Compaq DS-DWZZH-05 Technical manual

TruCluster Software Products
Hardware Configuration Technical Update for
DS-DWZZH-05 UltraSCSI Hub
December 1998
Product Version: TruCluster Production Server
Software Software Version 1.4A and
TruCluster Production Server
Software Version 1.5 and TruCluster
Available Server Software 1.4A and
TruCluster Available Server Software
Version 1.5
Operating System and Version: Compaq’s DIGITAL UNIX Version
4.0B and Compaq’s DIGITAL UNIX
Version 4.0D
This technical update describes how to configure the DS-DWZZH-05
UltraSCSI hub in a TruCluster Software Products environment.
Compaq Computer Corporation
Houston, Texas

© Compaq Computer Corporation 1998
All rights reserved.
The following are trademarks of Compaq Computer Corporation: ALL–IN–1, Alpha AXP,
AlphaGeneration, AlphaServer, AltaVista, ATMworks, AXP, Bookreader, CDA, DDIS, DEC, DEC Ada,
DEC Fortran, DEC FUSE, DECnet, DECstation, DECsystem, DECterm, DECUS, DECwindows, DTIF,
Massbus, MicroVAX, OpenVMS, POLYCENTER, PrintServer, Q–bus, StorageWorks, TruCluster, ULTRIX,
ULTRIX Mail Connection, ULTRIX Worksystem Software, UNIBUS, VAX, VAXstation, VMS, XUI, and
the Compaq logo.
Prestoserve is a trademark of Legato Systems, Inc.; the trademark and software are licensed to Compaq
Computer Corporation by Legato Systems, Inc. NFS is a registered trademark of Sun Microsystems, Inc.
Open Software Foundation, OSF, OSF/1, OSF/Motif, and Motif are trademarks of the Open Software
Foundation, Inc. UNIX is a registered trademark in the United States and other countries, licensed
exclusively through X/Open Company, Ltd. MEMORY CHANNEL is a trademark of Encore Computer
Corporation.
Restricted Rights: Use, duplication, or disclosure by the U.S. Government is subject to restrictions as set
forth in subparagraph (c) (1) (ii).
Compaq Computer 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 Compaq or an authorized sublicensor.
Compaq conducts its business in a manner that conserves the environment and protects the safety and
health of its employees, customers, and the community.

Contents
About This Technical Update
1 DS-DWZZH-05 UltraSCSI Hub
1.1 General Overview ..................................................... 1–1
1.2 DS-DWZZH Overview ................................................ 1–2
2 Using the DS-DWZZH-05 UltraSCSI Hub in a Cluster Configuration
2.1 DS-DWZZH-05 UltraSCSI Hub Description ..................... 2–1
2.2 DS-DWZZH-05 Configuration Guidelines ........................ 2–1
2.3 DS-DWZZH-05 Fair Arbitration ................................... 2–3
2.4 DS-DWZZH-05 Address Configurations .......................... 2–4
2.5 SCSI Bus Termination Power ...................................... 2–6
2.6 DS-DWZZH-05 Indicators ........................................... 2–6
2.7 Configuring a Cluster with a DS-DWZZH-05 .................... 2–6
2.7.1 Installing the DS-DWZZH-05 UltraSCSI Hub .............. 2–7
2.7.2 Checking the Host Adapter and Cabling it to the Hub ... 2–7
2.7.3 Cabling the RAID array Storage Subsystem to the
DS-DWZZH-05 UltraSCSI Hub ................................ 2–8
2.7.3.1 Cabling an HSZ50 to a DS-DWZZH-05 UltraSCSI
Hub ............................................................ 2–8
2.7.3.2 Cabling an HSZ70 to a DS-DWZZH-05 UltraSCSI
Hub ............................................................ 2–10
Figures
2–1 DS-DWZZH-05 Front View .......................................... 2–5
2–2 DS-DWZZH-05 Rear View ........................................... 2–6
2–3 TruCluster Configuration Using KZPSA SCSI Adapters, a
DS-DWZZH-05 UltraSCSI Hub, and an HSZ50 RAID Array
Controller .............................................................. 2–9
Contents iii

2–4 TruCluster Configuration Using a KZPBA-CB UltraSCSI
Adapter, a DS-DWZZH-05 UltraSCSI Hub, and an HSZ70
RAID Array Controller .............................................. 2–11
Tables
2–1 DS-DWZZH UltraSCSI Hub Maximum Configurations ........ 2–2
2–2 Hardware Components Used in the Configuration Shown in
Figure 2–3 ............................................................. 2–10
2–3 Hardware Components Used in the Configuration Shown in
Figure 2–4 ............................................................. 2–12
iv Contents

About This Technical Update
This technical update provides important information about using the
DS-DWZZH-05 UltraSCSI hub with the TruClusterTM software products.
Audience
If you plan to use a DS-DWZZH-05 UltraSCSI hub in a TruCluster
hardware configuration, read this addendum to the TruCluster Software
Products Hardware Configuration manual.
Organization
This technical update contains an introductory chapter and a chapter
covering the use and configuration of the DS-DWZZH-05 UltraSCSI hub in
a TruCluster configuration.
About This Technical Update v

1
DS-DWZZH-05 UltraSCSI Hub
This technical update to the TruCluster Software Products Hardware
Configuration manual provides important information about support for
the DS-DWZZH-05 UltraSCSI hub with the TruCluster Production Server
Software Version 1.4A and TruCluster Production Server Software Version
1.5 and TruCluster Available Server Software Version 1.4A and TruCluster
Available Server Software Version 1.5 products.
1.1 General Overview
The DS-DWZZH-05 UltraSCSI hub was recently qualified for use with the
TruCluster Production Server Software Version 1.4A and TruCluster
Production Server Software Version 1.5 and TruCluster Available Server
Software Version 1.4A and TruCluster Available Server Software Version
1.5 products.
The KZPSA-BB and KZPBA-CB host adpaters are supported for use with
the DS-DWZZH-05 UltraSCSI hub in TruCluster configurations with an
HSZ50 or HSZ70 RAID array controller.
_______________________ Note _______________________
The KZPBA-CB UltraSCSI host adapter is only supported on
TruCluster Production Server Software Version 1.5 and
TruCluster Available Server Software Version 1.5 with Compaq’s
DIGITAL UNIX Version 4.0D after installation of the following
operating system patch. The DIGITAL UNIX and TruCluster
patches are included in one kit.
Compaq’s DIGITAL UNIX V4.0D/TCR 1.5 Patch Kit 3
DUV40DAS00003-19981208.tar (or later)
The patch may be obtained from the Software Patch (ECO)
Access Web site by selecting Software Patches at the following
URL:
http://www.service.digital.com/patches/
There is no TruCluster Software Products software release that coincides
with the availability of support for the DS-DWZZH-05 UltraSCSI hub, so
DS-DWZZH-05 UltraSCSI Hub 1–1

this technical update provides the DS-DWZZH-05 configuration information
that would appear in Chapter 4 of the TruCluster Software Products
Hardware Configuration manual.
1.2 DS-DWZZH Overview
The DS-DWZZH series UltraSCSI hubs are SCSI-2 and draft SCSI-3
compliant SCSI 16-bit signal converters capable of data transfer rates of up
to 40 MB per second. Cluster member systems and HSZ50 or HSZ70 RAID
array controllers are radially connected to the hub ports.
A DS-DWZZH UltraSCSI hub:
• Improves the reliability of the detection of cable faults.
• Provides for bus isolation of cluster systems while allowing the
remaining connections to continue to operate.
• Allows for more separation of systems and storage in a cluster
configuration because each SCSI bus segment can be up to 25 meters in
length. This allows a total separation of nearly 50 meters between a
system and the storage.
For more information on the DS-DWZZH-05 UltraSCSI hub, see the
following documents:
•DWZZH 16-Bit UltraSCSI Hub User’s Guide (EK-DWZZH-UG)
•Shared Storage for DIGITAL UNIX Using UltraSCSI Hubs
(EK-SMA20-AN)
•StorageWorks Solutions BA356-SB 16-Bit Shelf User’s Guide
(EK-BA356-UG)
1–2 DS-DWZZH-05 UltraSCSI Hub

2
Using the DS-DWZZH-05 UltraSCSI Hub
in a Cluster Configuration
2.1 DS-DWZZH-05 UltraSCSI Hub Description
The DS-DWZZH-05 UltraSCSI hub is supported on TruCluster Available
Server Software Version 1.4A and TruCluster Available Server Software
Version 1.5 and TruCluster Production Server Software Version 1.4A and
TruCluster Production Server Software Version 1.5.
The DS-DWZZH-05:
• Is a 5.25-inch StorageWorks Building Block (SBB)
• Has five VHDCI differential SCSI bus connectors
• Uses SCSI ID 7 whether or not fair arbitration mode is enabled.
Therefore, you cannot use SCSI ID 7 for a RAID array controller or for
the member systems’ SCSI bus adapter.
• Contains internal termination for each port; therefore, it terminates the
hub end of each SCSI bus segment.
_____________________ Note _____________________
Do not put trilinks on the DS-DWZZH-05 as it is not possible
to remove the DS-DWZZH-05 internal termination.
• Requires that termination power (termpwr) be provided by the SCSI
bus host adapters on each SCSI bus segment.
_____________________ Note _____________________
The DS-DWZZH-05 is designed to sense loss of termination
power (such as a cable pull or termpwr not enabled on the
host adapter) and shut down the applicable port to prevent
corrupted signals on the remaining SCSI bus segments.
2.2 DS-DWZZH-05 Configuration Guidelines
The DS-DWZZH-05 UltraSCSI hub can be installed in:
Using the DS-DWZZH-05 UltraSCSI Hub in a Cluster Configuration 2–1

• A StorageWorks DS-BA356 shelf (which has the required 180-watt
power supply).
• A wide BA356 which has been upgraded to the 180-watt power supply
with the DS-BA35X-HH option.
_____________________ Note _____________________
Dual power supplies are recommended for any BA356 shelf
containing a DS-DWZZH-05 UltraSCSI hub in order to
provide a higher level of availability between cluster member
systems and storage.
• The lower righthand device slot of the BA370 shelf within the RA7000
or ESA 10000 RAID array subsystems. This position minimizes cable
lengths and interference with disks.
A DS-DWZZH-05 UltraSCSI hub uses the DS-BA356, BA356, or BA370
shelf only to provide its power and mechanical support (it is not connected
to the shelf internal SCSI bus).
Maximum configurations with combinations of DS-DWZZH-03 (see
technical update TU-DWZZH-03) and DS-DWZZH-05 UltraSCSI hubs, and
disks in the same DS-BA356 or BA356 storage shelf containing dual
180-watt power supplies are shown in Table 2–1.
_______________________ Note _______________________
With dual 180-watt power supplies installed, there are slots
available for six 3.5-inch SBBs or two 5.25-inch SBBs.
Table 2–1: DS-DWZZH UltraSCSI Hub Maximum Configurations
DS-DWZZH-03 DW-DWZZH-05 Disk DrivesaPersonality
Modulebc
5 0 0 Not Installed
4 0 0 Installed
3 0 3 Installed
2 0 4 Installed
1 0 5 Installed
0 2 0 Not Installed
3 1 0 Not Installed
2 1 1 Installed
2–2 Using the DS-DWZZH-05 UltraSCSI Hub in a Cluster Configuration

Table 2–1: DS-DWZZH UltraSCSI Hub Maximum Configurations (cont.)
DS-DWZZH-03 DW-DWZZH-05 Disk DrivesaPersonality
Modulebc
1 1 2 Installed
0 1 3 Installed
aDS-DWZZH UltraSCSI hubs and disk drives may coexist in a storage shelf. Installed disk drives are not
associated with the DS-DWZZH UltraSCSI hub SCSI bus segments; they are on the SCSI bus connected to
the personality module.
bIf the personality module is installed, you can install a maximum of four DS-DWZZH-03 UltraSCSI hubs.
cThe personality module must be installed to provide a path to any disks installed in the BA356 or
DS-BA356 shelf.
2.3 DS-DWZZH-05 Fair Arbitration
Although each cluster member system and storage controller connected to
an UltraSCSI hub are on separate SCSI bus segments, they all share a
common SCSI bus and its bandwidth. As the number of systems accessing
the storage controllers increases, it is likely that the adapter with the
highest priority SCSI ID will obtain a higher proportion of the UltraSCSI
bandwidth.
The DS-DWZZH-05 UltraSCSI hub provides a fair arbitration feature that
overrides the traditional SCSI bus priority. Fair arbitration applies only to
the member systems, not to the storage controllers (which are assigned
higher priority than the member system host adapters).
You enable fair arbitration by placing the switch on the front of the
DS-DWZZH-05 UltraSCSI hub to the Fair position (see Figure 2–1).
Fair arbitration works as follows. The DS-DWZZH-05 UltraSCSI hub is
assigned the highest SCSI ID, which is 7. During the SCSI arbitration
phase, the hub, because it has the highest priority, captures the SCSI ID of
all host adapters arbitrating for the bus. The hub compares the SCSI IDs of
the host adapters requesting use of the SCSI bus, and then allows the
device with the highest priority SCSI ID to take control of the SCSI bus.
That SCSI ID is removed from the group of captured SCSI IDs prior to the
next comparison.
After the host adapter has been serviced, if there are still SCSI IDs retained
from the previous arbitration cycle, the next highest SCSI ID is serviced.
When all devices in the group have been serviced, the DS-DWZZH-05
repeats the sequence at the next arbitration cycle.
Fair arbitration is disabled by placing the switch on the front of the
DS-DWZZH-05 UltraSCSI hub in the Disable position (see Figure 2–1).
With fair arbitration disabled, the SCSI requests are serviced in the
Using the DS-DWZZH-05 UltraSCSI Hub in a Cluster Configuration 2–3

conventional manner; the highest SCSI ID asserted during the arbitration
cycle obtains use of the SCSI bus.
_______________________ Note _______________________
Host port SCSI ID assignments are not linked to the physical
port when fair arbitration is disabled.
The DS-DWZZH-05 retains SCSI ID 7 regardless of whether fair
aarbitrarion is enabled or not.
2.4 DS-DWZZH-05 Address Configurations
The DS-DWZZH-05 has two addressing modes; wide addressing mode and
narrow addressing mode. With either addressing mode, if fair arbitration is
enabled, each hub port is assigned a specific SCSI ID. This allows the fair
arbitration logic in the hub to identify the SCSI ID of the device
participating in the arbitration phase of the fair arbitration cycle.
_____________________ Caution _____________________
If fair arbitration is enabled, The SCSI ID of the host adapter
must match the SCSI ID assigned to the hub port. Mismatching
or duplicating SCSI IDs will cause the hub to hang.
SCSI ID 7 is reserved for the DS-DWZZH-05 whether fair
arbitration is enabled or not.
Jumper W1, accessible from the rear of the DS-DWZZH-05 (see Figure 2–2)
determines which addressing mode is used. The jumper is installed to
select narrow addressing mode and is presently the only addressing mode
supported with Compaq’s DIGITAL UNIX operating system. If fair
arbitration is enabled, the SCSI IDs for the host adapters are 0, 1, 2, and 3
(see the port numbers not in parentheses in Figure 2–1). The controller
ports are assigned SCSI IDs 4 through 6, and the hub uses SCSI ID 7.
If jumper W1 is removed, the host adapter ports assume SCSI IDs 12, 13,
14, and 15. The controllers are assigned SCSI IDs 0 through 6. The
DS-DWZZH-05 retains the SCSI ID of 7.
2–4 Using the DS-DWZZH-05 UltraSCSI Hub in a Cluster Configuration

Figure 2–1: DS-DWZZH-05 Front View
Fair Disable
Host Port
SCSI ID
1
(13)
Host Port
SCSI ID
3
(15)
Controller
Port
SCSI ID
6 - 4
(6 - 0)
Busy
0
2
ZK-1447U-AI
Host Port
Host Port
SCSI ID
SCSI ID
(14)
Power
(12)
Using the DS-DWZZH-05 UltraSCSI Hub in a Cluster Configuration 2–5

Figure 2–2: DS-DWZZH-05 Rear View
W1 ZK-1448U-AI
2.5 SCSI Bus Termination Power
Each host adapter connected to a DS-DWZZH-05 UltraSCSI hub port must
supply termination power (termpwr) to enable the termination resistors on
each end of the SCSI bus segment. If the host adapter is disconnected from
the hub, the port is disabled. Only the UltraSCSI bus segment losing
termination power is affected. The remainder of the SCSI bus operates
normally.
2.6 DS-DWZZH-05 Indicators
The DS-DWZZH-05 has two indicators on the front panel (see Figure 2–1).
The green LED indicates that power is applied to the hub. The yellow LED
indicates that the SCSI bus is busy.
2.7 Configuring a Cluster with a DS-DWZZH-05
The following sections discuss how to configure a DS-DWZZH-05 UltraSCSI
hub in a TruCluster configuration.
2–6 Using the DS-DWZZH-05 UltraSCSI Hub in a Cluster Configuration

To configure a TruCluster configuration using a DS-DWZZH-05 UltraSCSI
hub, follow these steps:
1. Configure and install the DS-DWZZH-05 UltraSCSI hub (Section 2.7.1)
2. Verify that the host adapter termination is installed and cable the host
adapter to the DS-DWZZH-05 UltraSCSI hub (Section 2.7.2)
3. Cable the RAID array controller to the hub:
• HSZ50 (Section 2.7.3.1)
• HSZ70 (Section 2.7.3.2)
2.7.1 Installing the DS-DWZZH-05 UltraSCSI Hub
All existing versions of Compaq’s DIGITAL UNIX operating systems
support only eight devices on a SCSI bus. Therefore, narrow addressing
mode must be used.
Install the DS-DWZZH-05 UltraSCSI hub as follows:
1. Install the W1 jumper to enable narrow addressing mode (see
Figure 2–2).
2. If fair arbitration is to be used, ensure that the switch on the front of
the DS-DWZZH-05 UltraSCSI hub is in the Fair position.
3. Install the DW-DWZZH-05 UltraSCSI hub in a DS-BA356, BA356 (if it
has the required 180-watt power supply), or BA370 storage shelf.
2.7.2 Checking the Host Adapter and Cabling it to the Hub
At the present time only the KZPSA-BB and KZPBA-CB host adpaters are
supported for use with the DS-DWZZH-05 UltraSCSI hub in TruCluster
configurations with an HSZ50 or HSZ70 RAID array controller.
See the TruCluster Software Products Hardware Configuration manual and
Hardware Configuration Technical Update for DS-KZPBA-CB and verify
the following:
• Ensure that the KZPSA-BB termination resistor SIPs (Z1 through Z5)
or KZPBA-CB termination resistors (RM1 through RM8) are installed.
• If fair arbitration is selected on the DS-DWZZH-05 UltraSCSI hub,
ensure that the host adapter SCSI ID matches the controller port SCSI
ID on the DS-DWZZH-05 for the port that the adapter will be cabled to.
Using the DS-DWZZH-05 UltraSCSI Hub in a Cluster Configuration 2–7

• Ensure that no member systems’ host adapter SCSI ID is set at 7
(because the DS-DWZZH-05 uses SCSI ID 7).
• Connect a BN38C cable between the host adapter and the appropriate
DS-DWZZH-05 UltraSCSI hub port. Each connection forms a SCSI bus
segment with the host adapter and the hub. The maximum length of a
SCSI bus segment, including cable and internal device bus length, is 25
meters.
2.7.3 Cabling the RAID array Storage Subsystem to the
DS-DWZZH-05 UltraSCSI Hub
To prepare the storage portion of a cluster using HSZ50 or HSZ70 RAID
Array controllers, see Section 2.7.3.1 and Section 2.7.3.2.
_______________________ Note _______________________
Ensure that the SCSI IDs assigned to the RAID array controllers
are not the same as a SCSI ID assigned to a KZPSA-BB or
KZPBA-CB SCSI adapter (0, 1, 2, or 3 if fair arbitration is
enabled) or the SCSI ID assigned to the DS-DWZZH-05 (7).
2.7.3.1 Cabling an HSZ50 to a DS-DWZZH-05 UltraSCSI Hub
To prepare the storage portion of a cluster using HSZ50 RAID Array
controllers, follow these steps while referring to Figure 2–3 and Table 2–2:
1. Attach an H885-AA trilink connector to each HSZ50 controller on the
SCSI bus segment.
2. Attach an H879-AA terminator to the H885-AA trilink connector on
the HSZ50 controller that will be on the end of the SCSI bus segment.
3. If there are two HSZ50 controllers, connect the two H885-AA trilinks
on the controllers with a BN21K (or BN21L) cable.
4. Connect the DS-DWZZH-05 UltraSCSI hub to the open H885-AA
connector on the HSZ50 with a BN38C cable. The length of any SCSI
bus segment must not exceed 25 meters.
_____________________ Note _____________________
One end of the BN38C cable is 68-pin high density. The
other end is 68-pin VHDCI. The DS-DWZZH-05 accepts the
68-pin VHDCI connector.
2–8 Using the DS-DWZZH-05 UltraSCSI Hub in a Cluster Configuration

Figure 2–3 shows a sample configuration that uses KZPSA-BB SCSI
adapters, a DS-DWZZH-05 UltraSCSI hub, and an HSZ50 RAID array
controller.
Figure 2–3: TruCluster Configuration Using KZPSA SCSI Adapters, a
DS-DWZZH-05 UltraSCSI Hub, and an HSZ50 RAID Array Controller
TT
TT
TT
HSZ50
HSZ50
T
1
DS-DWZZH-05
KZPSA-BB
KZPSA-BB
1
1
1
AlphaServer
Member
System 2
T
KZPSA-BB
AlphaServer
Member
System 1
AlphaServer
Member
System 3
T
KZPSA-BB
AlphaServer
Member
System 4
T
2
1
4
3
2
ZK-1449U-AI
_______________________ Note _______________________
The systems shown in Figure 2–3 use KZPSA-BB SCSI
adapters. They could be KZPBA-CB UltraSCSI adapters without
changing any cables in the configuration.
Table 2–2 shows the components used to create the cluster shown in
Figure 2–3.
Using the DS-DWZZH-05 UltraSCSI Hub in a Cluster Configuration 2–9

Table 2–2: Hardware Components Used in the Configuration Shown in
Figure 2–3
Callout Number Description
1BN38C HD68 to VHDCI cableab
2 H885-AA HD68 trilink connector
3 H879-AA HD68 terminator
4 BN21K or BN21L HD68 cableb
aThe maximum length of the SCSI bus segment, including BN38C cable and internal device length, must
not exceed 25 meters.
bThe maximum length of the SCSI bus segment, including the combined length of the BN38C and BN21K
(or BN21L) cables, must not exceed 25 meters.
2.7.3.2 Cabling an HSZ70 to a DS-DWZZH-05 UltraSCSI Hub
To prepare the storage portion of a cluster using HSZ70 RAID array
controllers, follow these steps while referring to Figure 2–4 and Table 2–3:
1. Install an H8861-AA trilink connector on each HSZ70 controller port
on the SCSI bus segment.
2. Attach an H8863-AA terminator to the H8861-AA connector on the
HSZ70 controller that will be on the end of the SCSI bus segment.
3. If there are two HSZ70 controllers, connect the two H8861-AA trilink
connectors on the controllers with a BN37A cable.
4. Connect the DS-DWZZH-05 to the HSZ70 H8861-AA trilink with a
BN37A cable.
_____________________ Note _____________________
The maximum length of a SCSI bus segment, including
cable and internal device SCSI bus length must not exceed
25 meters.
Figure 2–4 shows a sample configuration that uses a KZPBA-CB SCSI
adapter, a DS-DWZZH-05 UltraSCSI hub, and an HSZ70 RAID array
controller.
2–10 Using the DS-DWZZH-05 UltraSCSI Hub in a Cluster Configuration

Figure 2–4: TruCluster Configuration Using a KZPBA-CB UltraSCSI
Adapter, a DS-DWZZH-05 UltraSCSI Hub, and an HSZ70 RAID Array
Controller
TT
TT
TT
HSZ70
HSZ70
T
1
DS-DWZZH-05
KZPBA-CB
KZPBA-CB
1
1
1
AlphaServer
Member
System 2
T
KZPBA-CB
AlphaServer
Member
System 1
AlphaServer
Member
System 3
T
KZPBA-CB
AlphaServer
Member
System 4
T
2
4
4
3
2
ZK-1460U-AI
_______________________ Note _______________________
The systems shown in Figure 2–4 use KZPBA-CB UltraSCSI
adapters. They could be KZPSA-BB SCSI adapters without
changing any cables in the configuration.
Table 2–3 shows the components used to create the cluster shown in
Figure 2–4.
Using the DS-DWZZH-05 UltraSCSI Hub in a Cluster Configuration 2–11

Table 2–3: Hardware Components Used in the Configuration Shown in
Figure 2–4
Callout Number Description
1BN38C HD68 to VHDCI cablea
2 H8861-AA VHDCI trilink connector
3 H8863-AA VHDCI terminator
4 BN37A VHDCI cableb
aThe maximum length of the SCSI bus segment, including BN38C cable and internal device length, must
not exceed 25 meters.
bThe maximum length of the SCSI bus segment, including the combined length, of BN37A cables and
internal device length, must not exceed 25 meters.
2–12 Using the DS-DWZZH-05 UltraSCSI Hub in a Cluster Configuration