dc.

•

+12 V dc is less than +11.4 V dc.

•

Fewer than four power supplies are operational.

•

One or more I/O modules are missing TERMPOWER

RS232 Connector
You can connect a maintenance terminal console or PC to connector
(CALLOUT 5) to display EMU:
•

Error messages.

•

Information messages.

A PC can also load the microcode updates into the EMU memory through
this connector.
3–6 UltraSCSI RAID Enclosure

Environmental Monitoring Unit (EMU)

Blower Fault LEDs
One or more of these eight, amber blower fault LEDs (CALLOUT 6) are ON
whenever one of the following conditions exists:
•

One or more blowers are not operating.

•

One or more blowers are not operating at the correct speed.

•

Removal of a blower

The blower LEDs are also on when there is a configuration fault.

Configuring the EMU
Configuring the EMU requires connecting the EMU—EMU
communications bus and then using the CLI (command line interpreter)
set emu command to establish the temperature set points and the blower
speed operating mode.

UltraSCSI RAID Enclosure 3–7

Environmental Monitoring Unit (EMU)

Connecting the EMU Communication Bus
In an expansion configuration you must establish communications between
the master EMU and each expansion EMU. To establish communications
you must connect a communication port on each EMU to a communication
port on another EMU (see Figure 3–4). By establishing an EMU—EMU
communication bus you ensure that the master EMU can monitor and
control all the enclosures in the UltraSCSI subsystem.
Figure 3–4 EMU Communication Connections

CXO5820A

DIGITAL recommends that use a BN26M cable (see Table 3–1) no longer
than 4 m (13.1 ft) to connect the EMUs.
Table 3–1 EMU Communication Cables
Length

Part

Description

Meters

Feet

Number

8-conductor 24 AWG, PVC, round cable assembly
with:
2–8 position (8MP). locking, plug connectors

0.2
0.5
1.0
3.0
4.0

0.7
1.0
1.6
9.8
13.1

BN26M–0B
BN26M–0E
BN26M–01
BN26M–03
BN26M–04

CXO5747A

3–8 UltraSCSI RAID Enclosure

Environmental Monitoring Unit (EMU)

EMU Firmware
The EMU firmware enables you to use CLI commands to establish limits
for EMU functions such as temperature and blower speed control. The
different versions determine the specific commands or functions available.
The EMU compares the temperature sensor readings and the blower speed
readings against the limits you entered.
When the EMU controls blower speed, it will automatically place the
blowers into the high-speed mode when the any sensor reports a
temperature that is within 4°C (7°F) of the sensor setpoint. For example, if a
temperature set point is 41°C (106°F), the EMU would cause the blowers to
operate at high speed when the temperature reaches 37°C (99°F). The
blowers operating at high-speed should prevent an overtemperature
condition occurring and shutting down the enclosure.
You must use the following CLI commands to set the temperature set point
for each EMU:
set emu sensor_1_setpoint=48
set emu sensor_2_setpoint=48
set emu sensor_3_setpoint=41
Where: 1 = backplane sensor 1 (exhaust)
2 = backplane sensor 2 (exhaust)
3 = EMU sensor (intake)
DIGITAL recommends that use these set points.
___________________ Caution _____________________
For EMU firmware versions 1.0 and 1.1 you cannot use the
command: set emu sensor_n_setpoint=default.
This command will establish a temperature set point that is too
low for proper operation. This can result in an erroneous
subsystem alarm.
Removing and replacing the master EMU automatically changes
the temperature set points to the default setting. You must then
set all the temperature set points using the CLI commands.
________________________________________________

UltraSCSI RAID Enclosure 3–9

Environmental Monitoring Unit (EMU)

Setting the Temperature Sensors
There are three temperature sensors in each UltraSCSI enclosure
•

Two on the rear of the backplane in the top middle

•

One mounted on the EMU module

You have the option of setting the temperature at which an individual sensor
reports an overtemperature condition. You enter the desired temperature in
degrees Celsius (°C) within the range of 0°C (32°F) through 49°C (120°F).
See Table 3–2 for the relationship between °C and °F (Fahrenheit). Always
use the rules in Table 3–3 when setting the temperature set points.
The EMU sensor monitors the EMU air temperature, while the two
enclosure sensors monitor the exhaust air temperature. The exhaust air
temperature is higher than the EMU air temperature.
In an expansion configuration you can only set the master EMU
temperatures. The temperature set points for the other UltraSCSI enclosures
automatically change to match the master EMU setting.
______________________Note _____________________
For detailed instructions about using the set emu commands,
refer to the array controller CLI documentation.
________________________________________________

3–10 UltraSCSI RAID Enclosure

Environmental Monitoring Unit (EMU)

Table 3–2 EMU Set Point Temperature Conversions
°F

°C

°F

°C

°F

°C

°F

°C

°F

°C

104

106

108

109

111

113

115

117

100

118

102

120

UltraSCSI RAID Enclosure 3–11

Environmental Monitoring Unit (EMU)

Table 3–3 Temperature Set Point Rules
1.

Enter all temperatures in degrees Centigrade (°C). You cannot enter
temperatures as fractions, decimals, or degrees Fahrenheit (°F).

The EMU set point (sensor_3) temperature must be a minimum of
6°C (11°F) greater than the highest expected ambient (intake)
temperature.

The backplane set points (sensor_1 and sensor_2) must be a
minimum of 13°C (23°F) greater than the highest expected ambient
temperature. (7°C [13°F] greater the EMU set point).

The backplane set points (sensor_1 and sensor_2) must be the same
temperature.

When operating with EMU firmware versions 1.0 or 1.2, you cannot
use the command:
set emu sensor_n_setpoint=default.

When operating with EMU firmware versions 1.0 or 1.2, you must
use the commands set emu sensor_n_setpoint=nn, where
nn is the temperature in °C.

3–12 UltraSCSI RAID Enclosure

Environmental Monitoring Unit (EMU)

Setting the Blower Speed Control
The UltraSCSI enclosure blowers normally operate at low speed and
provide sufficient air flow to cool the enclosure components and ensure
proper operation. Use the CLI set emu fanspeed command to change
the operating speed of the blowers.
•

When you enter set emu fanspeed=high, all blowers in all
enclosures operate at high speed.

•

When you enter set emu fanspeed=automatic, the local EMU
controls the blower speed in each enclosure.
_____________________ Note ______________________
For detailed instructions about using the set emu commands,
refer to the array controller documentation.
________________________________________________

DIGITAL recommends using the set emu fanspeed=automatic so
that each EMU can implement corrective action whenever one of the
following error conditions occurs:
•

A blower fails

•

You remove a blower

•

A blower is rotating too slowly to provide sufficient air flow

•

The intake air temperature exceeds the user defined temperature

•

Either backplane temperature exceeds the user defined temperature

DIGITAL suggests using set emu fanspeed=high whenever the
following conditions exist:
•

The intake temperature is more than 38°C (100°F)

•

There is no air conditioning

•

Both conditions exist

When the EMU detects a blower or temperature error condition it can
automatically switch all the operational blowers to high speed. This thereby
increases the air flow through the enclosure and reduces the possibility of
component failure. Simultaneously, the EMU can initiate the following
actions:
•

Enable the audible alarm on the EMU

UltraSCSI RAID Enclosure 3–13

Environmental Monitoring Unit (EMU)

•

Turn on the amber system fault LED whenever the temperature exceeds
a set point

•

Turn on the amber temperature fault LED

•

Notify the array controller of the error condition

•

Start the EMU timer when (1) all blowers in a bank are defective, or
(2) a blower is removed

•

Eight minutes after the EMU timer begins operating, turn off the dc
power in the enclosure to prevent component overheating

When you momentarily depress the alarm control switch the EMU audible
alarm will turn OFF and the fault status LEDs remain ON. At this time the
blower LEDs will display the system fault codes (“Configuration Fault
Code Reporting”).

EMU Status Reporting
The EMU processes subsystem status reports and notifies the user of
problems using the EMU audible alarm and the status LEDs (system,
temperature, power, blower). See Figure 3–5.
Figure 3–5 EMU Status LEDs

System
fault

Power

Temperature

Blowers

Alarm control
switch
CXO5748A

3–14 UltraSCSI RAID Enclosure

Environmental Monitoring Unit (EMU)

The EMU processes two types of problems:
•

An error condition involving the failure of a component or conditions
outside the predetermined environment, such as an overtemperature
condition.
When there is an error condition the system fault LED is ON. For
detailed information about system fault LEDs, see “Error Condition
Reporting,” on page 3–17.

•

A fault condition involves a subsystem configuration problem, such as
a Boot ROM checksum failure.
When there is a fault condition the system fault LED is FLASHING. For
detailed information about the system fault LED, see “Configuration
Fault Code Reporting.”

Whenever the audible alarm sounds, the user should check the EMU status
LEDs to determine the problem.
___________________ Caution _____________________
Should the audible alarm sound but the status LEDs not indicate
an error condition, it is possible that the error condition no
longer exists. However, you should always check the error log
on the maintenance terminal to ensure that the error no longer
exists.
________________________________________________
The EMU reports the system status, to include error conditions, to the array
controller that records some of this information in the error log and displays
it on the controller console.

Alarm Control Switch
Whenever a power, environment, blower error, or fault condition occurs the
EMU turns on the local audible alarm. At the same time the alarm sounds,
an amber LED in the alarm control switch turns ON. The alarm remains on
until one of the following conditions occurs:
•

Correction of the error condition

•

The user momentarily presses the alarm control switch

When you momentarily press the switch you turn off the audible alarm for
all current fault conditions in the local subsystem. The alarm remains OFF
until one of the following conditions occur:

UltraSCSI RAID Enclosure 3–15

Environmental Monitoring Unit (EMU)

•

A different fault occurs

•

An existing fault clears and reoccurs

•

An error condition still exists after 1 hour. This causes he audible alarm
to sound for approximately 5 seconds once every hour.

When you press and hold the switch for at least 5 seconds you clear all the
fault codes displays.
______________________Note _____________________
The alarm control switch does not affect either the error
condition or the error condition code stored by the EMU. The
only way to clear this stored error condition code is to correct
the problem.
________________________________________________
The alarm control switch functions as an enclosure power switch when the
standby power mode is active. You must press the alarm control switch to
restore dc power to the enclosure.

Subsystem Status LEDs
Table 3–4 shows the possible EMU status LED displays. When the LED
blinking or flashing interval is more than 1 second, the LED is ON.
Table 3–4 Subsystem Status LEDs Displays
Symbol

Condition

LED is ON or blinking slowly
LED is OFF.
LED is FLASHING (blinking rapidly)

3–16 UltraSCSI RAID Enclosure

Environmental Monitoring Unit (EMU)

Monitoring Power Supply Operation
Even when there are four operational power supplies, it is possible that a
power supply problem will cause one or both of the dc voltages to be too
low. Both the PVA and the EMU monitor power supply operations to ensure
that the dc voltages are within the ranges specified in Table 3–5.
Table 3–5 DC Voltage Ranges
Nominal Voltage

+ 5 V dc

+ 12 V dc

Minimum Voltage

+4.7 V dc

+ 11.4 V dc

When there are at least four operational power supplies both the minimum
voltages, which are sufficient to run the system, are present. Fewer than
four operational power supplies cannot maintain the minimum voltages.
Should this occur, the EMU will notify the array controller. The EMU can
automatically initiate the standby power mode when controller directs or the
PVA .
_____________________ Note ______________________
Only the EMU monitors the I/O module +5 V dc
TERMPOWER. The PVA does not monitor these voltages.
________________________________________________

Error Condition Reporting
The EMU LEDs (see Table 3–6) display the enclosure, the temperature
status, error conditions, individual blowers status, and blower bank status
(When the enclosure is functioning properly only the Power LED is on.)
The figures describe:
•

The EMU LED display

•

The enclosure status associated with each display

•

The probable cause of the error condition

•

The actions recommended to correct the problem

UltraSCSI RAID Enclosure 3–17

Environmental Monitoring Unit (EMU)

______________________Note _____________________
It is not practical to display all the possible LED display
combinations. For example, there are eight displays for the
failure of an individual blower. Therefore, Table 3–6 lists only a
representative sampling of the possible displays.
________________________________________________
Table 3–6 EMU Status Displays
EMU Status

EMU LED Display

Operational Enclosure

The subsystem is fully operational.

The power supplies and the blowers
are functioning properly. The intake
and exhaust air temperatures are
within the user specified limits.

CXO5778A

Non-Operational Enclosure
8

CXO5780A

Probable Cause 1—Either +5 V dc or 12 V dc out of range. Observe the power supply status
LEDs to determine the defective power supply and replace it.
Probable Cause 2—TERMPOWER less than +4.5 V dc on one or more I/O modules. Replace the
I/O modules with a TERMPOWER LED OFF

3–18 UltraSCSI RAID Enclosure

Environmental Monitoring Unit (EMU)

Table 3–6 EMU Status Displays (Continued)
EMU Status

EMU LED Display

Overtemperature Condition
8

CXO5779A

Probable Cause 1—A temperature in one or more enclosures is above the user specified limit.
Determine and correct the cause of this condition quickly prevent the overtemperature condition
from causing a subsystem RESET or failure.
Probable Cause 2—A temperature set point is too low for environment. Change temperature set
point.
Single Blower Fault

Operational blowers are running at
high speed.

CXO5781A

Probable Cause—A blower in either bank, or both banks, is not operating properly.
Replace the defective blowers.
Comment—In this example blower 1 and 7 are not operating.

UltraSCSI RAID Enclosure 3–19

Environmental Monitoring Unit (EMU)

Table 3–6 EMU Status Displays (Continued)
EMU Status

EMU LED Display

Missing Blower Fault
or
Multiple Blower Faults

Operational blowers are running at
high speed.
CXO5782A

Probable Cause 1—A blower is removed. Replace the missing blower.
Probable Cause 2—All blowers in one bank are not operating. Remove and install blowers
correctly within 8 minutes.
Probable Cause 3—Multiple blowers are installed incorrectly. Remove and install blowers
correctly within 8 minutes.
Comment—In this example, one of the following conditions exists in Bank 1:
• A blower is removed.
or
•

Two or more blowers are not operating.

Failure to replace the missing blower within 8 minutes can result in the enclosure entering the
standby power mode.
Configuration Error
8

CXO5783A

Probable Cause 1—Configuration error. See “Configuration Fault Code Reporting” for the
specific error condition.
Probable Cause 2—Slave EMU cannot communicate with Master EMU. See “Configuration
Fault Code Reporting” for the specific error condition.
Probable Cause 3—External SHELF_OK signal indicates error. See “Configuration Fault Code
Reporting” for the specific error condition.

3–20 UltraSCSI RAID Enclosure

Environmental Monitoring Unit (EMU)

Configuration Fault Code Reporting
The system fault, temperature, power, and blower LEDs, cannot display all
the possible system faults. Therefore, a FLASHING system fault LED
indicates that there are system faults. To determine what the system fault is
you must observer the hexadecimal code displayed on the blower LEDs in
binary format. The upper LEDs (8 through 5) display the first digit (the
most significant digit); the lower LEDs (4 through 1) display the second
digit (the least significant digit).
_____________________ Note ______________________
Until you momentarily press the FLASHING alarm control switch,
the blower LEDs cannot display the fault codes.
________________________________________________
Each time you momentarily press the alarm control switch, the EMU
initiates the following actions:
1.

Displays the first reported hexadecimal fault code on the blower LEDs
three times in succession.
•

The LEDs display the first reported fault code the first time for one
second and then go OFF.

•

The LEDs display the first reported fault code the second time for
one second and then go OFF.

•

The LEDs display the first reported fault code the third time for
one second and then go OFF.

The LEDs now display the next reported fault code three times.

Steps 1 and 2 repeat for all fault codes.

For a detailed explanation of the fault codes see Table 3–7.

UltraSCSI RAID Enclosure 3–21

Environmental Monitoring Unit (EMU)

Table 3–7 EMU Fault Code Displays
Fault Code, Cause,
Corrective Action

EMU LED Display

Fault Code 01

One of the following Boot ROM
error conditions exist:

CXO5760A

1.
2.

A Boot ROM Signature failure. Replace the EMU.
A Boot ROM Checksum failure. Replace the EMU.

Fault Code 02

Both microcode images are bad.
1. Load microcode image to the
EMU from the PC.
2. Replace the EMU.

CXO5761A

Fault Code 03

Either a PVA SCSI ID switch setting
is invalid (1, 4, 5, 6, or 7) or there is
no master enclosure (SCSI ID 0).

CXO5762A

2.
3.

Ensure PVA SCSI ID switches settings are as follows:
• Master enclosure–0.
• First expansion enclosure–2.
• Second expansion enclosure–3.
If you change any PVA SCSI ID switch setting, turn the system OFF, and then turn the system
ON.
Replace each of the PVAs in sequence until the fault condition clears.

3–22 UltraSCSI RAID Enclosure

Environmental Monitoring Unit (EMU)

Table 3–7 EMU Fault Code Displays (Continued)
Fault Code, Cause,
Corrective Action

EMU LED Display

Fault Code 04

Master EMU cannot communicate
with expansion EMU.

CXO5763A

2.
3.
4.
5.

Ensure PVA SCSI ID switches settings are as follows:
• Master enclosure–0.
• First expansion enclosure–2.
• Second expansion enclosure–3.
If you change any PVA SCSI ID switch setting, turn the system OFF, and then turn the system
ON.
Ensure the EMU cables are properly connected.
Disconnect each EMU cable and connect them one at a time. Replace the defective cable.
Replace the EMU.

Fault Code 05 Master

EMU cannot communicate with array
controller.
1. Replace the EMU.
2.

CXO5764A

Replace the array controller

Fault Code 06

2.
3.

One or more temperature sensors
indicating an “invalid”
temperature–one that is greater
than 49°C (120°F).

CXO5765A

Replace the EMU.
Have field service replace temperature sensor.

UltraSCSI RAID Enclosure 3–23

Environmental Monitoring Unit (EMU)

Table 3–7 EMU Fault Code Displays (Continued)
Fault Code, Cause,
Corrective Action

EMU LED Display

Fault Code 07

Invalid configuration.

Requires an array controller specific
action.
CXO5766A

Fault Code 08

Two PVA SCSI ID switch settings
are the same.

CXO5767A

2.
3.

Ensure the PVA SCSI ID switch settings are as follows:
• Master enclosure–0.
• First expansion enclosure–2.
• Second expansion enclosure–3.
If you change any PVA SCSI ID switch setting, turn the system OFF, and then turn the system
ON.
Replace each of the PVAs in sequence until the fault condition clears.

Fault Code 09

EMU installed in PVA slot.

Install the EMU in the slot on the left
using the procedure in Table 3–9.
CXO5768A

Fault Code 0A

No PVA installed.

Install the PVA using the procedure
in Table 4–7
CXO5769A

3–24 UltraSCSI RAID Enclosure

Environmental Monitoring Unit (EMU)

Table 3–7 EMU Fault Code Displays (Continued)
Fault Code, Cause,
Corrective Action

EMU LED Display

Fault Code 0B

Controller fault.

Requires an array controller specific
action (see the array controller
documentation).

CXO5770A

Fault Code 0C

One or more defective power
supplies.

Observe all power supply status
LEDs. Replace any power supply
with the lower LED OFF

CXO5771A

Fault Code 0D

Master enclosure SCSI ID address
incorrect or array controller installed
in expansion enclosure.

CXO5772A

Change the master enclosure SCSI ID to 0 and turn the system OFF, and then turn the system
ON.

Install the array controller in the master enclosure.

Fault Code 0E

EMU memory test failed.

Replace the EMU
CXO5773A

UltraSCSI RAID Enclosure 3–25

Environmental Monitoring Unit (EMU)

Table 3–7 EMU Fault Code Displays (Continued)
Fault Code, Cause,
Corrective Action
Fault Code 0F

Less than four operational power
supplies.
Replace the defective power supplies.

EMU LED Display
Initial Display
8

Comment—The EMU places the
system in the standby power mode

CXO5784A

Standby Power Mode Display
8

CXO5815A
Fault Code 10

EMU diagnostic program loaded.

The audible alarm is on continuously
and you cannot clear it by pressing
CXO5814A
the alarm control switch.
1. Load new microcode, turn the system OFF, and then turn the system ON.
2. Replace the EMU with one with proper microcode, turn the system OFF, and then turn the
system ON.

3–26 UltraSCSI RAID Enclosure

Environmental Monitoring Unit (EMU)

Replacing an EMU
To remove an EMU complete the procedure in Table 3–8. To install an
EMU complete the procedure in Table 3–9.
Table 3–8 Removing an EMU
1.

Shut down the system by clearing the cache module and shutting down the controller.

Turn Off the enclosure power.

Pull the extractor latches forward and remove the EMU.

CXO-5497A-MC

Table 3–9 Installing an EMU
1.

Remove the EMU from the shipping container and ensure that it is a model DS–BA35X–EB.

CXO-5497A-MC

UltraSCSI RAID Enclosure 3–27

Environmental Monitoring Unit (EMU)

Table 3–9 Installing an EMU (Continued)
2.

Align the EMU with left hand slot.

EMU

PVA
CXO5754A

Insert the EMU into the slot and push it in until the extractor latches engage the enclosure.

For an expansion configuration use a BN26M-series cable (see Table 3–10) to connect the
EMU—EMU communications bus.

After installing all components, apply power to the expansion enclosures.

Apply power to the master enclosure and after the controller is operational, verify that the
subsystem is functioning properly.

CXO5820A

3–28 UltraSCSI RAID Enclosure

Environmental Monitoring Unit (EMU)

Table 3–10 EMU Communications Cables
Length

Part

Description

Meters

Feet

Number

8-conductor 24 AWG, PVC, round cable assembly
with:
2 each, 8 position (8MP) locking, plug
connectors

0.5
1.0
3.0
4.0
7.0

1.0
1.6
9.8
13.0
23

BN26M–0E
BN26M–01
BN26M–03
BN26M–04
BN26M–07

CXO5747A

UltraSCSI RAID Enclosure 3–29

SES Template Word 7 Blank Page Fix by Peter LaQuerre

4
Power Verification and
Addressing (PVA)
The PVA (power verification and addressing) assembly (Figure 4–1) and the
associated EMU monitors the status of the major UltraSCSI enclosure
components to verify proper operation. When an error or fault condition
occurs, these modules notify the user, and, in some instances, the array
controller, that a problem exists. The array controller can identify and
display information about some problems. The PVA and EMU LED
displays identify possible problem causes.
Figure 4–1 PVA

CXO-5737A

___________________ Caution _____________________
Proper operation of an UltraSCSI subsystem requires an
operational EMU (model DS–BA35X–EB) and PVA (model
DS–BA35X–EC) in each enclosure. You must also establish
communications links between the EMUs to ensure proper
subsystem operation and error reporting.
________________________________________________
UltraSCSI RAID Enclosure 4–1

Power Verification and Addressing (PVA)

The PVA and EMU mount next to each other in the enclosure—the EMU
on the left and the PVA on the right (see Figure 4–2).
Figure 4–2 PVA Location

EMU

PVA
CXO5754A

Product Description
Figure 4–3 identifies the major PVA components.
Figure 4–3 PVA Major Components
1

CXO5821A

Standby power switch.

Communications port (unused)

Enclosure SCSI address switch

4–2 UltraSCSI RAID Enclosure

Power Verification and Addressing (PVA)

The PVA has two status indicators:
•

A green power status LED in the power switch
This LED is ON
whenever both there at least four operational power supplies. When an
error condition occurs, the LED is OFF.
This switch can initiate the standby power mode when the array
controller is inactive. In this mode, ac power is applied to the power
controllers and the power supplies. However, the shelf power supplies
dc outputs are not distributed.

•

An audible alarm that beeps slowly when the PVA detects removal of
the EMU. This beep reminds the user to install an operational EMU to
restore the subsystem to an operational status.

Functions
The primary functions of the PVA include the following:
•

Ensuring there are at least four operational power supplies in the
enclosure

•

Notifying the array controller when there are less than four operational
power supplies in the master enclosure. The array controller may then
initiate a RESET
This duplicates an EMU function and ensures optimum subsystem
performance and integrity.

•

Allowing the user to select a DIGITAL supported device SCSI bus
address (device ID) for each enclosure

•

Monitoring the enclosure EMU status and notifying the user when the
EMU is missing

PVA Operation
Most PVA operations occur automatically and do not require any user
intervention. The following sections define major PVA operations.

EMU Installation Monitoring
Should you remove the EMU, or install it incorrectly (for example, not
seating it fully), the PVA detects this condition and sounds the PVA audible
alarm. This alarm will beep slowly until the PVA senses the presence of an
operational EMU.

UltraSCSI RAID Enclosure 4–3

Power Verification and Addressing (PVA)

____________________ Caution ____________________
Removing both the EMU and PVA at the same time will cause
the system to RESET.
________________________________________________

SBB Device IDs
The 24 disk drives in each enclosure are arranged on six vertical buses in
four horizontal shelves. All six devices on the same horizontal shelf use the
same device address or ID. See Figure 4–4 for the master enclosure SBB
device IDs.
Figure 4–4 Master Enclosure Device IDs
1

SCSI bus
3
4

3
2
1
0
CXO5755A

____________________ Caution ____________________
To preclude SCSI bus addressing conflicts, DIGITAL only
supports enclosure address settings 0, 2, and 3.
________________________________________________

4–4 UltraSCSI RAID Enclosure

Power Verification and Addressing (PVA)

Use the PVA address switch to establish SCSI bus IDs for all the devices on
the same shelf. This switch has eight (0 through 7) positions.
Always set the master enclosure switch is to 0.

Monitoring Power Supply Operation
Even when there are four operational power supplies, it is possible that a
power supply problem will cause one or both of the dc voltages to be too
low. Both the PVA and the EMU monitor power supply operations to ensure
that the dc voltages are within the ranges specified in Table 4–1
Table 4–1 DC Voltage Ranges
Nominal Voltage

+ 5 V dc

+ 12 V dc

Minimum Voltage

+4.7 V dc

+ 11.4 V dc

When there are at least four operational power supplies both the minimum
voltages, which are sufficient to run the system, will be present. Fewer than
four operational power supplies cannot maintain the minimum voltages.
Should this occur, the EMU will notify the array controller. The EMU can
automatically initiate the standby power mode.
_____________________ Note ______________________
Only the EMU monitors the system dc voltages and the I/O
module +5 V dc TERMPOWER. The PVA only monitors the
system dc voltages.
________________________________________________

UltraSCSI RAID Enclosure 4–5

Power Verification and Addressing (PVA)

Setting the Enclosure Address
Use the procedure in Table 4–2 to identify the enclosure as either a master
or an expansion enclosure. This switch also establishes the SCSI bus address
(device ID) for the disk drives (SBBs) in the enclosure. The following
restrictions apply to establishing the enclosure address:
1.

The master enclosure address is always 0.

There is only one master enclosure in any subsystem.

No two enclosures can have the same address.

See Table 4–3 for the DIGITAL-supported enclosure addresses.
____________________ Caution ____________________
DIGITAL does not support any combination of enclosure
address settings that assign the same SCSI bus device address to
more than one device on a SCSI bus
To preclude SCSI bus addressing conflicts, DIGITAL only
supports enclosure address settings 0, 2, and 3.
________________________________________________
Table 4–2 Setting the Enclosure Configuration
DECREASE
SWITCH

To decrease the configuration number:
Press the upper switch to step the address
down one address at a time (decrement).

0
To increase the configuration number:
Press the lower switch to step the address
up one address at a time (increment).
INCREASE
SWITCH
CXO-4851A-MC

____________________ Caution ____________________
To implement an address setting change you must turn the
enclosure OFF and then turn it ON.
________________________________________________
4–6 UltraSCSI RAID Enclosure

Power Verification and Addressing (PVA)

Table 4–3 DIGITAL Supported Enclosure Addresses
No. of Enclosures

Master

Expansion 1

Expansion 2

None

Master Enclosure Address
The master enclosure address is always 0 that establishes the SBB SCSI bus
IDs shown in Figure 4–5.
Figure 4–5 Master Enclosure SCSI Bus IDs
1

SCSI bus
3
4

CXO-4840A-MC

2
1
0
CXO5755A

UltraSCSI RAID Enclosure 4–7

Power Verification and Addressing (PVA)

Expansion Enclosure Addresses
DIGITAL supports only expansion enclosure address settings 2
(see Figure 4–6) and 3 (see Figure 4–7).
____________________ Caution ____________________
To preclude SCSI bus addressing conflicts, DIGITAL does not
support enclosure address settings 1, 4, 5, 6, or 7 for systems
with HSZ70-series controllers.
________________________________________________
Figure 4–6 Enclosure Address 2 SCSI Bus IDs
1

SCSI bus
3
4

CXO-4842A-MC

10
9
8
CXO5776A

4–8 UltraSCSI RAID Enclosure

Power Verification and Addressing (PVA)

Figure 4–7 Enclosure Address 3 SCSI Bus IDs
1

SCSI bus
3
4

CXO-4843A-MC

14
13
12
CXO5777A

Implementing the Standby Power Mode
A major function of the PVA is implementing the standby power mode.
This mode removes dc power from all components except the EMU alarm
control switch. In the standby power mode the EMU alarm control switch
now functions as a dc power switch. Complete the procedure in Table 4–4
to place the subsystem in the standby power mode. Complete the procedure
in Table 4–5 to restore dc power to each enclosure.

UltraSCSI RAID Enclosure 4–9

Power Verification and Addressing (PVA)

Table 4–4 Turning Off the DC Power Distribution
1.

Clear the cache module and shut down the array controller as
described in the array controller documentation.

CXO5821A

The enclosure EMU alarm control switches now function as the
subsystem power switch.

Table 4–5 Turning On the DC Power Distribution
1.

Momentarily press the EMU alarm control switch (CALLOUT 2) on
each expansion enclosure.
1

CXO5774A

Momentarily press the EMU Alarm control switch (CALLOUT 2) on
the master enclosure.

The array controller restores the subsystem to an operational state.

4–10 UltraSCSI RAID Enclosure

Power Verification and Addressing (PVA)

Replacing a PVA
Complete the procedures in Table 4–6 and Table 4–7 to replace a defective
PVA. Complete the procedure in Table 4–7 when assembling an UltraSCSI
RAID enclosure.
Table 4–6 Removing a PVA
1.

Shut down the array controller and turn off power in the enclosure.

Note the enclosure address setting on the thumbwheel switch.

Pull both extractor latches forward and remove the PVA.

CXO5737A

UltraSCSI RAID Enclosure 4–11

Power Verification and Addressing (PVA)

Table 4–7 Installing a PVA
1.

Remove the PVA from the shipping container and verify that it is a
model DS–BA35X–EC.

CXO5737A

Align the PVA with the right hand slot.

EMU

PVA
CXO5754A

Insert the PVA into the slot and push it in until the extractor latches
engage the enclosure.

Push in on the extractor latches to firmly seat the PVA.

Ensure that the enclosure address setting on the thumbwheel switch
is valid for the enclosure.

After installing all the components, apply power to the enclosure and
start the subsystem.

4–12 UltraSCSI RAID Enclosure

5
Single-Ended I/O Modules
The single-ended I/O modules (see Figure 5–1) have two functions:
•

Providing termination for both the internal and external SCSI buses

•

Establishing SCSI bus communications between

Figure 5–1 Single-Ended I/O Module

CXO5816A

___________________ Caution _____________________
Not all array controllers support an UltraSCSI RAID subsystem
with more than one enclosure. Read the array controller
documentation to ensure the controller supports expanded
configurations.
________________________________________________

UltraSCSI RAID Enclosure 5–1

Single-Ended I/O Modules

____________________ Caution ____________________
I/O modules provide termination for both the internal and the
external SCSI buses. Therefore, you must install the same type,
operational I/O modules on each of the six enclosure
connectors.
________________________________________________
The six I/O modules mount on the bottom rear (see Figure 5–2) of the
enclosure. These modules are the interconnection point between the array
controller in the master enclosure and the devices in the expansion
enclosures. In an UltraSCSI RAID subsystem, the I/O modules, the internal
SCSI buses, and the array controller ports all have the same number. For
example, array controller port 2, SCSI bus 2, and I/O module 2 are different
elements of the same logical bus.
Figure 5–2 I/O Module Location

2
4
6
5

3
Ports
CXO5805A

The odd numbered ports are in the bottom row and the even number ports
are in the top row (see Figure 5–3). Port 1 is in the lower right corner and
Port 6 is in the upper left corner.
Figure 5–3 I/O Module Numbering
6

1
CXO5819A

5–2 UltraSCSI RAID Enclosure

Single-Ended I/O Modules

Replacing I/O Modules and Cables
Replacing an I/O module or a cable without first shutting down the
controller can adversely affect data integrity. Removal of the I/O module
causes the EMU to report the following error conditions to the controller:
(1) Installation of different I/O modules. (2) Loss of TERMPOWER.
Either of these error conditions can cause the controller to cease operating
without implementing procedures to protect the data.
Before you remove an I/O module or an expansion cable, completion of the
of the following procedures is mandatory (1) Shut down the array
controller, and (2) Turn off the enclosure power. Failure to do so can
induce a controller error condition.

Expanding the UltraSCSI Bus
Each I/O module has a UltraSCSI single-ended bus expansion integrated
circuit that isolates the internal and external SCSI bus, enhances SCSI
signals, and extends the length of the UltraSCSI bus.
The two, 68-pin, VHDCI receptacle connectors are the connection points
for expanding the SCSI buses between enclosures. These connectors are
wired in parallel and can act as a trilink connector. In an expansion
configuration, DIGITAL recommends a maximum cable length of
2 m (6.3 ft) between enclosures.
_____________________ Note ______________________
Connecting a cable to the right I/O module connector removes
the external SCSI bus termination from the module.
_____________________________________________________

UltraSCSI RAID Enclosure 5–3

Single-Ended I/O Modules

Controlling the Internal SCSI Bus
The I/O module controls the internal SCSI bus in the following manner:
•

Isolates the internal SCSI bus from the external SCSI bus

•

Provides single-ended SCSI bus termination for each internal bus

•

Disconnects the internal SCSI bus from the external SCSI bus when the
EMU so directs

•

Distributes TERMPOWER (+5 V dc) to the internal SCSI bus

•

Turns ON the green internal TERMPOWER LED when internal
TERMPOWER is present

•

Turns OFF the green internal TERMPOWER LED when there is either
an internal TERMPOWER overcurrent condition or no TERMPOWER

Controlling the External SCSI Bus
The I/O module controls the external SCSI bus in the following manner:
•

Provides single-ended SCSI bus termination for the external bus

•

Distributes TERMPOWER (+5 V dc) to the external SCSI bus

•

Turns ON the green external TERMPOWER LED when external
TERMPOWER is present

•

Turns OFF the green external TERMPOWER LED when there is either
an external TERMPOWER overcurrent condition or no TERMPOWER

•

Disables the external bus termination when a cable is connected to the
right VHDCI connector

Controlling the Fault Bus
The I/O module controls fault bus operation in the following manner:
•

Provides a fault bus driver for improved signal transmission

•

Distributes the FAULT_CLK and FAULT_DATA signals from the
master enclosure to the expansion enclosures

•

Distributes the SHELF_OK and SWAP_L signals from the expansion
enclosures to the master enclosure

5–4 UltraSCSI RAID Enclosure

Single-Ended I/O Modules

Error Reporting
The EMU monitors the status of the I/O modules for the following error
conditions:
•

The installation of incompatible I/O modules

•

A TERMPOWER problem

Incompatible I/O Modules
An I/O module error condition exists whenever any of the following
conditions exists:
•

Fewer than six operational I/O modules are installed

•

The I/O modules are not the same type

When the EMU detects an error conditions it automatically reports the
problem to the controller. An operational controller will automatically turn
off without implementing procedures to clear the cache module. The result
is that the controller will cease to operate and be in an error state; a state
that can adversely affect the integrity of the data.
Only when all I/O modules are the same type can an UltraSCSI RAID
subsystem function properly. The DIGITAL UltraSCSI controller only
supports single-ended buses. Therefore, you can only use single-ended I/O
modules (DS–BA35X MN). The enclosure does not support the following
conditions:
•

Installing a single-ended I/O module improperly

•

Installing fewer than six single-ended I/O modules.

•

Installing a termination I/O module

•

Installing a differential I/O module

UltraSCSI RAID Enclosure 5–5

Single-Ended I/O Modules

TERMPOWER Errors
The I/O module displays the TERMPOWER status for both the internal and
the external bus (see Figure 5–4).
Figure 5–4 I/O Module TERMPOWER LEDs

External
TERMPOWER

Internal
TERMPOWER
CXO5829A

The nominal TERMPOWER for both buses is +5 V dc.
•

The green internal and external TERMPOWER LEDs are ON during
normal operation.

•

Whenever there is a TERMPOWER overcurrent condition or there is no
TERMPOWER, the associated LED is OFF.

See Table 5–1 for possible causes of TERMPOWER problems.
Table 5–1 TERMPOWER Problems
TERMPOWER Error

Possible Causes

Internal

I/O module
Power supply

External

I/O module
Power supply
External SCSI bus cable

Removing an I/O module disconnects the SCSI bus termination. The result
is there is no TERMPOWER available to the internal SCSI bus and the bus
cannot function correctly.

5–6 UltraSCSI RAID Enclosure

Single-Ended I/O Modules

Rules for Expanding an UltraSCSI Bus
By connecting the master enclosure to one or two expansion enclosures, you
can expand the SCSI bus from a 4-device bus to an 8-device or 12–device
bus. See Chapter 4, “Power Verification and Addressing Assembly,” for a
discussion of the valid enclosure SCSI bus addresses and the associated
array controller and storage device SCSI bus IDs.
___________________ Caution _____________________
The UltraSCSI bus can support a maximum of 16 devices (2
array controllers and 14 disk drives), However, DIGITAL does
not support any configuration with more than 12 disk devices.
This precludes creating device ID conflicts between the array
controllers and the disk drives, or between disk drives.
________________________________________________
To expand a SCSI bus, use the 68-pin VHDCI receptacle connectors on the
I/O module and a BN37A–series cable. See Table 5–2 for a list of the rules
for expanding and UltraSCSI bus.
___________________ Caution _____________________
The DIGITAL UltraSCSI controller does not support connecting
or disconnecting a SCSI bus when both data and power are
present on the connector, a "hot swap." You can only connect
or disconnect SCSI bus cables using the cold swap method.
To replace a cable, (1) Clear the cache module. (2) Shut down
the array controller, and (3) turn off the enclosure power before
removing an I/O module.
_____________________________________________________
_____________________ Note ______________________
Connecting a cable to the right I/O module connector removes
the external SCSI bus termination from the module.
_____________________________________________________

UltraSCSI RAID Enclosure 5–7

Single-Ended I/O Modules

Table 5–2 UltraSCSI Bus Expansion Rules
1.

The I/O module numbers (1–6) match the enclosure SCSI bus
numbers and the array controller port numbers.
6

1
CXO5819A

Always connect the cables between the I/O modules in the same
location on the same bus. That is, connect I/O module 1 on the
master enclosure to I/O module 1 on an expansion enclosure.

The first cable on any I/O module always connects to the left
connector.

The second cable on any I/O module always connects to the right
connector.

Cabling an UltraSCSI Subsystem
____________________ Caution ____________________
Not all array controllers support an UltraSCSI RAID subsystem
with more than one enclosure. Read the array controller
documentation to ensure the controller supports expanded
configurations.
________________________________________________
____________________ Caution ____________________
The DIGITAL UltraSCSI controller does not support connecting
or disconnecting a SCSI bus when both data and power are
present on the connector, a "hot swap." You can only connect
or disconnect SCSI bus cables using the cold swap method.
To replace a cable, (1) Shut down the array controller, and
(2) Turn off the enclosure power before removing an I/O
module.
____________________________________________________

5–8 UltraSCSI RAID Enclosure

Single-Ended I/O Modules

Before beginning the installation, you must complete the preliminary
procedures, select the UltraSCSI VHDCI cables, and shut down the
subsystem.

Preliminary Procedures
Complete the procedure in Table 5–3 before installing the cables.
Table 5–3 Preliminary Cabling Procedures
1.

Select the UltraSCSI cables for each segment based upon the distances
between the enclosures.

Determine the optimum route for each set of cables.

Shut down the array controllers.

Complete the installation procedure for either a two or three enclosure
subsystem.

UltraSCSI RAID Enclosure 5–9

Single-Ended I/O Modules

Selecting an UltraSCSI VHDCI Cable
You can use the cables listed in Table 5–4 to connect devices or cables with
68-pin VHDCI receptacle connectors.
Table 5–4 UltraSCSI Bus Cables
Length
Description

68-conductor SCSI cable with:
2–VHDCI
straight plug connectors with
jack screws.

Order

Meters

Feet

Number

0.3
0.5
1.0
1.5
2.0

1.0
1.6
3.3
4.9
6.6

BN37A–0C
BN37A–0E
BN37A–01
BN37A–1E
BN37A–02

CXO5702A

____________________ Caution ____________________
To ensure proper UltraSCSI bus operation, DIGITAL
recommends a maximum cable length of 2 m (6.3 ft).
________________________________________________

5–10 UltraSCSI RAID Enclosure

Single-Ended I/O Modules

Shutting Down the Subsystem
To protect data and the devices you must complete the procedures in
Table 5–5 before you begin installing the cables.
Table 5–5 Shutting Down the UltraSCSI Subsystem
1.

On the host dismount the UltraSCSI RAID subsystem disk drives.

Connect a maintenance terminal to an array controller.

Other controller
This controller

CXO5716A

Shut down the other array controller by entering the command—
shutdown other_controller.

Shut down the array controller by entering the command—
shutdown this_controller.

Shut down both array controllers.

Turn off all the ac power controllers in all the enclosures.

UltraSCSI RAID Enclosure 5–11

Single-Ended I/O Modules

Cabling a Three–Enclosure Subsystem
____________________ Caution ____________________
Not all array controllers support an UltraSCSI RAID subsystem
with more than one enclosure. Read the array controller
documentation to ensure the controller supports expanded
configurations.
________________________________________________
______________________Note _____________________
Each bus requires two BN37A cables, a total of 12 cables.
________________________________________________
Complete the procedure Table 5–6 for the I/O modules on each SCSI bus
starting with SCSI bus 1.
____________________ Caution ____________________
Overtightening the I/O module spring-loaded mounting screws
can damage the threads.
________________________________________________

5–12 UltraSCSI RAID Enclosure

Single-Ended I/O Modules

Table 5–6 Installing Three Enclosure Subsystem Cables
1.

Shut down the array controller (see Table 5–5).
Use a screwdriver to loosen the two, spring-loaded mounting screws
on the I/O module.

Grasp the module by the cable support bracket and pull it directly to
the rear and remove it from the enclosure shroud.

Repeat Steps 1 and 2 for all the I/O modules.

On the first (master) I/O module, align the Cable A connector with
the left connector.

CXO5816A

Cable A

CXO5854A

Gently insert the cable connector into module connector. Tighten
both cable connector thumb screws to fully seat the connector.
Install a wire tie through the holes on the cable support bracket and
around the cable. Tighten the wire tie.
5.

Align the module with the Port 1 backplane connector in the master
enclosure shroud. Gently insert the module and fully seat it. Use a
screwdriver to tighten the spring-loaded mounting screws.

UltraSCSI RAID Enclosure 5–13

Single-Ended I/O Modules

Table 5–6 Installing Three Enclosure System Cables (Continued)
6.

On an expansion I/O module, align the Cable A with the left
connector. Gently insert the cable connector into module connector.
Tighten both cable connector thumb screws to fully seat the
connector.
Install a wire tie through the holes on the cable support bracket and
around the cable. Tighten the wire tie.
6

Cable A
2

Cable B
6

1
CXO5841A

Align the Cable B connector with the right connector. Gently insert
the cable connector into module connector. Tighten both cable
connector thumb screws to fully seat the connector.
Install a wire tie through the holes on the cable support bracket and
around the cable. Tighten the wire tie.
Cable B

CXO5855A

Align the Cable B connector with the left connector on the other I/O
module. Gently insert the cable connector into module connector.
Tighten both cable connector thumb screws to fully seat the
connector.

5–14 UltraSCSI RAID Enclosure

Single-Ended I/O Modules

Table 5–6 Installing Three Enclosure System Cables (Continued)
9.

Install a wire tie through the holes on the cable support bracket and
around the cable. Tighten the wire tie.

10. Align the I/O module with the Port 1 backplane connector in the
second expansion enclosure shroud. Gently insert the module and
fully seat it. Use a screwdriver to tighten the spring-loaded mounting
screws.
11. Repeat steps 1 through 10 for the remaining SCSI buses.
12. Turn the subsystem on (see Table 5–7) and verify that it is
functioning properly.

Table 5–7 Turning On the UltraSCSI Subsystem
1.

Restore power to each enclosure by turning ON the ac power
controllers.

Connect a maintenance terminal to the array controller.

On controller “A”, press and hold the reset switch for at least 3
seconds.

On controller “B”, press and hold the reset switch for at least 3
seconds.

Other controller
This controller

CXO5716A

Verify that the other array controller is functioning by entering the
command—show other controller

Verify that this array controller is functioning by entering the
command—show this controller

UltraSCSI RAID Enclosure 5–15

Single-Ended I/O Modules

Cabling a Two–Enclosure Subsystem
____________________ Caution ____________________
Not all array controllers support an UltraSCSI RAID subsystem
with more than one enclosure. Read the array controller
documentation to ensure the controller supports expanded
configurations.
________________________________________________
Complete the procedures in Table 5–8 to connect the master enclosure to
one expansion enclosure. Perform this procedure for the I/O modules on
each SCSI bus starting with SCSI bus 1. Each SCSI bus requires one
BN37A cable for a total of 6 cables.
____________________ Caution ____________________
Overtightening the I/O module spring-loaded mounting screws
can damage the threads.
________________________________________________
Table 5–8 Installing Two Enclosure Subsystem Cables
1.

Shut down the array controller (see Table 5–5).
Use a screwdriver to loosen the two, spring-loaded mounting screws
on the I/O module.

Grasp the module by the cable support bracket and pull it directly to
the rear and remove it from the enclosure shroud.

CXO5816A

Repeat Steps 1 and 2 for all the I/O modules.

5–16 UltraSCSI RAID Enclosure

Single-Ended I/O Modules

Table 5–8 Installing Two Enclosure System Cables (Continued)
4.

On the first (master) I/O module, align the Cable A connector with
the left connector.
Cable A

CXO5854A

Align the module with the Port 1 backplane connector in the master
enclosure shroud. Gently insert the module and fully seat it. Use a
screwdriver to tighten the spring-loaded mounting screws.

Cable A
6

1
CXO5840A

Install a wire tie through the holes on the cable support bracket and
around the cable. Tighten the wire tie.

UltraSCSI RAID Enclosure 5–17

Single-Ended I/O Modules

Table 5–8 Installing Two Enclosure System Cables (Continued)
7.

CXO5855A

Install a wire tie through the holes on the cable support bracket and
around the cable. Tighten the wire tie.

5–18 UltraSCSI RAID Enclosure

Single-Ended I/O Modules

Replacing an I/O Module
Complete the procedure in Table 5–9 to remove I/O modules. Complete the
procedure in Table 5–10 to install I/O modules when assembling an
enclosure or replacing an individual module.
___________________ Caution _____________________
To prevent interrupting a data transfer or losing data, shut down
the subsystem before removing an I/O module.
________________________________________________
Table 5–9 Removing an I/O Module
1.

Shut down the array controller (see Table 5–10).
Use a screwdriver to loosen the two, spring-loaded mounting screws
on the I/O module.

Grasp the module by the cable support bracket and pull it directly to
the rear and remove it from the enclosure shroud.

CXO5940A

Cut the wire tie on the left cable. Loosen the thumb screws and
remove the cable.

Label the cable connector.

Cut the wire tie on the right cable. Loosen the thumb screws and
remove the cable.

Label the cable connector.

___________________ Caution _____________________
Overtightening the I/O module spring-loaded mounting screws
can damage the threads.
________________________________________________

UltraSCSI RAID Enclosure 5–19

Single-Ended I/O Modules

Table 5–10 Installing an I/O Module
1.

Remove the I/O module from the shipping container and verify that
it is a model DS–BA35X–MN.

Align the left cable with the I/O module connector.

Gently insert the cable connector into module connector. Tighten
both cable connector thumb screws to fully seat the connector.

CXO5940A

Install a wire tie through the holes on the cable support bracket and
around the cable. Tighten the wire tie.

Align the right cable with the I/O module connector.

Gently insert the cable connector into module connector. Tighten
both cable connector thumb screws to fully seat the connector.

Install a wire tie through the holes on the cable support bracket and
around the cable. Tighten the wire tie.

Align the I/O module with the backplane connector in the enclosure
shroud. Gently insert the module and fully seat it. Use a screwdriver
to tighten the spring-loaded mounting screws.

Turn on the subsystem and verify that it is operating properly.

5–20 UltraSCSI RAID Enclosure

Single-Ended I/O Modules

Replacing a Cable
___________________ Caution _____________________
Not all array controllers support an UltraSCSI RAID subsystem
with more than one enclosure. Read the array controller
documentation to ensure the controller supports expanded
configurations.
________________________________________________
Complete the procedure in Table 5–11 to remove expansion cable.
Complete the procedure in Table 5–12 to install cables when assembling an
enclosure or replacing an individual cable.
___________________ Caution _____________________
To prevent interrupting a data transfer or losing data, shut down
the subsystem before removing an I/O module.
________________________________________________

UltraSCSI RAID Enclosure 5–21

Single-Ended I/O Modules

Table 5–11 Removing an Expansion Cable
1.

Shut down the array controller (Table 5–5).
Use a screwdriver to loosen the two, spring-loaded mounting screws
on the I/O module.

Grasp the module by the cable support bracket and pull it directly to
the rear and remove it from the enclosure shroud.

Repeat Steps 1 and 2 for the other I/O module.

Cut the wire tie on the left cable. Loosen the thumb screws and
remove the cable.

CXO5940A

Label the cable connector.

Cut the wire tie on the right cable. Loosen the thumb screws and
remove the cable.

Label the cable connector.

____________________ Caution ____________________
Overtightening the I/O module spring-loaded mounting screws
can damage the threads.
________________________________________________

5–22 UltraSCSI RAID Enclosure

Single-Ended I/O Modules

Table 5–12 Installing an Expansion Cable
1.

Remove the expansion cable from the shipping container and verify
that it is proper type and length.

Align the left cable with the I/O module connector.

Gently insert the cable connector into module connector. Tighten
both cable connector thumb screws to fully seat the connector.

CXO5940A

Install a wire tie through the holes on the cable support bracket and
around the cable. Tighten the wire tie.

Align the right cable with the I/O module connector.

Gently insert the cable connector into module connector. Tighten
both cable connector thumb screws to fully seat the connector.

Install a wire tie through the holes on the cable support bracket and
around the cable. Tighten the wire tie.

Align the I/O module with the backplane connector in the enclosure
shroud. Gently insert the module and fully seat it. Use a screwdriver
to tighten the spring-loaded mounting screws.

Turn on the subsystem and verify that it is operating properly.

UltraSCSI RAID Enclosure 5–23

SES Template Word 7 Blank Page Fix by Peter LaQuerre

6
Power Distribution
This chapter describes the UltraSCSI RAID enclosure power distribution to
include the following:
•

The enclosure power system and components (see Figure 6–1)

•

Power distribution configurations (standard, redundant, optimum)

•

Configuring the power distribution

•

Error detection and reporting

•

Replacement procedures

Figure 6–1 Enclosure Power System

CXO5800A

UltraSCSI RAID Enclosure 6–1

Power Distribution

______________________Note _____________________
Proper operation of the controller cache modules requires
external cache batteries (ECBs). The array controller
documentation discusses how to use the ECBs.
________________________________________________

Power System Overview
In any RAID subsystem a consideration is the elimination of single
points of failure. Designing systems with redundant power capabilities is
one way to accomplish this.
The following are the major components of the power system:
•

AC power sources

•

Power controllers

•

Power cords

•

Shelf power supplies
______________________Note _____________________
The power controller power cords are integral to the data center
cabinets. For the departmental server cabinets the user–supplied
power cords are country–specific.
The SBB shelf ac power cords are integral parts of the
UltraSCSI enclosures.
________________________________________________

Power Configurations
For all StorageWorks products with the capability of using redundant
power, the power configurations definitions are in the format n+x. In this
format, n is the minimum number of supplies required for operation, and x
is the number of redundant supplies. The UltraSCSI enclosures require a
minimum of four (n) supplies.
Standard (n+1)
This configuration has one redundant power supply for a total of five power
supplies. A single power controller distributes ac power to the five supplies
on power bus A. This configuration requires only one ac power source.

6–2 UltraSCSI RAID Enclosure

Power Distribution

n+4 (Redundant)
This configuration has four redundant power supplies for a total of eight
power supplies. Two power controllers distribute ac power to four supplies
on power bus A and power bus B. This configuration requires only one ac
power source.
n+4 (Optimum)
This configuration has four redundant power supplies for a total of eight
power supplies. Two power controllers distribute ac power to four supplies
on power bus A and power bus B. This configuration requires two ac power
sources.

AC Power Source
The power controller requires one of the following ac power sources:
100–120 V ac, 60 Hz, single-phase, 12A.
or
220–240 V ac, 50 Hz, single-phase, 6A.
The optimum power configuration requires two separate ac power sources;
one for each power controller. The ac power sources cannot be on the same
distribution leg, use the same circuit breaker, nor the same ac wall
receptacle. They must have common ground.

UltraSCSI RAID Enclosure 6–3

Power Distribution

AC Input Power Controller
The ac power distribution is through the power controller (see Figure 6–2)
to the shelf power supplies. The ON–OFF switch on each power controller
controls the ac distribution to the associated power bus (A or B). These
power controllers are completely interchangeable and there are no physical
or electrical differences between them. These units do not have any error
indicators nor do they generate any error signals. In a standard or redundant
power supply configuration without an optional second power controller, a
power controller failure disables the enclosure.
Figure 6–2 AC Power Input Controller

AC power
switch

AC receptacle

CXO5488A

____________________ Caution ____________________
The only compatible power controller is the model
DS–BA35X–HE.
You cannot use the model BA35X–HE ac power controller in an
UltraSCSI RAID enclosure.
________________________________________________
The ON–OFF switch on each power controller controls the ac distribution to
the shelf power supplies on the same power bus (A or B). These power
controllers are completely interchangeable and there are no physical or
electrical differences between them. These units do not have any error
indicators nor do they generate error signals. A power controller failure can
disable the enclosure.

6–4 UltraSCSI RAID Enclosure

Power Distribution

Shelf Power Supplies
___________________ Caution ____________________
The UltraSCSI RAID enclosure requires shelf power supplies
rated for at least 180 W, such as the model DS–BA35X–HH
shelf power supplies. Other supplies, such as the 150 W power
supply, model BA35X–HF, can not be used.
________________________________________________
The shelf power supply converts the ac voltage to +5 V dc and +12 V dc
and distributes these voltages throughout the RAID enclosure.
•

The maximum capacity of the UltraSCSI RAID enclosure is eight
power supplies and has four redundant power supplies.

•

The standard power supply configuration has one redundant supply.

Figure 6–3 Shelf Power Supply

Shelf
status LED
(Green)
Power supply
status LED
(Green)

CXO-4787A-MC

UltraSCSI RAID Enclosure 6–5

Power Distribution

AC Power Buses
AC power distribution to the UltraSCSI shelf power supplies is over two
buses–bus A and bus B (see Figure 6–4). Each bus has an ac power source,
a separate power controller, power supplies, and power cords.
Although bus A, the n+1 configuration, can operate the system, DIGITAL
recommends using both buses, the optimum power configuration (n+4) with
two ac power sources.
Power bus A uses black power cords. The grey power cords are for power
bus B.
•

AC power controller A controls the black power cords—positions 1A
through 5A

•

AC power controller B controls the grey power cords—positions 1B
through 4B

Figure 6–4 Enclosure AC Power Buses
Power
bus A

Power
bus B

5A
4A 19 20 21 22 23 24 4B

Shelf 4

3A 13 14 15 16 17 18 3B

Shelf 3

10 11 12 2B

Shelf 2

Shelf 1

PVA
EMU
Controller A
Controller B
Cache A
Cache B

CXO5808A

6–6 UltraSCSI RAID Enclosure

Power Distribution

Standard (n+1) Power Configuration
This power configuration distributes ac power over power bus A to five
power supplies located in positions 1A through 5A. Power bus A uses the
black power cords on the left side of the enclosure and on the upper right
corner (see Figure 6–5).
Figure 6–5 Standard Power Configuration

CXO5929A

The standard power configuration has the following components:
1 – ac power source.
5 – shelf power supplies (Locations 1A through 5A).
1 – ac power controller (Location A).
Any one of the following power related error conditions will cause the
UltraSCSI RAID enclosure to cease operation:
•

Loss of the ac power source

•

Failure of two shelf power supplies

•

Failure of the power controller

UltraSCSI RAID Enclosure 6–7

Power Distribution

Redundant (n+4) Power Supply Configurations
This power configuration distributes ac power over both the power buses (A
and B). See Figure 6–6. Each bus has four power supplies.
To implement this configuration from an n+1 configuration requires the
user to order the following additional components:
•

3 – power supplies (DS–BA35X–HH)

•

1 – ac power controller (DS–BA35X–HE)

Figure 6–6 Redundant Power Configuration

CXO5797A

DIGITAL recommends this power configuration for complete data
protection with maximum redundancy of all enclosure power system
components. Any one of the following multiple error conditions can
comprise data integrity before you can take corrective actions:
•

Loss of the ac power source

•

Failure of five shelf power supplies

•

Failure of both power controllers

Power controller A distributes the ac power through the four black cords at
the left end of the device shelves. Power controller B distributes the ac
power through the four grey cords at the right end of the device shelves.

6–8 UltraSCSI RAID Enclosure

Power Distribution

Optimum (n+4) Power Supply Configurations
The only difference between this configuration and the redundant (n+4)
configuration is the use of separate ac power sources.
To implement this configuration from a standard n+1 configuration requires
the user to order the following additional components:
•

3 – power supplies (DS–BA35X–HH)

•

1 – ac power controller (DS–BA35X–HE)

To implement this configuration from n+1 or an n+4 configuration requires
a second ac power source.
DIGITAL recommends this power configuration for complete data
protection with maximum redundancy of all enclosure power system
components. Any one of the following multiple error conditions can
comprise data integrity before you can take corrective actions:
•

Loss of the ac power sources

•

Failure of five shelf power supplies

•

Failure of both power controllers

UltraSCSI RAID Enclosure 6–9

Power Distribution

Power Supply Error Condition Reporting
Each shelf power supply has two green LEDs that display the power supply
status (see Figure 6–7). Table 6–1 describes the following:
•

The LED state

•

The status being reported

•

The recommended corrective action

Figure 6–7 Power Supply Status LEDs

POWER
STATUS LED
(GREEN)
POWER SUPPLY
STATUS LED
(GREEN)

CXO-4787A-MC

Table 6–1 Shelf Power Status LED Displays
If the LED
display is…
LED is ON.

the Blower and Power Supply status is

The power supply is functioning properly.

LED is OFF

1.
LED is FLASHING

6–10 UltraSCSI RAID Enclosure

There is no ac power
Check ac power source.
The shelf power supply has failed.
Replace the shelf power supply

Power Distribution

Replacing a Power Supply
___________________ Caution _____________________
To protect this sensitive electronic device from electrostatic
discharge (ESD) use the following precautions—(1) Wear an
ESD wrist strap. (2) Do not touch the printed circuit board or
the backplane connector. (3) Do not lay the device on a work
surface but place it on an electrostatic mat. (4) Place the device
in an electrostatic bag for shipment.
________________________________________________
The basic procedure for removing and replacing shelf power supplies is the
same as for replacing disk drives. Normally you can replace one shelf power
supply without removing power from the enclosure.
There are two methods for replacing shelf power supplies—the hot swap
method and the cold swap method. Use the LEDs on the front of the SBB
that indicate the status, either operational or non-operational, to determine
the swap method to use.
•

Normally use the hot swap method

•

The cold swap method is normally used only during initial installation.
This requires removing the power from the UltraSCSI RAID enclosure
and all devices are inactive.

Complete the procedures in Table 6–2 and Table 6–3 to replace a shelf
power supply:
___________________ Caution ____________________
To prevent ESD (electrostatic discharge) damage to an SBB, do
not touch the SBB connector.
________________________________________________

UltraSCSI RAID Enclosure 6–11

Power Distribution

Table 6–2 Removing a Power Supply
1.

To perform a hot swap go to Step 3.

To perform a cold swap, turn off the ac power controller.

Disconnect the power cord from the front of the SBB.

Press the two mounting tabs together to release the power supply
from the shelf.

CXO-4314A-MC

Use both hands and pull the power supply out of the shelf.

Insert the power supply into an electrostatic shipping container.

Lay the supply on a flat surface.

Insert the shelf power supply into the guide slots and push it in to
fully seat it and the bezel mounting tabs engage the shelf.

Connect the power cord to the shelf power supply.

10. Both status LEDs should be ON.

6–12 UltraSCSI RAID Enclosure

Power Distribution

Table 6–3 Installing a Shelf Power Supply
1.

Remove the supply from the electrostatic shipping container and
verify that it is a 180 W power supply by checking the bezel label.

Lay the supply on a flat surface.

CXO-4314A-MC

Insert the shelf power supply into the guide slots and push it in to
fully seat it and the bezel mounting tabs engage the shelf.

Connect the power cord to the shelf power supply.

Both status LEDs should be ON.

Power Controller Error Condition Reporting
There are no power controller status indicators. A possible indication of a
power controller failure is that both status LEDs on all the associated shelf
power supplies are OFF. This could also indicate an ac power failure.

UltraSCSI RAID Enclosure 6–13

Power Distribution

Replacing a Power Controller
Complete the procedure in Table 6–4 to remove a power controller.
Complete the procedure in Table 6–5 when assembling the UltraSCSI
enclosure or replacing a single power controller.
___________________ WARNING __________________
Only qualified service personnel can replace an ac power
controller.
To prevent the possibility of injury or death as a result of
electrical shock—(1) Always disconnect the ac power cord
before removing a power controller. (2) Never touch the
backplane connector or circuit board. (3) Always install the
power controller before connecting the ac power cord.
________________________________________________

6–14 UltraSCSI RAID Enclosure

Power Distribution

Complete the procedure in Table 6–4 to remove an ac power controller.
Table 6–4 Removing an AC Input Power Controller
1.

Press O on the ON/OFF switch.

Disconnect the ac power cord.

Loosen the two retaining screws.

AC Power Entry
Controller A
Retaining
Screw (2X)
1
0

1
0

ON/OFF
Switch

AC Input
Power Cord
CXO-5186A-MC

Remove the power controller from the UltraSCSI RAID enclosure
and either place in on an electrostatic mat or place it in an
electrostatic bag.

UltraSCSI RAID Enclosure 6–15

Power Distribution

Table 6–5 Installing an AC Power Controller
1.

Remove the power controller from the shipping container and verify
that it is a model DS–BA35X–HE.

1
0

CXO5113A

Press O on the ON/OFF switch to turn the power controller OFF.

Align the first power controller with either slot A or slot B in the
lower left corner of the RAID enclosure.

AC Power Entry
Controller A
Retaining
Screw (2X)
1
0

1
0

ON/OFF
Switch

AC Input
Power Cord
CXO-5186A-MC

Push in on the power controller to fully seat it.

Tighten the two retaining screws.

Install the power cord from the ac power source to the ac power
controller.

Complete Steps 1 through 6 for the other power controller.

6–16 UltraSCSI RAID Enclosure

7
Storage Devices
This chapter describes the procedures for handling, addressing, identifying,
and replacing StorageWorks building block (SBB) disk drives in an
UltraSCSI RAID enclosure. Also described are error conditions and the
associated LED displays.
___________________ Caution _____________________
The DIGITAL UltraSCSI RAID enclosure supports 3.5-inch
disk drive SBBs. This enclosure does not support tape drives,
solid state disks, optical disk drives, CD–ROMs, or 5.25-inch
devices.
For a list of supported devices refer to the operating
system-specific release notes.
________________________________________________

UltraSCSI RAID Enclosure 7–1

Storage Devices

Handling an SBB
Figure 7–1 defines the proper methods for handling an SBB to prevent
damage.
Figure 7–1 SBB Handling Rules

Set the SBB on its side.

Do NOT set the SBB on its edge.

Set the SBBs side by side.

Do NOT stack SBBs.

Set the SBB down gently.

Do NOT drop the SBB.

Push the SBB into the shelf
gently, but firmly.

Do NOT force the SBB
into the shelf.
CXO5187B

7–2 UltraSCSI RAID Enclosure

Storage Devices

SBB Device Address
Determining the SBB device address is a function of the following:
•

The PVA–determined enclosure address (0, 2, or 3)

•

The SBB enclosure shelf location

SBB Status Reporting
StorageWorks shelves monitor the status of the storage SBBs. When a fault
occurs, the fault and the SBB device address (SCSI target ID) are reported
to the array controller or host for processing The SBB LEDs define the
status of the individual SBBs.
Each storage SBB has two LED indicators (see Figure 7–2) that display the
SBBs status. These LEDs have three states: on, off, and flashing.
Figure 7–2 SBB Status LEDs

Device
activity
(Green)
Device
fault
(Amber)

CXO-4652A-MC

•

The green LED is the device activity LED and is on or flashing when
the SBB is active.
___________________ Caution ____________________
Removing a storage SBB when the upper LED is on or flashing
can comprise data integrity.
________________________________________________

UltraSCSI RAID Enclosure 7–3

Storage Devices

•

The amber LED is the storage SBB fault status LED and indicates an
error condition when it is either on or flashing. The SCSI bus controller
controls this LED.

See Table 7–1 for definitions of the LED displays.
Table 7–1 SBB Status LED Displays
When the
LED display
is…
LED is ON.

the SBB Status is

The SBB is operating normally.

LED is OFF
LED is FLASHING

The SBB is operating normally.
The SBB is inactive, and there is no fault.

The SBB is probably not responding to control signals.
DIGITAL recommends that you replace the SBB.
The SBB is active and is spinning down because of the
fault.
DIGITAL recommends that you replace the SBB after
the device has spun down.
In response to a fault bus message, the array controller
is spinning down the device.
DIGITAL recommends that you replace the SBB after
the device has spun down.
The SBB is inactive and spun down.
You can replace the SBB.

7–4 UltraSCSI RAID Enclosure

Storage Devices

Identifying a Storage Device
To determine the model number of a device see the regulatory label (see
Figure 7–3) on the side of the SBB or the SBB identification label (see
Figure 7–4) on the bezel.
Figure 7–3 Typical SBB Regulatory Label

CXO5916A

The SBB bezel label includes the following device information:
•

Device type

•

SCSI bus type

•

User-defined information, such as:
 LUN # (logical unit number)
 ID # (device ID)
 CH # (channel number)

UltraSCSI RAID Enclosure 7–5

Storage Devices

Figure 7–4 Typical SBB Bezel Label
1
2

DS-RZ1CB-VW
4.3 GB

LUN #

ID #

CH #

40
F20
W
6

W
7
CXO5917A

1.
2.
3.
4.
5.
6.

The device model number.
The device storage capacity.
The user-assigned SCSI logical unit number (LUN).
The user-assigned SCSI identification number (target ID).
The user-assigned array controller channel number, that is the array
controller port or SCSI bus.
The SCSI bus device width where–
• N–an 8-bit device
• W–a 16-bit device
The StorageWorks shelf type (Wide or Narrow) in which you can
install the device where–
• N—the device is 8-bit shelf compatible.
W—the device is 16-bit shelf compatible.
• N/W—the device is compatible with either an 8- or 16-bit
shelf.
The bus speed expressed in megabits (Mb) per second where–
• S—Slow device. For example:
S5 = 5 Mb/s
• F—Fast device. For example:
F10 = 10 Mb/s
F20 = 20 Mb/s
The rate at which a 16-bit device can transfer data in megabytes
(MB) per second.

7–6 UltraSCSI RAID Enclosure

Storage Devices

Guidelines for Replacing SBBs
This section describes the items to consider when replacing SBBs.

Prerequisites for Replacing an SBB
Replacing an SBB is a relatively simple procedure. However, there are
several things you must consider.
When an array controller initializes a device, it establishes the device’s
physical location, the device address, and the logical unit number (LUN).
Physically moving the device, changing the bus, or changing the device
address will cause the bus to become erratic.
You can use the SBB identification label to identify the device model,
logical unit number (LUN), device address, array controller bus, and other
device specific characteristics.
___________________ Caution _____________________
To protect this sensitive electronic device from electrostatic
discharge (ESD) use the following precautions—(1) Wear an
ESD wrist strap. (2) Do not touch the printed circuit board or
the backplane connector. (3) Do not lay the device on a work
surface but place it on an electrostatic mat. (4) Place the device
in an electrostatic bag for shipment.
________________________________________________

SBB Replacement Methods
There are three methods for replacing StorageWorks storage SBBs: hot
swap, warm swap, and cold swap. You must determine the appropriate
replacement method based on the capabilities of the array controller before
replacing a device.
___________________ Caution _____________________
The methods for replacing DIGITAL array controllers and cache
modules are device dependent. Refer to the array user’s guide or
release notes for detailed instructions.
________________________________________________
Hot Swap
When you perform a hot swap, power and data are present on the SBB
enclosure connector.

UltraSCSI RAID Enclosure 7–7

Storage Devices

____________________ Caution ____________________
Although the HSZ70-series controllers support hot swap, other
controllers do not. If you are not positive that your SCSI
controller supports hot swap, DIGITAL recommends using
warm swap to protect the integrity of your data.
Read the array controller documentation to determine which
array controller-supported swap method to use.
________________________________________________
You can use hot swap to remove and replace SBBs from a system that is on
line and active.
Warm Swap
When you perform a warm swap, power is present on the SBB enclosure
connector and there is no data on the bus. Before you perform a warm swap
you must quiesce the bus at the array controller and observe the amber
status LED on the SBB and ensure that it is not flashing.
____________________ Caution ____________________
You can perform a warm swap only when the green device
activity LED is OFF.
________________________________________________

Cold Swap
When you perform a cold swap, neither power nor data is present on the
SBB enclosure connector. This requires turning OFF the enclosure power in
all the UltraSCSI RAID subsystem enclosures.

7–8 UltraSCSI RAID Enclosure

Storage Devices

The SBB Connector
The StorageWorks SBB connectors ensure that the SBBs will operate
reliably even when replaced many times.
The SBB has a 96-pin receptacle DIN connector that provides positive
mating with the SBB enclosure plug connectors. The connector design
ensures that:
1.

DC power is present until after the SCSI bus connection is broken.

DC power is present before the SCSI bus connection is made.

This feature protects the integrity of the SCSI data bus and avoids
introducing noise on the bus that could either distort data or cause the bus to
“hang.”
The SBB connector is a simple, highly reliable mechanism that can support
200 SBB replacement cycles. A replacement cycle consists of removing and
replacing an SBB. Over the active product life of 5 years, this is the
equivalent of 40 replacement cycles per year, or approximately 1 cycle
every 9 days. The replacement cycle limit applies equally to enclosure
connectors and device connectors.
Replacing the SBB more often than the recommended cycle, the gold
contact coating will wear away and destroy the integrity of the connection.
This product does not support environments that require a greater number of
replacement cycles and this is considered improper treatment or use
(paragraph 9.4b of U.S. Standard Terms and Conditions). Products or
connectors damaged because of a higher number of replacement cycles are
not eligible for return under warranty and standard service plans. DIGITAL
Equipment Corporation markets a specific family of removable storage
elements for higher replacement cycle environments. Contact your
DIGITAL Account Representative for more information.

UltraSCSI RAID Enclosure 7–9

Storage Devices

Replacing an SBB
Complete the procedure in Table 7–2 to remove an SBB. When initially
installing SBBs in an enclosure or installing a single SBB, complete the
procedure in Table 7–3.
Table 7–2 Removing an SBB
1.

To perform a hot swap go to Step 4.

To perform a warm swap, quiesce the SCSI bus.

To perform a cold swap, turn off the ac power controller.

Press the mounting tabs together to release the SBB.

Use both hands and pull the defective SBB out of the shelf.

CXO-4314A-MC

Insert the SBB into an electrostatic shipping container.

7–10 UltraSCSI RAID Enclosure

Storage Devices

Table 7–3 Installing an SBB
1.

Remove the SBB from the shipping container and ensure it is the
correct model.

CXO-4562A-MC

When assembling an UltraSCSI enclosure go to Step 3.
To install a single SBB, insert each SBB into the guide slots and
push it in until it seats fully and the mounting tabs engage the shelf.

CXO-4314A-MC

After installing the SBB, go to Step 7.

UltraSCSI RAID Enclosure 7–11

Storage Devices

Table 7–3 Installing an SBB (Continued)
3.

When assembling an UltraSCSI enclosure, install all the devices in
starting in the lower left corner (shelf 1, SCSI bus 1—
devices 1 through 6).
Power
bus A

Power
bus B

4A 19 20 21 22 23 24 4B

Shelf 4

3A 13 14 15 16 17 18 3B

Shelf 3

10 11 12 2B

Shelf 2

Shelf 1

PVA
EMU
Controller A
Controller B
Cache A
Cache B

CXO5811A

Starting at the left end, install all the devices in shelf 2
(devices 7 through 12).

Starting at the left end, install all the devices in shelf 3
(devices 13 through 18).

Starting at the left end, install all the devices in shelf 4
(devices 19 through 24).

When the SCSI bus is active and the SBB has power, the green
device activity LED is either ON, FLASHING, or OFF. The amber
device fault LED is OFF.

7–12 UltraSCSI RAID Enclosure

8
Enclosure Blowers
Ensuring proper UltraSCSI RAID enclosure operation requires establishing
and maintaining the proper operating environment. Meeting the temperature
and humidity ranges specified in Appendix A, “UltraSCSI Enclosure
Specifications,” involves using air conditioning to establish and maintain
the proper external, that is the ambient, environment. Failure to achieve
these goals could cause components to malfunction thereby causing the
comprising data integrity.
The eight blowers on the rear of the enclosure (see Figure 8–1) are an
integral part of the enclosure and ensure that the components remain cool.
These blowers are arranged in two banks of four blowers each. Air flow
provided by these blowers is sufficient to ensure proper operation of the
UltraSCSI subsystem.

UltraSCSI RAID Enclosure 8–1

Enclosure Blowers

Figure 8–1 Enclosure Blower Assemblies Locations

BANK 2
Blower 5

BANK 1
Blower 1

Blower 6
Blower 2

Blower 7

Blower 3

Blower 8
Blower 4

CXO-5494A-MC

The temperature sensors in the enclosure (see Chapter 3, “Environmental
Monitoring Unit”) detect overtemperature conditions or blower
malfunctions and alert the user to the problem. Simultaneously, the EMU
causes all the operational blowers to operate at high speed thereby
increasing air flow through the enclosure to increase cooling.
•

When the overtemperature condition is caused either by the intake
temperature or the exhaust temperatures (backplane) being too high, the
EMU initiates routines that can cause a power shut down to occur after
8 minutes.

•

Removing a blower significantly changes the air flow pattern within the
enclosure. The EMU initiates a routine that causes a power shut down
to occur after 8 minutes.

•

When there are two or more non-operating blowers (that is, not
operating or rotating too slowly) in the same blower bank the EMU
initiates a routine that causes a power shut down to occur after
8 minutes.

•

When the error condition is caused by no more than one defective
blower in a blower bank the EMU does not initiate a power shut down.

8–2 UltraSCSI RAID Enclosure

Enclosure Blowers

Function and Operation
Cooling the components is accomplished by pulling in air through the front
of each component, over the internal circuitry, through the backplane, and
exhausting it out the rear of the enclosure. The +12 V dc for blower
operation is available on each of the backplane blower connectors. The
blower status and speed control signals are also on these connectors and are
routed to the EMU and the PVA. The blower guide pin ensures you can
align the connectors when installing a blower. The combination of the
connectors and the blower mounting tabs provide positive mating of the
blower with blower plenum.
When an error condition involving the blowers, the intake temperature, or
the exhaust temperature exists, the EMU can cause all blowers to switch to
high speed to increase air flow through the enclosure. The conditions that
can cause this change in blower speed include:
•

Removing a blower

•

A blower operating too slowly

•

A stalled blower
___________________ Caution ____________________
The only StorageWorks dual speed blower that is compatible
with the UltraSCSI RAID enclosures is the model DS–BA35X–
MK. You cannot use the BA35X–MD dual-speed blower as a
replacement.
________________________________________________

UltraSCSI RAID Enclosure 8–3

Enclosure Blowers

Error Condition Reporting
The EMU LEDs display both blower and overtemperature error conditions.
See Table 3–6 for the blower error conditions and the recommended
corrective action.

Replacing a Blower
When there is a malfunctioning blower the other blowers operating at high
speed increases air flow through the components enough to permit
continued operation without corrupting or losing data. However, DIGITAL
recommends that you replace a defective blower immediately. If you
remove a blower and do not replace it within 8 minutes, the EMU can
implement the standby power mode, thereby protecting the components.
Complete the procedures in Table 8–1 and Table 8–2 to replace a blower.
____________________ Caution ___________________
Operating an UltraSCSI enclosure with a blower removed
significantly changes the air flow pattern and reduces air flow
through the components, If you remove a blower and do not
replace it within 8 minutes, the EMU will automatically turn off
the dc power distribution.
________________________________________________

8–4 UltraSCSI RAID Enclosure

Enclosure Blowers

Table 8–1 Removing a Blower
1.

Use both hands to firmly press the upper and lower blower mounting
tabs together to release the blower.

Connector
Guide

Upper
mounting
tab

Lower
mounting
tab (not shown)

CXO5753A

Pull the defective blower straight out.

Insert the blower into an electrostatic shipping container.

UltraSCSI RAID Enclosure 8–5

Enclosure Blowers

Table 8–2 Installing a Blower Assembly
1.

Remove the blower from the electrostatic shipping container and
verify that it is a model DS–BA35X–MK.

Orient the replacement blower so that the connector and guide pin
align with the backplane blower connector.

Connector
Guide

Upper
mounting
tab

Lower
mounting
tab (not shown)

CXO5753A

Push the blower straight in, until the upper and lower mounting tabs
snap into place.

The blower should start operating when shelf power is present.

8–6 UltraSCSI RAID Enclosure

A
UltraSCSI Enclosure
Specifications
This appendix defines the physical, electrical, and environmental
specifications for the DIGITAL StorageWorks UltraSCSI enclosure with
24 disk drives (SBBs) and the following major electronic components:
10

9
8x

2 8x

3 6x

7 2x

5 2x

6 2x
CXO5555A

1.
2.
3.
4.
5.

DS–BA370 Enclosure
Blowers (8 each)
I/O Modules (6 each)
PVA (1 each)
Power Controller (2 each)

6. Cache Module (2 each)
7. Controller (2 each)
8. EMU (1 each)
9. 180 W Power Supply (8 each)
10. External Cache Battery

UltraSCSI RAID Enclosure A–1

UltraSCSI Enclosure Specifications

______________________Note _____________________
The operating and servicing physical specifications as well as
the electrical specifications of the UltraSCSI RAID enclosure
are cabinet and configuration specific.
________________________________________________

Physical and Electrical Specifications
The following specifications apply to a single, Ultra SCSI enclosure with all
the components installed:
Shipping Dimensions

Height
Width
Depth
Weight

Installed Dimensions

1156 mm
(45.5 in)
978 mm
(38.5 in)
737 mm
(29 in)
135 kg
(298 lb)

Height
Width
Depth
Weight

749 mm
(29.5 in)
435 mm
(17.125 in)
432 mm
(17 in)
102 kg
(225 lb)

Heat Dissipation

3070 BTUs/hr
Power
CXO5929A

110–240 V ac,
50-/60-Hz, Single
Phase, 12 A/6 A

A–2 UltraSCSI RAID Enclosure

UltraSCSI Enclosure Specifications

Operating Environments
DIGITAL recommends maintaining the following environments to ensure
proper operation of this product.
Condition

Specification
Optimum Operating Environment
(Suggested for optimum operation)

Temperature

18°C to +24°C (+64°F to +75°F) with an
average rate of change of
3°C/hour maximum and a step change of
3°C or less

Relative humidity

40% to 60% (noncondensing) with a
step change of 10% or less (noncondensing)

Altitude

Up to 2400 m (8000 ft)

Air quality

Not to exceed a maximum of 500,000 particles,
0.5 micron or larger, per cubic foot of air.

Nominal airflow

50 cubic ft/minute

Heat Dissipation

3070 BTUs/hr
Minimum Operating Environment
(Required for proper operation)

Temperature

+10°C to +40°C (+50°F to +104°F)
Reduce rating by 1.8°C for each 1000 m
altitude (1.0°F for each 1000 ft altitude)

Relative humidity

10 to 85% at maximum wet bulb temperature of
+32°C (+90°F) and a minimum dew point
of +2°C (+36°F)

Altitude

Up to 2400 m (8000 ft)

Air quality

Not to exceed a maximum of 500,000 particles,
0.5 micron or larger, per cubic foot of air.

Nominal airflow

40 cubic ft/minute

Heat Dissipation

3070 BTUs/hr

Non-Operating Operating Environment
(Shipping or short term storage)

Temperature

–40°C to +66°C (–40°F to +150°F)

Relative humidity

10% to 80% noncondensing

Altitude

4900 m (16,000 ft)

UltraSCSI RAID Enclosure A–3

UltraSCSI Enclosure Specifications

SBB Thermal Stabilization
For proper operation upon initial power application, the DIGITAL SBB
storage device temperature should be within the range of 18-29°C
(65-85°F).
____________________ Caution ____________________
Always stabilize disk drives in the operating environment before
installation or operation. Otherwise, applying power can damage
the media or associated.
________________________________________________

Condition

Then You Must …

When there is condensation on the outside of
the SBB

Stabilize the device and the SBB in the
operating environment for 6 hours or until the
condensation is no longer visible, whichever is
longer. Do not install a storage device until it
stabilizes.

When there is no condensation on the outside
of the SBB

Thermally stabilize the device for the amount
of time specified

Storage Temperature Range

°C

°F

Stabilize for

°C

°F

Stabilize for

60 to 66

140 to 151

3 hours

0 to 9

32 to 48

1 hour

50 to 59

122 to 138

2 hours

-10 to -1

14 to 30

2 hours

40 to 49

104 to 120

1 hour

-20 to -11

-4 to 12

3 hours

30 to 39

86 to 102

30 minutes

-30 to -21

-22 to -6

4 hours

18 to 29

64 to 84

None

-40 to -31

-40 to -24

5 hours

10 to 17

50 to 63

30 minutes

A–4 UltraSCSI RAID Enclosure

B
Assembling an UltraSCSI
RAID Subsystem
Assembling an UltraSCSI RAID subsystem requires sequentially installing
the components in a DS–BA370–series rack-mountable enclosure. You can
mount these enclosures in either a departmental cabinet, a “pedestal,” or a
data center cabinet (SW600–series), and then testing the subsystem for
proper operation.

CXO5797A

__________________ WARNING ____________________
With all the components installed, a RAID enclosure with
the packing material weighs approximately 135 kgs (298 lbs).
To prevent personal injury always mount the enclosure in
the data center cabinet or departmental cabinet before
installing any components. The empty enclosure weighs
more than 102 kgs (225 lbs).
________________________________________________

UltraSCSI RAID Enclosure B–1

Assembling an UltraSCSI RAID Enclosure

Installation Sequence
The basic installation sequence is the same for all UltraSCSI RAID
subsystems, whether they use one, two, or three DS–BA370 enclosures. To
reduce the possibility of multiple, interacting problems the preferred
assembly sequence is as follows:
1.

Assemble and test the master enclosure.

Assemble the first expansion enclosure.

Connect the first expansion enclosure to the master enclosure and test
the subsystem operation.

Assemble the second expansion enclosure.

Connect the second expansion enclosure to the master enclosure and
test the subsystem operation.

The assembly procedures for an enclosure are almost identical to those
described elsewhere in this publication. Therefore, rather than repeating the
procedures, the following sections primarily address special assembly
considerations. The recommended sequence for assembling an UltraSCSI
RAID enclosure is as follows:
1.

Mount UltraSCSI RAID enclosure in the data center cabinet or the
departmental server cabinet.

Install the power system.

Install the EMU.

Install the PVA.

Install the disk drive SBBs.

Cable and install the I/O modules.

Install the array controllers and cache modules.

Install the ECBs.

Configure the subsystem as described in Chapter 2, “Configuring an
UltraSCSI RAID Subsystem.”

B–2 UltraSCSI RAID Enclosure

Assembling an UltraSCSI RAID Enclosure

Installing the Power System
The ac power controllers and shelf power supplies comprise the enclosure
power system.

CXO5800A

___________________ Caution ____________________
To prevent ESD (electrostatic discharge), do not touch the
connector.
________________________________________________
_____________________ Note ______________________
The ac power controller has no user serviceable components.
Should a power controller fail you must replace the entire
assembly.
________________________________________________
The sequence for installing the power system is as follows:
1.

Install the ac power controllers (Table 6–5).

Install the shelf power supplies (Table 6–3).

UltraSCSI RAID Enclosure B–3

Assembling an UltraSCSI RAID Enclosure

Installing the EMU
Each UltraSCSI enclosure requires an EMU for proper operation. In an
expansion configuration you must also connect the EMU—EMU
communications ports between the master EMU and all the expansion
EMUs. Complete the following procedure to install an EMU.
There are two steps to installing an EMU:
1.

Install the EMU in each enclosure (see Table 3–9).

When there are multiple EMUs, install the EMU-EMU bus cables listed
in Table 3–10.

Installing the PVA
Each UltraSCSI enclosure requires a PVA for proper operation.
Complete the procedure in Table 4–7 to install a PVA in each enclosure:

Installing the Disk Drives
Install the SBBs sequentially in the UltraSCSI enclosure using the
procedure in Table 7–3.
1.

Install six SBBs in shelf 1, starting with SCSI bus 1
(devices 0 through 6).

Install six SBBs in shelf 2, starting with SCSI bus 1
(devices 7 through 12).

Install six SBBs in shelf 3, starting with SCSI bus 1
(devices 13 through 18).

Install six SBBs in shelf 4, starting with SCSI bus 1
(devices 19 through 24).

B–4 UltraSCSI RAID Enclosure

Assembling an UltraSCSI RAID Enclosure

Installing the I/O Modules
The six single-ended I/O modules (DS–BA35X–MN) mount on the lower
rear of the enclosure.

2
4
6
5

3
Ports
CXO5805A

In an expanded subsystem, connect the cables to the I/O modules (see
Table 5–12) and then install the I/O modules in the enclosures (see
Table 5–10). For a single enclosure subsystem, install the I/O modules in
the enclosures (see Table 5–10).

Installing Expansion Cables
___________________ Caution _____________________
Not all array controllers support more than one enclosure. Read
the controller documentation to verify that it does support more
than one enclosure.
________________________________________________

The UltraSCSI bus expansion cables connect to the six single-ended I/O
modules (DS–BA35X–MN) mounted on the lower rear of the enclosure.
Complete the procedure in Table 5–12 to install the expansion cables.
___________________ Caution _____________________
Overtightening the I/O module spring-loaded mounting screws
can damage the threads
________________________________________________

UltraSCSI RAID Enclosure B–5

Assembling an UltraSCSI RAID Enclosure

Installing Controller “A”
The UltraSCSI master enclosure contains the array controllers and cache
modules. You cannot install the ECBs (external cache batteries) in the
enclosure. In a departmental cabinet, you install the ECBs in the top cover.
In a data center cabinet, you install the ECBs in a shelf mounted in the
cabinet.
____________________ Caution ____________________
You can install only one set of array controllers and cache
modules in an UltraSCSI RAID subsystem. By default, this
enclosure becomes the master enclosure and always has
address 0.
________________________________________________
For complete, detailed array controller, cache module, and ECB installation
procedures, to include cabling, refer to the array controller documentation.

CXO5798A

The following procedure describes the mechanical procedures for installing
an array controller and a cache module. You must configure the subsystem
using the procedures in the following publications:
•

The array controller documentation

•

The operating system-specific release notes

B–6 UltraSCSI RAID Enclosure

Assembling an UltraSCSI RAID Enclosure

Controller A Installation

Complete the sequential installation of the following UltraSCSI
enclosure components:
a) Power controllers and power supplies
b) EMU
c) PVA
d) Disk Drives
e)
f)

I/O Modules
UltraSCSI expansion cables

Align controller “A” with the top controller slot (device address 7).
Power
bus A

Power
bus B

4A 19 20 21 22 23 24 4B

Shelf 4

3A 13 14 15 16 17 18 3B

Shelf 3

10 11 12 2B

Shelf 2

Shelf 1

PVA
EMU
Controller A
Controller B
Cache A
Cache B

CXO5813A

UltraSCSI RAID Enclosure B–7

Assembling an UltraSCSI RAID Enclosure

Controller A Installation (Continued)

Insert the array controller into the slot and push it in until the
extractor latches engage the enclosure.

CXO5602A

Push in on the extractor latches to firmly seat the array controller.

Align controller “A” cache module with the cache module A slot in
the enclosure.

Insert the cache module into the slot and push it in until the extractor
latches engage the enclosure.

Push in on the extractor latches to firmly seat the cache module.

B–8 UltraSCSI RAID Enclosure

Assembling an UltraSCSI RAID Enclosure

Installing Controller “B”
The following procedure describes the mechanical procedures for installing
an array controller and a cache module. You must configure the subsystem
using the procedures in the following publications:
•

the array controller documentation

•

The operating system-specific release notes.
Controller B Installation

Complete the sequential installation of the following UltraSCSI
enclosure components:
a) Power controllers and power supplies
b) EMU
c) PVA
d) Disk Drives
e) I/O Modules
f) UltraSCSI expansion cables
g) Controller “B”

Remove the blank panels from the controller B and cache module B
positions.
Align controller “B” with the lower controller slot (device
address 6).
Power
bus A

Power
bus B

4A 19 20 21 22 23 24 4B

Shelf 4

3A 13 14 15 16 17 18 3B

Shelf 3

10 11 12 2B

Shelf 2

Shelf 1

PVA
EMU
Controller A
Controller B
Cache A
Cache B

CXO5812A

UltraSCSI RAID Enclosure B–9

Assembling an UltraSCSI RAID Enclosure

Controller B Installation (Continued)

Insert the array controller into the slot and push it in until the
extractor latches engage the enclosure.

CXO5603A

Push in on the extractor latches to firmly seat the array controller.

Align controller “A” cache module with the cache module A slot in
the enclosure.

Insert the cache module into the slot and push it in until the extractor
latches engage the enclosure.

Push in on the extractor latches to firmly seat the cache module.

Internal Cables
All internal cables are cabinet–specific. The cabinet user documentation
describes the cable routing, location and function. The cables involved may
include:
•

Controller–to–controller

•

Controller-to–host

•

ECB–to–cache module cables

For a detailed description of the cable connection procedures and cable
routing refer to following publications:
•

The array controller documentation.

•

DIGITAL StorageWorks UltraSCSI RAID Cabinet Subsystem
(SW600-Series) Installation and User’s Guide.

B–10 UltraSCSI RAID Enclosure

Glossary
ac distribution
The method of distributing ac power within a StorageWorks shelf,
enclosure, or cabinet.
ac power supply
See shelf power supply.
adapter
See SCSI signal bus converter.
ambient air temperature
The temperature of the air surrounding the cabinet, enclosure, shelf, or SBB
that dissipates the heat generated by the device. Also referred to as the
intake air temperature.
array controller
See controller.
backplane
The electronic printed circuit board mounted in the rear of the shelf. This
board contains the SBB, power supply, and terminator connectors.
blower assembly
An airflow device mounted in a StorageWorks shelf.

UltraSCSI RAID Enclosure Glossary–1

Glossary

bus expander
Devices that couple bus segments together without any impact on the SCSI
protocol, or the software. These devices include both single-ended to
differential and single-ended to single-ended bus extenders. The term
extender is a general term that includes “extender,” “repeater” and
“isolator.”
bus extender
See bus expander.
bus segment
A SCSI bus segment consists of all the conductors and connectors required
to attain signal line continuity between every driver, receiver, and two
terminators for each signal. It is not necessary that a SCSI bus segment
contain any initiators or targets, but it must have at least two devices
attached. (Drivers and receivers may be part of extenders as well as part
initiators and targets.)
Bus segments can be either single-ended (SE) or differential (DF). The
terminator properties determine the bus segment type.
____________________ Caution ____________________
The device transceiver type (single-ended or differential) must
match the bus segment type. Devices that do not meet this
condition cannot operate.
________________________________________________

The allowed length of a bus segment depends on the electrical loading,
transmission media type, and data transfer rate. In many cases, heavier
loading, smaller wires, and higher speeds demand shorter lengths.
Increasing the number of devices in a given length of the bus, by using
longer stubs, or higher capacitance devices produces loading.
bus segment types
The following are the SCSI bus segments types:
•

Single-ended (SE)

•

High voltage differential (HVD)

Glossary–2 UltraSCSI RAID Enclosure

Glossary

The terminator properties (single-ended or differential) determine the bus
segment type. Devices that do not have the same transceiver type as the
terminators cannot operate in the segment defined by the terminators.
cabinet
See data center cabinet and departmental server cabinet
cable connector
Any connector that is physically part of a cable assembly attached to
backplanes or other non–device connectors.
cache module
A fast storage buffer.
Callout n
A textual reference to a numbered callout in a figure.
carrier
See modular carrier.
CE–Mark
A European Economic Community (EEC) certification label that identifies
electronic devices authorized for sale within member nations.
CE–Mark Class A
Similar to, but more stringent than the FCC Class A certification, this
certification label appears on electronic devices that are for use in a
commercial environment. You can also use a CE–Mark certified device in
the United States.
CE–Mark Class B
Similar to, but more stringent than the FCC Class B certification, this
certification label appears on electronic devices that are for use in either a
home or a commercial environment. You can also use a CE–Mark certified
device in the United States.

UltraSCSI RAID Enclosure Glossary–3

Glossary

certified device
A storage device tested in a specific configuration and found to be in
compliance with either an FCC or a CE certification standard. DIGITAL
certifies these devices to operate in a specific shelf, enclosure, or cabinet.
channel
Another term for a SCSI bus.
CLI
Command line interpreter. The operator interface to HSx-series array
controller software.
cold swap
A method of device replacement that requires that power be removed from
one or more shelves in a cabinet thereby affecting other devices. Use this
method during initial installation or StorageWorks subsystem upgrades, or
when conditions preclude using either the "warm swap” or “hot swap”
method
See also warm swap and hot swap.
command line interpreter
See CLI.
controller
(1) A hardware–software device that manages communications on behalf of
host systems over the SCSI bus to devices. Controllers typically differ by
the type of interface to the host and provide functions beyond those the
devices support. (2) A standalone device that connects a host adapter to the
storage SCSI bus. This device provides RAID functionality, typically has
multiple SCSI bus ports, performs the lower layers of the SCSI protocol,
and normally operates in the initiator role.
Also referred to as array control or SCSI bus controller.
converter
See SCSI signal bus converter.

Glossary–4 UltraSCSI RAID Enclosure

Glossary

data center cabinet
The largest of the StorageWorks cabinet, such as the SW800-series that can
contain as many as 24 SBB shelves. These cabinets include either a 50 Hz
or 60 Hz cable distribution unit (CDU), internal ac power cords, and cooling
fans.
departmental server cabinet
The series of smaller StorageWorks cabinets for mounting shelves,
controllers, storage device, and power control devices to form subsystems.
device
The targets, initiators, hubs, converters, and bus expanders, and similar
device interconnected to form a SCSI bus. Connectors, expanders, and hubs
do not use a SCSI bus ID.
See also nodes.
device connector
Any connector physically part of a SCSI device.
differential SCSI bus
A bus in which the potential difference between two wires determines the
signal level.
disk
A storage device supporting random access to fixed size blocks of data.
disk array controller
See controller.
dual power configuration
See redundant power supply configuration.
dual redundant configuration
An array controller configuration consisting of controller “A” and controller
“B” mounted in the same controller shelf. When controller “A” fails,
controller “B” assumes control over the devices.

UltraSCSI RAID Enclosure Glossary–5

Glossary

dual bus
Configuring a single SBB shelf SCSI bus as two individual buses (a four
device bus and a three device bus) creates a bus known as a dual or split
bus.
ECB
External cache battery.
electromagnetic interference
See EMI.
electrostatic discharge
See ESD.
EMI
Electromagnetic interference is the impairment of a signal by an
electromagnetic disturbance.
EMU
Environmental Monitoring Unit. The device that monitors the status of the
UltraSCSI RAID enclosure to include power, intake air temperature, blower
status, and so forth, detects error and fault conditions, displays these
conditions, reports the conditions to the user and the array controller, and, in
some cases, implements corrective actions.
enclosure connector
Any connector that is physically part of an enclosure (for example, pedestal,
deskside enclosure, cabinet, and so forth).
end–bus position
See SCSI end–bus position.
Environmental Monitoring Unit
See EMU.
ESD
Electrostatic discharge is the discharge of a potentially harmful static
electric voltage as a result of improper grounding.

Glossary–6 UltraSCSI RAID Enclosure

Glossary

expansion enclosure
An UltraSCSI RAID enclosure connected to the master enclosure with
UltraSCSI bus cables. Each subsystem can have a maximum of two
expansion enclosures. Set the expansion PVA SCSI bus address switch to
either:
2–to establish SCSI bus device addresses 8, 9, 10, and 11.
3–to establish SCSI bus device addresses 12, 13, 14, and 15.
external cache battery
See ECB.
Fast 20
See UltraSCSI.
FCC
Federal Communications Commission is the federal agency responsible for
establishing standards and approving electronic devices within the United
States.
FCC Class A
This certification label appears on electronic devices for use only in a
commercial environment within the United States. A CE-Mark certified
device can be used in the United States in the same environment as the
equivalent FCC certification.
FCC Class B
This certification label appears on electronic for use in either a home or a
commercial environment within the United States. A CE–Mark certified
device can be used in the United States in the same environment as the
equivalent FCC certification.
Federal Communications Commission
See FCC.
filler panel
A panel used to cover open unused areas in cabinets or shelves for either
EMI suppression, air flow control, or cosmetic purposes.

UltraSCSI RAID Enclosure Glossary–7

Glossary

host
The primary or controlling computer (in a multiple computer network) to
which storage is attached.
host adapter
A device that connects the host system I/O bus (for example, a PCI bus) to
the storage SCSI bus. A host adapter performs the lower layers of the SCSI
protocol and normally operates in the initiator role.
host computer
See host.
host controller
A device that connects the host system I/O bus (for example, a PCI bus) to
the storage SCSI bus. A host controller provides RAID functionality,
typically has multiple SCSI bus ports, performs the lower layers of the SCSI
protocol, and normally operates in the initiator role.
host port adapter
A host controller device that adapts the host system I/O bus to the array
controller SCSI bus configuration.
hot swap
A method of device replacement whereby the complete system remains
on-line and active during device removal or insertion. The device being
removed or inserted is the only device that cannot perform operations
during this process.
See also cold swap and warm swap.
HSOF
Hierarchical Storage Operating Firmware. HS-family controller software
contained on a removable ROM card (PCMCIA).
I/O module
A SCSI enclosure or SBB shelf device that integrates a single-ended SCSI
bus with either an 8–bit single-ended, 16–bit single-ended, or 16–bit
differential SCSI bus. This module is also a SCSI bus extender,
See also shelf I/O Module.

Glossary–8 UltraSCSI RAID Enclosure

Glossary

initiator
A SCSI device (usually a host system) that requests another SCSI device (a
target) to complete an operation.
Input/Output module
See I/O module.
isolator
See bus extender.
Intake air temperature
The temperature of the air entering the cabinet, enclosure, shelf, or SBB.
Also referred to as the ambient temperature.
logical bus
A single-ended, physical bus connected to a differential physical bus by a
SCSI bus signal converter.
logical units
A group of devices addressable as a virtual unit.
maintenance terminal
The operator terminal used to identify an HS-family controller, to enable its
host paths, to define its subsystem configuration, and to check its status.
The HS-family maintenance terminal accepts any terminal conforming to
EIA–423. Use the maintenance terminal to configure a storage subsystem.
master enclosure
The UltraSCSI RAID enclosure that includes the HSZ-series controllers and
cache modules. There is only one master enclosure in each UltraSCSI RAID
subsystem. The SCSI bus address switch setting is always 0. Using address
0 automatically assigns SCSI bus device addresses 0, 1, 2, and 3 to the
devices.
MB/s
See MB/sec.

UltraSCSI RAID Enclosure Glossary–9

Glossary

MB/sec
The bus width (8- or 16-bit), the number of bytes per word (1 or 2,
respectively), and the bus clock frequency determines the transfer rate in
megabytes per second (MB/sec).
megabytes per second
See MB/sec.
modular carrier
The StorageWorks compatible plastic container in which storage devices or
power supplies are mounted to form SBBs. Modular carriers are available in
both 3.5-inch and 5.25-inch form-factors.
node
A SCSI bus target or initiator that uses a SCSI bus ID. For example, disk
drives, tape drives, array controllers, and adapters all have a SCSI bus ID
and are nodes. Hubs, expanders, and converters are devices and do not have
a SCSI bus ID.
An UltraSCSI bus can have a maximum of 16 nodes (SCSI bus addresses
0 through 15).
A narrow bus can have a maximum of eight nodes, SCSI bus addresses
0 through 7.
Overtemperature
A condition where a temperature is above a specified limit and can cause
equipment failure if not corrected.
pedestal
The common name for a deskside expansion unit. Also see departmental
server cabinet.
physical bus
Two SCSI terminators separated by cables, connectors, and backplane
circuitry.
port
(1) A logical route for data in and out of an array controller. A port can
contain one or more channels, all of which contain the same type data. (2)
The hardware and software that connects a host controller to a CI, SCSI, or
SDI bus.
Glossary–10 UltraSCSI RAID Enclosure

Glossary

power verification and addressing assembly
See PVA.
PVA
Power Verification and Addressing assembly. The module whose primary
functions are (1) allow the user to select the enclosure UltraSCSI bus ID,
(2) enable the user to place the subsystem in a standby power mode and
return it to an operational status. (3) in conjunction with the associated
EMU ensures that critical power functions are monitored.
qualified device
See supported device.
quiesce
To make a bus inactive or dormant. For example, you must quiesce SCSI
bus operations when warm swapping an SBB.
quiescent
A bus that is inactive, still, or dormant.
radio frequency interference
See RFI.
RAID
Redundant array of independent disks. A set of storage techniques devised
to increase the performance and availability of a storage subsystem.
redundant power supply configuration
A capability of StorageWorks cabinet and shelves to ensure there is no
single point of power failure. (1) For a cabinet two ac power sources and
two distribution units or power controllers distribute primary and redundant
ac power to shelf power supplies. (2) For a shelf, the primary and redundant
shelf SBB power supplies ensure the dc power is available even when there
is a failure of one supply, one ac source, or one distribution unit or power
controller.
repeater
See bus extender.

UltraSCSI RAID Enclosure Glossary–11

Glossary

RFI
Radio frequency interference. The impairment of a signal by an unwanted
radio signal or radio disturbance.
SBB
StorageWorks building block is basic building block of the product line.
Any device conforming to shelf mechanical and electrical standards
installed in either a 3.5-inch or 5.25-inch carrier is considered to be an SBB,
whether it be a storage device, a power supply, or other device.
SCSI
Small computer system interface. This ANSI interface defines the physical
and electrical parameters of a parallel I/O bus used to connect computers
and a maximum of seven devices.
SCSI bus signal converter
(1) A connecting device that permits the attachment of accessories or
provides the capability to mount or link units. (2) The device that connects
a differential SCSI bus to a single-ended SCSI bus. (3) The device that
connects a differential SCSI bus operating to a single-ended SCSI bus.
(4) The device that extends the length of a differential or single-ended
SCSI bus.
See also shelf I/O module.
SCSI busing connection
A connection on the SCSI bus between two terminators, such as the SBB
shelf SCSI input connector.
SCSI device
A host computer adapter, a peripheral array controller or an intelligent
peripheral that can be attached to the SCSI bus.
SCSI device–side device address
The 8-bit narrow (0 through 7) or 16-bit wide (0 through 15) device
addresses (target IDs) assigned to the SCSI controller and the devices it
controls.
See also SCSI host–side device address.

Glossary–12 UltraSCSI RAID Enclosure

Glossary

SCSI device ID
The bit-significant representation of the SCSI addressing referring to one of
the signal lines numbered 0 through 7 for an 8-bit bus or 0 through 15 for a
16-bit bus. Also known as “target ID”.
SCSI domain
A SCSI domain is a logical bus consisting of at least one bus segment, at
least one initiator, and at least one target. Domains with multiple bus
segments are enabled through the use of bus extenders. Domains are limited
by device addressability. Domains are limited to a maximum of 16 initiators
and targets without the use of LUN bridges.
SCSI host-side device address
The eight device addresses (target IDs) assigned to the host device and the
SCSI controllers and the devices it controls.
See also SCSI device-side device address.
SCSI ID
See SCSI device ID.
SCSI port
(1) Software. The channel that controls communications to and from a
specific SCSI bus in the system. (2) Hardware. The name of the logical
socket at the back of the system unit to which a SCSI device is connected.
shelf power supply
The power supply that provides +5 V dc and +12 V dc to the StorageWorks
shelves. These supplies can be either ac input (120 V ac) or dc (48 V dc).
single-ended SCSI bus
A bus in which the voltage of a single wire in relation to ground determines
each signal’s logic level.
single-power configuration
A power configuration in which there is only one ac power source and
CDU, PDU, or power controller to condition the input ac power.
Small Computer System Interface
See SCSI.

UltraSCSI RAID Enclosure Glossary–13

Glossary

spin-down
The process that begins when power is removed from a storage device and
data transfer halts, and ends when the device is stopped and can be moved.
In the case of disk drives, the heads are retracted and the media is stopped.
spin-up
The process that begins when power is applied to a storage device, and ends
when the device is determined to be operational and ready for data transfer
operations.
split bus
See dual bus.
STERMPOWER
Terminator power on a single-ended SCSI bus.
See TERMPOWER.
storage array
An integrated set of storage devices.
storage array subsystem
See storage subsystem.
storage sets
A grouping of disk drives that make up a new distinct container.
storage subsystem
The array controllers, storage devices, shelves, cables, and power supplies
that form a mass storage subsystem.
StorageWorks
The DIGITAL set of enclosure products that allows customers to design and
configure their storage subsystem. Components include power, packaging,
and interconnections in a StorageWorks shelf. SBBs and array controllers
are integrated therein to form storage subsystems. System-level enclosures
to house the shelves and standard mounting devices for SBBs are also
included.

Glossary–14 UltraSCSI RAID Enclosure

Glossary

StorageWorks building block
See SBB.
subsystem array strategy
A strategy, including packaging, devices, and array controllers, that
provides an integrated storage subsystem solution.
supported device
(1) A device that has been fully evaluated in an “approved” StorageWorks
configuration (that is, shelf, cabinet, power supply, cabling, and so forth)
and is in complete compliance with country-specific standards (for example,
FCC, CE-Mark, CSA, TÜV, VDE, and so forth) and with all DIGITAL
standards. (2) A device supported by an array controller or host operating
system.
target
A SCSI device that performs an operation requested by an initiator.
target ID
See SCSI device ID.
terminators
The interconnect components that form the ends of the transmission lines in
bus segments. A SCSI domain must have at least one segment and therefore
at least two terminators. The terminators ensure that inactive SCSI bus
signals are in a known state.
There are two basic types of terminators–active and passive.
•

Single-ended bus segments use active, linear terminators

•

Differential bus segments use a passive (linear totem pole) terminators
except for special cases where the electrical transmission lines are very
short and only one termination or pull–up is required.

terminator connector
Any connectors physically part of a terminator. It is not uncommon for
terminators to have both stub and bus–path connectors.

UltraSCSI RAID Enclosure Glossary–15

Glossary

TERMPOWER
The electrical current power required for SCSI bus terminators. This power
may be supplied by an external SCSI bus, the shelf power supply or an ac–
dc power converter.
topology
The physical arrangement and relationship of interconnected nodes and
SCSI buses in a network. A legal topology must satisfy all the requirements
of the associated SCSI bus (Fast 10, UltraSCSI, and so forth).
transmission medium
An electrical conductor has bus termination on each end and possibly stubs.
Common examples of media are cables, printed wiring boards, flex circuits,
and connectors that create electrical connections between various
combinations SCSI devices, bus extenders, and terminators.
UL
Underwriters Laboratories. An organization that tests and certifies electrical
devices.
UltraSCSI
An improvement in SCSI technology invented in 1993 by the Digital
Equipment Corporation StorageWorks Engineering Group. Subsequently
the ANSI SCSI standards committee issued standard X3T10 for UltraSCSI.
The UltraSCSI improvements over Fast SCSI include the following:
•

Maximum transfer rate increases from 10 MHz to 20 MHz

•

Maximum wide bus bandwidth increases from 20 MB/s to 40 MB/s

•

VHDCI (very high density cable interconnect) cables and connectors
are significantly thinner and smaller

UltraSCSI domain
A single, logical UltraSCSI bus composed of multiple diverse bus segments.
See also bus segment.
UltraSCSI RAID enclosure
A 24-SBB RAID shelf, such as the DS–BA370.

Glossary–16 UltraSCSI RAID Enclosure

Glossary

UltraSCSI RAID subsystem
One or more UltraSCSI RAID enclosures mounted in either a pedestal or a
cabinet. Each subsystem requires a master enclosure. Installing one or two
expansion enclosures and interconnecting all the enclosures with UltraSCSI
bus cables creates an expanded subsystem.
Underwriters Laboratories
See UL.
universal ac input power supply
See shelf power supply.
VHDCI
Very High Density Cable Interface. A 68–pin interface with connectors on
0.8 mm centers. Required for UltraSCSI.
warm swap
A method of device replacement whereby the complete system remains
on-line during device removal or insertion. During device insertion or
removal the bus may halt for a brief period of time. Until the replacement
System booting or code loading cannot occur until insertion of the
replacement device. There is no noticeable impact on user applications that
are not dependent upon the devices on the “affected” SCSI bus.
See also cold swap and hot swap.

UltraSCSI RAID Enclosure Glossary–17

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