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EK-410AB-MG-D01

October 1994

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Document:	DSSI VMScluster Installation and Troubleshooting Guide
Order Number:	EK-410AB-MG
Revision:	D01
Pages:	102
Original Filename:	https://manx-docs.org/collections/mds-199909/cd1/cluster/410abmgd.pdf

OCR Text

DSSI VMScluster
Installation and Troubleshooting
Guide
Order Number: EK–410AB–MG. D01

Digital Equipment Corporation
Maynard, Massachusetts

First Printing, October 1994
The information in this document is subject to change without notice and should not be
construed as a commitment by Digital Equipment Corporation.
Digital Equipment Corporation makes no representation that the use of its products in
the manner described in the 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 sofware described in this publication is authorized
only pursuant to a valid written license from Digital or an authorized sublicensor.
Copyright © Digital Equipment Corporation, 1994. All Rights reserved.
The Reader’s Comments form at the end of this document requests your critical
evaluation to assist in preparing future documentation.
The following are trademarks of Digital Equipment Corporation: Alpha AXP, AXP,
DEC, DECnet, Digital, MicroVAX, OpenVMS, VAX, VAX DOCUMENT, VAXcluster,
VMScluster, the AXP logo, and the DIGITAL logo.
OSF/1 is a registered trademark of Open Software Foundation, Inc.
All other trademarks and registered trademarks are the property of their respective
holders.
FCC NOTICE: The equipment described in this manual 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 computing device pursuant to Subpart J of Part 15 of FCC
Rules, which are designed to provide reasonable protection against such radio frequency
interference when operated in a commercial environment. Operation of this equipment
in a residential area may cause interference, in which case the user at his own expense
may be required to take measures to correct the interference.

S2555

This document was prepared using VAX DOCUMENT Version 2.1.

Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1 DSSI VMScluster Configuration and Requirements
Introducing VMScluster Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VMScluster Capabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
In This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DSSI VMScluster Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Three Types of DSSI VMScluster Configurations . . . . . . . . . . . . . . . .
DSSI Nodes Per Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DSSI VMScluster Restrictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Restrictions for AXP-Only DSSI VMScluster Systems . . . . . . . . . . . . .
Restrictions for Dual-Architecture DSSI VMScluster Systems . . . . . .
Restrictions for VAX-Only DSSI VMScluster Systems . . . . . . . . . . . . .
Licensing and Software Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Software Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DSSI Bus Lengths and Grounding Requirements . . . . . . . . . . . . . . . . . . .
Maximum Bus Lengths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintain a Common Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Verify Site Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Offset Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Measuring Grounding Offset Voltage . . . . . . . . . . . . . . . . . . . . . . . . . .
Install Grounding Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum Number of Enclosures . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended Guidelines for DSSI VMScluster Systems . . . . . . . . . . . . .
General Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DSSI Adapter Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1–1
1–1
1–1
1–1
1–1
1–2
1–3
1–3
1–4
1–4
1–5
1–5
1–5
1–5
1–6
1–6
1–6
1–6
1–7
1–7
1–7
1–7
1–8

2 Installation: AXP-Only or Dual-Architecture (AXP and VAX)
Configurations
In this Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examples of Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Step 1: Configure Bus Node IDs for Host Adapters . . . . . . . . . . . . . . . . .
DSSI Adapter Bus Node IDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
KFESA Adapter IDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DEC 4000 AXP Adapter IDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
HSD30 Array Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
KFMSB Adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing the KFESA Adapter Bus Node ID (AlphaServer 2000/2100
Systems) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Running the ECU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Turn Off System Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2–1
2–1
2–5
2–5
2–5
2–5
2–5
2–5
2–5
2–5
2–7

iii

Changing NCRn_SETUP Environment Variables (DEC 4000 AXP
Systems) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Set Bus Mode and Bus Node Numbers . . . . . . . . . . . . . . . . . . . . . . . .
Use NCRn_SETUP Environment Variables . . . . . . . . . . . . . . . . . . . . .
Host Adapters and Bus Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example: Set NCRn_SETUP Variables . . . . . . . . . . . . . . . . . . . . . . . .
Turn Off System Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing the HSD30 Array Controller Bus Node IDs . . . . . . . . . . . . . . . .
Set this_controller ID; Set other_controller ID . . . . . . . . . . . . . . . . . .
HSD30 Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing the KFMSB Host Adapter Bus Node IDs . . . . . . . . . . . . . . . . .
Loadable Firmware Update Utility . . . . . . . . . . . . . . . . . . . . . . . . . . .
Step 2: Configure Bus Node ID Plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unique Bus Node ID Plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Step 3: Set HSD05 Array Controller Bus Node ID . . . . . . . . . . . . . . . . . .
HSD05 Bus Node ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Step 4: Connect Ground Cables Between Enclosures . . . . . . . . . . . . . . . .
Daisy Chain Ground Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Step 5: Connect DSSI Cables Between Enclosures . . . . . . . . . . . . . . . . . .
DSSI Connectors and Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Check Devices on the Configuration Display . . . . . . . . . . . . . . . . . . . .
Step 6: Set DSSI Device Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DSSI Device Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
For More Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
cdp Console Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Command Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DSSI Parameters Displayed Using cdp . . . . . . . . . . . . . . . . . . . . . . . .
cdp Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
set host -dup -dssi Command (HSD05/HDS30) . . . . . . . . . . . . . . . . . .
Starting DUP: Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting Allocation Class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting Unit Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting Node Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exiting the DUP Server Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Step 7: Configure SCSI Node ID Plugs . . . . . . . . . . . . . . . . . . . . . . . . . . .
When to Change SCSI Node Plugs . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example with Conflicting SCSI Device Names . . . . . . . . . . . . . . . . . .
Example with Unique SCSI Device Names . . . . . . . . . . . . . . . . . . . . .
Step 8: Set Boot Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Boot Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Boot Parameter Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Step 9: Complete the Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2–7
2–7
2–7
2–8
2–8
2–9
2–9
2–9
2–9
2–10
2–10
2–11
2–11
2–11
2–11
2–12
2–12
2–12
2–12
2–14
2–14
2–14
2–15
2–15
2–16
2–16
2–17
2–17
2–18
2–18
2–19
2–19
2–20
2–21
2–21
2–21
2–21
2–24
2–24
2–25
2–25

3 Installation: VAX-Only Configuration
In This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examples of Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Step 1: Configure Bus Node IDs for Host Adapters and Mass Storage
Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unique Bus Node ID Plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Host Adapters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SET DSSI_ID and SHOW DSSI_ID Commands . . . . . . . . . . . . . . . . .
SET DSSI_ID Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
HSD30 Array Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3–1
3–1
3–3
3–3
3–3
3–3
3–4
3–4

HSD30 Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
HSD05 Bus Node ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Turn Off System Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Step 2: Connect Ground Cables Between Enclosures . . . . . . . . . . . . . . . .
Daisy Chain Ground Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Step 3: Connect DSSI Cables Between Enclosures . . . . . . . . . . . . . . . . . .
DSSI Connectors and Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Check Devices Using the Show DSSI Command . . . . . . . . . . . . . . . . .
Step 4: Set DSSI Device Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DSSI Device Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
For More Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SET HOST Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starting DUP: Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting Allocation Class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting Unit Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting Node Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exiting the DUP Server Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Step 5: Configure SCSI Node IDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
When to Change SCSI Node Plugs . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example with Conflicting SCSI Device Names . . . . . . . . . . . . . . . . . .
Example with Unique SCSI Device Names . . . . . . . . . . . . . . . . . . . . .
Step 6: Set Boot Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Boot Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Boot Parameter Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Step 7: Complete the Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3–5
3–5
3–5
3–6
3–6
3–6
3–6
3–8
3–8
3–8
3–9
3–9
3–9
3–10
3–10
3–11
3–12
3–13
3–13
3–13
3–13
3–16
3–16
3–16
3–16

4 Troubleshooting
Troubleshooting Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
In This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Common Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Symptoms and Corrective Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DSSI Node Fails to Boot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Termination Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Grounding and Bus Lengths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DSSI-Related Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
For More Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4–1
4–1
4–1
4–1
4–5
4–6
4–6
4–6
4–7

A Electrical Lengths By Enclosure
DSSI Bus Lengths by Enclosure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lengths of Interconnects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A–1
A–1

B Storage Device Parameters
Examining Storage Device Parameters on AXP Systems . . . . . . . . . . . . .
show device Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examining DSSI Device Parameters on VAX Systems . . . . . . . . . . . . . . .
SHOW DSSI Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SHOW DSSI Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SHOW UQSSP Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SHOW UQSSP Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DSSI Device Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Principal Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

B–1
B–1
B–2
B–2
B–3
B–4
B–4
B–5
B–5

Parameter Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How OpenVMS AXP Uses the DSSI Device Parameters . . . . . . . . . . . . . .
Allocation Class Zero . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nonzero Allocation Class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Multiple and Shared Buses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example of Duplicate Device Names . . . . . . . . . . . . . . . . . . . . . . . . . .

B–5
B–7
B–7
B–8
B–8
B–8

C Sample DSSI VMScluster Configurations for VAX Systems
Configuration Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Combinations of Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adapters and System Performance . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuring for High Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuring for Storage Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuring for Data Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sample Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

C–1
C–1
C–1
C–1
C–2
C–2
C–6

AXP-Only DSSI VMScluster: Two AlphaServer 2100 Systems . . . . . .
AXP-Only DSSI VMScluster: Two DEC 4000 Systems . . . . . . . . . . . .
Dual-Architecture DSSI VMScluster: AlphaServer 2100 Systems and
VAX 4000 Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dual-Architecture DSSI VMScluster: DEC 4000 Systems and VAX
4000 System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Midrange and Pedestal Style DSSI Connectors . . . . . . . . . . . . . . . . . .
Configuration with Duplicate SCSI Device Names . . . . . . . . . . . . . . .
Expanded Two-System DSSI VMScluster . . . . . . . . . . . . . . . . . . . . . .
Midrange and Pedestal Style DSSI Connectors . . . . . . . . . . . . . . . . . .
Configuration with Duplicate SCSI Device Names . . . . . . . . . . . . . . .
How OpenVMS Sees Unit Numbers for DSSI Devices . . . . . . . . . . . . .
Directly Shared Disks for High Performance . . . . . . . . . . . . . . . . . . . .
Configuring for Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using Multiple DSSI Interconnects for Redundancy . . . . . . . . . . . . . .
Two-System DSSI VMScluster with Maximum Shared Storage . . . . .
Three-System DSSI VMScluster Using Three DSSI Interconnects . . .
Three-System DSSI VMScluster Using Four DSSI Interconnects . . . .

2–2
2–2

2–4
2–12
2–22
3–2
3–6
3–14
B–9
C–2
C–3
C–5
C–7
C–9
C–11

Licensing and Software Requirements for DSSI VMScluster
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Acceptable Ground Offset Limits by Length of DSSI Interconnect . . .
DSSI Adapter Characteristics for AXP Supported Adapters . . . . . . . .
Host Adapters for DEC 4000 AXP Systems . . . . . . . . . . . . . . . . . . . . .
DSSI Cable Variations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuration with Conflicting SCSI Device Names . . . . . . . . . . . . . .

1–5
1–6
1–8
2–8
2–13
2–22

Index
Figures
2–1
2–2
2–3
2–4
2–5
2–6
3–1
3–2
3–3
B–1
C–1
C–2
C–3
C–4
C–5
C–6

2–3

Tables
1–1
1–2
1–3
2–1
2–2
2–3

2–4
2–5
3–1
3–2
3–3
3–4
3–5
4–1
4–2
4–3
4–4
A–1

Configuration with Unique SCSI Device Names . . . . . . . . . . . . . . . . .
Boot Parameters for AXP and VAX Systems . . . . . . . . . . . . . . . . . . . .
DSSI Cable Variations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SET HOST Commands According to Host Adapter Type . . . . . . . . . . .
Configuration with Conflicting SCSI Device Names . . . . . . . . . . . . . .
Configuration with Unique SCSI Device Names . . . . . . . . . . . . . . . . .
Boot Parameters for VAX Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Digital AlphaServer 2000/2100 Systems: DSSI Hardware Installation
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DEC 4000 AXP Systems: DSSI Hardware Installation
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VAX Systems: DSSI Hardware Installation Troubleshooting . . . . . . .
DSSI Related Console Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical Lengths of Embedded DSSI Interconnects in Enclosures . .

2–23
2–24
3–7
3–9
3–13
3–15
3–16
4–2
4–3
4–5
4–6
A–1

vii

Preface
Purpose of
This Guide

This guide describes how to install and maintain a DSSI
VMScluster configuration with Alpha AXP systems and VAX
systems.

Who Should
Use This Guide

This guide is intended for system administrators. A system
administrator should be an experienced user who is familiar with
OpenVMS AXP and OpenVMS VAX operating systems.

Structure of
This Guide

This guide is divided into four chapters and three appendixes:

Finding More
Information

•

Chapter 1 describes the types of DSSI VMScluster
configurations you can create, as well as restrictions and
requirements.

•

Chapter 2 describes the hardware-related steps in setting up
a DSSI VMScluster system using AXP-only or VAX and AXP
systems.

•

Chapter 3 describes the hardware-related steps in setting up a
DSSI VMScluster system using only VAX systems.

•

Chapter 4 provides troubleshooting tips for solving hardware
problems within the DSSI VMScluster configuration.

•

Appendix A provides the DSSI connector type and electrical
lengths of DSSI buses for DSSI adapters and enclosures.

•

Appendix B provides information on how to examine storage
device parameters and describes how OpenVMS uses DSSI
parameters.

•

Appendix C provides sample VAX configurations that
emphasize performance, storage capacity, or data availablility.

The following documents provide information related to DSSI
VMScluster systems:
•

VMScluster Systems for OpenVMS

•

OpenVMS AXP Version 6.1 Upgrade and Installation Manual,
AA-PV6XB-TE.

•

OpenVMS AXP Version 5.5-2 Upgrade and Installation Manual

•

AlphaServer 2000/2100/2100 RM/ 2100 CAB Series Service
Guide, EK-KN450-SV.

•

DEC 4000 AXP Model 600/700 Series Service Guide, EKKN430-SV.

•

StorageWorks Solutions HSD05 Array Controller User’s Guide,
EK-HSD05-UG

•

StorageWorks Array Controllers HS Family of Array
Controllers User’s Guide, EK-HSFAM-UG

•

KFESA DSSI Adapter Installation and User’s Guide, EKKFESA-OP

•

KFMSB Adapter Installation Guide, EK-KFMSB-IN

Conventions

The following conventions are used in this guide.

Convention

Meaning

cdp

AXP console commands are indicated by lowercase type.

SHOW DSSI

VAX console commands are indicated by uppercase type.

Caution

Cautions provide information to prevent damage to equipment or
software.

[]

In command format descriptions, brackets indicate optional
elements.

{}

In command descriptions, braces containing items separated by
commas imply mutually exclusive items.

1
DSSI VMScluster Configuration and
Requirements
Introducing VMScluster Systems
VMScluster
Capabilities

A VMScluster is a highly integrated organization of Alpha AXP
computers, VAX computers, or a combination of AXP and VAX
computers.
As members of a VMScluster system, computers can share
processing resources, data storage, and queues under a single
security and management domain, and they can be configured to
boot or fail independently.

In This Chapter

This chapter describes Digital Storage System Interconnect
(DSSI) VMScluster configurations and requirements.
•

DSSI VMScluster Configurations

•

DSSI VMScluster Restrictions

•

Licensing and Software Requirements

•

DSSI Bus Lengths and Grounding Requirements

•

Recommended Guidelines for DSSI VMScluster Systems

DSSI VMScluster Configurations
Three Types
of DSSI
VMScluster
Configurations

Alpha AXP systems can be configured in three types of DSSI
VMScluster configurations:
•

Alpha AXP systems in an AXP only DSSI VMScluster
Up to four Alpha AXP systems can share a DSSI.
Each AlphaServer 2000/2100 system must have a KFESA
DSSI adapter.
DEC 4000 AXP systems can coexist as end nodes on a
DSSI with AlphaServer 2000/2100 systems.

DSSI VMScluster Configuration and Requirements 1–1

DSSI VMScluster Configurations

•

Alpha AXP and VAX systems in a dual-architecture DSSI
VMScluster
Up to four systems (AXP and VAX) can share a DSSI.
AlphaServer 2000/2100 systems using the KFESA DSSI
adapter can coexist as middle node or end nodes on a DSSI
with VAX 4000/6000/7000/10000 systems.
DEC 4000 AXP systems can coexist as end nodes on a
DSSI with VAX 4000/6000/7000/10000 systems.

•

VAX systems in a VAX only DSSI VMScluster
Up to four VAX systems can share a DSSI.
Six DSSI buses per system is the maximum allowable.

DSSI Nodes
Per Bus

Each DSSI bus supports up to eight nodes. Each of the following
counts as one DSSI node:
•

A DSSI adapter

•

An HSD05 array controller

•

An HSD30 array controller

•

An RF-disk controller interface

•

A TF-tape controller interface

For a two-system DSSI VMScluster system, for instance, a
maximum of six RF-disks can be configured per DSSI bus: two
DSSI adapters + six disks = eight nodes.

1–2 DSSI VMScluster Configuration and Requirements

DSSI VMScluster Configurations

Note

Drives connected through the HSD05 and HSD30 array
controllers do not count as DSSI nodes; thus, using
multiple HSD05 controllers, up to 42 SCSI drives can be
configured in a two-system DSSI VMScluster configuration,
provided you have sufficient storage expansion hardware.
AlphaServer 2100 systems using HSD05 array controllers
in the two internal StorageWorks shelves can support
up to 24 SCSI drives in a two-system DSSI VMScluster
configuration.
AlphaServer 2000 systems using HSD05 array controllers
in the internal StorageWorks shelf can support up
to 12 SCSI drives in a two-system DSSI VMScluster
configuration.

DSSI VMScluster Restrictions
Restrictions for
AXP-Only DSSI
VMScluster
Systems

The following restrictions apply to AXP-only DSSI VMScluster
systems.
•

Because the OpenVMS operating system ‘‘names’’ the first
SCSI bus it finds in each system as bus A, the second as bus
B, and so on, SCSI drives in a DSSI VMScluster can appear
to share a common bus between systems. For each SCSI bus
that OpenVMS sees as common to the DSSI VMScluster, the
total number of drives is limited to eight (node ID plugs 0–7).
Note

Disks connected through an SWXCR-xx controller cannot
be striped or shadowed using host-based shadowing.
These disks can be served to the cluster, however. This
restriction is removed with OpenVMS AXP version 6.2.
Hardware shadowing of SCSI disks is supported via the
HSD30 array controller.

•

DEC 4000 AXP systems can only exist as end nodes on a DSSI
bus.

•

AlphaServer 2000 systems cannot be configured with an
HSD05 in the internal StorageWorks shelf—installing an
HSD05 prevents the front door from closing.

DSSI VMScluster Configuration and Requirements 1–3

DSSI VMScluster Restrictions

Restrictions for
Dual-Architecture
DSSI
VMScluster
Systems

The following restrictions apply to dual-architecture DSSI
VMScluster systems.
•

A VAX CPU and an AXP CPU may not boot from a common
system disk. AXP processors must boot from an AXP system
disk, and VAX processors must boot from a VAX system
disk. However, VAX and AXP processors can mount and
share access to files on any disk (including system disks) in a
VMScluster system.

•

AXP CPUs cannot access shadow or stripe sets created on
VAX CPUs by the Volume Shadowing for OpenVMS VAX or
VAX Disk Striping products.

•

Because OpenVMS ‘‘names’’ the first SCSI bus it finds in each
system as bus A, the second as bus B, and so on, SCSI drives
in a DSSI VMScluster can appear to share a common bus
between systems. For each SCSI bus that OpenVMS sees as
common to the DSSI VMScluster, the total number of drives is
limited to eight (node ID plugs 0–7).
Note

Restrictions for
VAX-Only DSSI
VMScluster
Systems

•

DEC 4000 AXP systems can only exist as end nodes on a DSSI
bus.

•

AlphaServer 2000 systems cannot be configured with an
HSD05 in the internal StorageWorks shelf—installing an
HSD05 prevents the front door from closing.

The following restrictions apply to VAX-only DSSI VMScluster
systems.
•

1–4 DSSI VMScluster Configuration and Requirements

Licensing and Software Requirements

Licensing and Software Requirements
Software
Requirements

Table 1–1 provides the licensing and software requirements for
each processor in a DSSI VMScluster system.
Table 1–1 Licensing and Software Requirements for DSSI VMScluster
Systems
Processor License

Operating Software

AXP

VMScluster software license

OpenVMS AXP Version
6.1

VAX

VAXcluster software license

OpenVMS VAX Version
5.5-2 (not Version
A5.5-2)

One full-function DECnet
license1
1 Since DSSI VMScluster systems must also be connected by an Ethernet interconnect for

DECnet communications, a full-function DECnet license is required for the first system.

Additional licensing information is described in the VMScluster
and VAXcluster Software Product Descriptions.

DSSI Bus Lengths and Grounding Requirements
Maximum Bus
Lengths

The maximum DSSI bus length supported, that is, the total
distance between end-node terminators on the DSSI bus, is:
•

25 m (82 ft) in a computer room environment

•

20 m (65.6 ft) in an office environment

Refer to Appendix A for a table of electrical lengths for enclosures.
Note

The maximum DSSI bus length (end-to-end) for HSD05
and HSD30 array controllers is 18.28 m (60 ft).

DSSI VMScluster Configuration and Requirements 1–5

DSSI Bus Lengths and Grounding Requirements

Maintain a
Common
Ground

The maximum bus lengths are based on grounding conditions
typically found in computer room and office environments.
Improper grounding can result in voltage potentials, called ground
offset voltages, between the enclosures in the configuration. If
these voltages exceed certain limits, data transmission across the
DSSI bus can be disrupted, and the configuration can experience
performance degradation or data corruption.
For these reasons, a common ground must be maintained between
all systems and enclosures in a DSSI VMScluster at all times. All
systems must receive their power from a common power feed. It
is not advisable to power systems and enclosures from different
circuit breaker panels.

Verify Site
Conditions

Before you install a DSSI VMScluster system, you should verify
site conditions.
1. A qualified electrician should ensure that site power

distribution meets all local electrical codes.
2. The electrician should inspect the entire site power

distribution system to ensure that it does not have any of the
following faults:

Offset Limits

•

Outlets do not have power ground connections

•

Grounding prong is missing from computer equipment
power cables

•

Power outlet neutral connections are actual ground
connections

•

Grounds for the power outlets are not connected to the
same power distribution panel

•

Devices that are not UL or IEC approved are connected to
the same circuit breaker as the computer equipment

Table 1–2 shows acceptable ground offset limits between cabinets
in a DSSI VMScluster.
Table 1–2 Acceptable Ground Offset Limits by Length of DSSI
Interconnect

Measuring
Grounding
Offset Voltage

DSSI Length

Allowable Offset

Up to 20 m (65.6 ft)

200 mv (DC); 70 mv (AC)

20–25 m (65–82 ft)

40 mv (DC); 14 mv (AC)

You can use a hand-held multimeter to measure the grounding
offset voltage between any two cabinets. Connect the voltmeter
leads to unpainted metal on each enclosure, and compare the
reading you obtain to the acceptable offset values in Table 1–2.

1–6 DSSI VMScluster Configuration and Requirements

DSSI Bus Lengths and Grounding Requirements

The multimeter method provides data only for the moment it is
measured. The ground offset values may change over time as
additional devices are plugged into the same power source or
activated. To ensure that the ground offsets will remain within
acceptable limits over time, you need a power survey by an
electrician.

Install
Grounding
Cables

You should install Digital grounding cables between enclosures.
Digital supplies ground cables with some hardware kits. You can
also order the cables separately (order numbers BC21G-50 and
BC21G-25 for the required number 6 cables; the numbers after
the hyphen refer to the length in feet).

Maximum
Number of
Enclosures

Up to five enclosures can be configured on a DSSI bus:
•

Two systems and up to three expansion enclosures

•

Three systems and up to two expansion enclosures

Recommended Guidelines for DSSI VMScluster Systems
General
Guidelines

The following are recommended guidelines for configuring a DSSI
VMScluster:
•

Whenever possible, DSSI adapters of the same performance
level, measured in I/Os per second, (see Table 1–3) should be
connected on the same DSSI bus to optimize performance.

•

Different types of adapters are allowed in the same system;
whenever possible, connect the same types of adapters on the
same DSSI bus to maximize performance. Refer to Table 1–3
for information on adapter performance and characteristics.

•

Ensure that each DSSI bus is terminated at each end at
all times. Breaking a bus connection or removing a DSSI
terminator while a cluster is operational may lead to data
corruption.

•

Do not configure DSSI VMScluster systems with a power bus.
Inadvertently bringing down the cluster defeats the added
reliability of a DSSI VMScluster.

•

You can add an optional uninterruptible power supply (UPS)
to the VMScluster configuration to increase the level of
availability.

DSSI VMScluster Configuration and Requirements 1–7

Recommended Guidelines for DSSI VMScluster Systems

Table 1–3 provides adapter information for AXP supported
adapters.

DSSI Adapter
Characteristics

Table 1–3 DSSI Adapter Characteristics for AXP Supported Adapters

Adapters

Cluster
Traffic
Middle-Node1
Support Support

I/Os per
Second2

Type

Cluster
Serviceability3

EDA640

Yes

340

Embedded

KFDDA

Yes

1000 x 1

Embedded

Yes

KFDDB

Yes

1000 x 2

Embedded

Yes

KFESA (EISAto-DSSI)

Yes

1000 x 1

EISA-bus

Yes

KFESB (EISAto-DSSI)

Yes

1000 x 1

EISA-bus

Yes

KFMSA

Yes

Yes, BA variant
No, AA variant

800 x 2

XMI

Yes

KFMSB

Yes

Yes, BA variant
No, AA variant

608 x 2

XMI

Yes

KFQSA

With IN/OUT
connectors—Yes
Without IN/OUT
connectors—No

170

Q–bus

With IN/OUT
connectors—
Yes
Without IN
/OUT
connectors—No

N710 (DEC
4000 AXP)

Yes

1200 x 4

Embedded

Yes

SHAC
(KA694,
KA692,
KA691,
KA681,
KA676,)

Yes

Bus 0—No
Bus 1—Yes

1200 x 2

Embedded

Yes

SHAC
(KA670)

Yes

Bus 0—No
Bus 1—Yes

800 x 2

Embedded

Yes

SHAC
(KA53,
KA52)

Yes

With IN/OUT
connectors—Yes
Without IN/OUT
connectors—No

1200 x 2

Embedded

Yes

SHAC
(KA660)

Yes

800

Embedded

1 Middle nodes do not contain embedded DSSI termination, and thus support more than two hosts on their DSSI bus.
2 Throughput is per DSSI bus. Total throughput may be less than the sum.
3 Cluster serviceability refers to the ability to service the adapter without violating DSSI bus termination.

1–8 DSSI VMScluster Configuration and Requirements

2
Installation: AXP-Only or Dual-Architecture
(AXP and VAX) Configurations
In this Chapter

Examples of
Configurations

This chapter describes the hardware steps required to set
up and install a DSSI VMScluster that includes AXP-only or
dual-architecture configurations of KFESA-based AlphaServer
2000/2100 systems or DEC 4000 AXP systems:
•

Step 1: Configure Bus Node IDs for Host Adapters

•

Step 2: Configure Bus Node ID Plugs

•

Step 3: Set HSD05 Array Controller Bus Node ID

•

Step 4: Connect Ground Cables Between Enclosures

•

Step 5: Connect DSSI Cables Between Enclosures

•

Step 6: Set DSSI Device Parameters

•

Step 7: Configure SCSI Node ID Plugs

•

Step 8: Set Boot Parameters

•

Step 9: Complete the Installation

Figure 2–1 shows a sample configuration with two KFESA-based
AlphaServer 2100 systems in a DSSI VMScluster.
Figure 2–2 shows a sample configuration with two DEC 4000 AXP
systems in a DSSI VMScluster.
Figure 2–3 shows a sample dual-architecture DSSI VMScluster
with two KFESA-based AlphaServer 2100 systems and a VAX
4000.
Figure 2–4 shows a sample dual-architecture DSSI VMScluster
with two DEC 4000 AXP systems and a VAX 4000.

Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations 2–1

Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations

Figure 2–1 AXP-Only DSSI VMScluster: Two AlphaServer 2100 Systems
System B

System A
KFESA Host Adapter
Bus Node 7
HSD05 Array Controller
Bus Node 0

KFESA Host Adapter
Bus Node 6
HSD05 Array Controller
Bus Node 1

4
1
5
2
6
3

Front

Rear
BC29S-xx

4
1
5
2
6
3

Front

Rear
BC29S-xx
BC29S-xx

MA071493

Figure 2–2 AXP-Only DSSI VMScluster: Two DEC 4000 Systems
System A

System B

DEC 4000 AXP

5 4
5 4 3 2

5 4 32
1

Host
Bus Node 7

Host
Bus Node 6

3 2 1 0
5

Host
Bus Node 6

3 2 1 0 10

Host
Bus Node 6

1 0

Host
Bus Node 6

Shared DSSI Buses and Devices
MLO-010630

2–2 Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations

Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations

Figure 2–3 Dual-Architecture DSSI VMScluster: AlphaServer 2100 Systems and VAX 4000
Systems
System B

System A

KFESA Host Adapter
Bus Node 6

KFESA Host Adapter
Bus Node 7
HSD05 Array Controller
Bus Node 0
Terminator

BC29S-xx
HSD05 Array Controller
Bus Node 1

4
1
5
2
6
3

Front

Rear
BC29S-xx

4
1
5
2
6
3

Front

Rear
BC29S-xx

System C
VAX 4000-300 or Higher

RX400X Expander
BC29R-xx

Terminator

Host
Bus Node 5
Terminator
BC21M-09

Host Bus Node 7
MA071593

Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations 2–3

Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations

Figure 2–4 Dual-Architecture DSSI VMScluster: DEC 4000 Systems and VAX 4000 System
System A

System C

DEC 4000 AXP

5 4

5 4 3 2

4 3 32

Host
Bus Node 6

Host
Bus Node 7

3 2 1 0
5

Host
Bus Node 7

2 1 0 10

Host
Bus Node 7

1 0

Host
Bus Node 7

System B
VAX 4000-300 or Higher

R400X Expander

Host
Bus
Node 7

Host
Bus
Node 5

Terminator

Shared DSSI Buses and Devices
MLO-010631

2–4 Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations

Step 1: Configure Bus Node IDs for Host Adapters

Step 1: Configure Bus Node IDs for Host Adapters
DSSI Adapter
Bus Node IDs

By convention, host adapters in a two-system DSSI VMScluster
are assigned bus node IDs 6 and 7; in a three-system DSSI
VMScluster they are assigned 5, 6, and 7; and in a four-system
DSSI VMScluster, 4, 5, 6, and 7.

KFESA Adapter
IDs

AlphaServer 2000/2100 systems use the KFESA DSSI host
adapter. The bus node ID (or device ID) for the KFESA is
changed using the EISA Configuration Utility (ECU).

DEC 4000 AXP
Adapter IDs

DEC 4000 AXP systems use embedded DSSI host adapters.
The bus node ID (or device ID) for DEC 4000 AXP adapters are
changed by setting the NCRn_SETUP environment variables.

HSD30 Array
Controllers

Each HSD30 array controller counts as one DSSI node. The
DSSI bus node ID for these controllers is set using the set
this_controller ID=n and set other_controller ID=n from the
HSD30 maintenance terminal.

KFMSB
Adapter

DEC 7000/10000 AXP systems use the KFMSB host adapter. The
bus node ID (or device ID) for KFMSB adapters is changed using
the modify command through the Loadable Firmware Update
Utility (LFU).

Changing the KFESA Adapter Bus Node ID (AlphaServer
2000/2100 Systems)
Running the
ECU

Run the ECU as follows to change the KFESA host bus node ID:
1. Start the ECU according to the instructions provided with

your system documentation.
2. After the ECU copyright is displayed, the ECU loads the

configuration file for the KFESA. If the file is not included on
the ECU diskette, the ECU program prompts you to insert the
configuration diskette for the option.
While the configuration files are loading, the ECU displays the
message:
Loading configuration files
Please wait...

Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations 2–5

Changing the KFESA Adapter Bus Node ID (AlphaServer 2000/2100 Systems)

When the files have finished loading, a menu similar to the
following is displayed:
EISA Configuration Utility
Steps in configuring your computer
STEP 1: Important EISA configuration Information
STEP 2: Add or remove boards
STEP 3: View or edit details
STEP 4: Examine required details
STEP 5: Save and exit
>Select=ENTER< <Cancel=ESC>
3. Select the ‘‘View or edit details option’’ (Step 3 in the example

below) and press the Enter key. Scroll through the file until
you find the KFESA option and its slot number. The display
lists the current settings. A sample file is shown below:
Step 3: View or edit details
Slot 7 -- Digital KFESA DSSI EISA Host Adapter

Added

Host Adapter Interface...................Trigger EDGE
Host Adapter IRQ.........................IRQ 15
Host Adapter DSSI ID.....................Device ID 7
To change the bus node ID setting (edit details), select the
‘‘Host Adapter DSSI ID’’ function or setting and press the
Return key.
Note

Never set a host adapter IRQ of 9.
When you have finished with the option settings, press F10. A
main menu similar to the following is displayed:
EISA Configuration Utility
Steps in configuring your computer
STEP 1: Important EISA configuration Information
STEP 2: Add or remove boards
STEP 3: View or edit details
STEP 4: Examine required details
STEP 5: Save and exit
>Select=ENTER< <Cancel=ESC>

2–6 Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations

Changing the KFESA Adapter Bus Node ID (AlphaServer 2000/2100 Systems)

4. Select ‘‘Save and exit’’ (Step 5 in the example above) and press

the Enter key. A screen will verify that you want to save the
configuration and a screen similar to the following is then
displayed:
EISA Configuration Utility
Your configuration file has been saved, and if possible a backup SYSTEM.SCI file
has been made on the current drive.
To complete your configuration, you must do one of the following:
If you need to install boards or change switches and jumpers on boards already
installed, turn off your computer and do so.
If you want to test your system or install an operating system, press ENTER to
restart your computer, run the configuration utility again, and select the appr
main menu item.
If you are finished configuring, remove the SYSTEM CONFIGURATION diskette if
it is in drive A and press ENTER to restart your system.
Ok=ENTER
Follow the directions on the screen displays until you have
saved and exited the ECU.
5. Return to your system documentation for instructions on

returning to the SRM console, which supports OpenVMS.

Turn Off
System Power

After setting the KFESA host adapter bus node numbers, turn off
system power by setting the DC On/Off switch to off.

Changing NCRn_SETUP Environment Variables (DEC 4000 AXP
Systems)
Set Bus Mode
and Bus Node
Numbers

For each DEC 4000 AXP host adapter that supports DSSI devices,
set the bus mode to ‘‘DSSI.’’

Use
NCRn_SETUP
Environment
Variables

In DEC 4000 AXP systems, you change the bus mode and
bus node numbers for host adapters by setting NCRn_SETUP
environment variables.

In addition, for DSSI VMScluster systems with two DEC 4000
AXP systems, change one of the system’s bus node numbers for
the host adapters to be shared. For each host adapter to be
shared, set the bus node number to 6.

Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations 2–7

Changing NCRn_SETUP Environment Variables (DEC 4000 AXP Systems)

Note

When diskless DSSI buses are to be shared (for increased
performance and redundancy), you still need to set the
bus mode to DSSI, and change the host adapter bus node
numbers accordingly.

Host Adapters
and Bus
Locations

Table 2–1 shows the relationship of the NCRn_SETUP
environment variables to the DEC 4000 AXP storage buses.
Table 2–1 Host Adapters for DEC 4000 AXP Systems

Example: Set
NCRn_SETUP
Variables

Host Adapters

Storage Bus

Location

NCR0_
SETUP

0 (or A in console
mode)

Top drawer

NCR1_
SETUP

1 (or B in console
mode)

Second drawer

NCR2_
SETUP

2 (or C in console
mode)

Third drawer

NCR3_
SETUP

3 (or D in console
mode)

Bottom drawer

NCR4_
SETUP

4 (or E in console
mode)

Removable-media storage
compartment (SCSI only)

In the following example, all four DSSI host adapters in Systems
A and B are assigned a bus mode of DSSI. All four DSSI host
adapters in System B are assigned a bus node number of 6.
# For System A
>>> show ncr*
ncr0_setup
AUTO 7
ncr1_setup
AUTO 7
ncr2_setup
AUTO 7
ncr3_setup
AUTO 7
ncr4_setup
AUTO 7
>>> set ncr0_setup "DSSI 7"
>>> set ncr1_setup "DSSI 7"
>>> set ncr2_setup "DSSI 7"
>>> set ncr3_setup "DSSI 7"
>>> show ncr*
ncr0_setup
DSSI 7
ncr1_setup
DSSI 7
ncr2_setup
DSSI 7
ncr3_setup
DSSI 7
ncr4_setup
AUTO 7
>>>

2–8 Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations

Changing NCRn_SETUP Environment Variables (DEC 4000 AXP Systems)

# For System B
>>> show ncr*
ncr0_setup
AUTO 7
ncr1_setup
AUTO 7
ncr2_setup
AUTO 7
ncr3_setup
AUTO 7
ncr4_setup
AUTO 7
>>> set ncr0_setup "DSSI 6"
>>> set ncr1_setup "DSSI 6"
>>> set ncr2_setup "DSSI 6"
>>> set ncr3_setup "DSSI 6"
>>> show ncr*
ncr0_setup
DSSI 6
ncr1_setup
DSSI 6
ncr2_setup
DSSI 6
ncr3_setup
DSSI 6
ncr4_setup
AUTO 7
>>>

Turn Off
System Power

After setting the host adapter bus node numbers and specifying
the bus mode, turn off system power by setting the DC On/Off
switch to off.

Changing the HSD30 Array Controller Bus Node IDs
Set
this_controller
ID; Set
other_controller
ID

Each HSD30 array controller counts as one DSSI node. If your
configuration includes an HSD30 array controller, be sure that its
controllers are assigned a unique bus node ID. DSSI nodes for the
HSD30 are changed using the set this_controller ID=n and set
other_controller ID=n commands from the HSD30 maintenance
terminal.
Refer to the StorageWorks Array Controllers HS Family of Array
Controllers User’s Guide, EK-HSFAM-UG.

HSD30
Example

In the following example, one of the HSD30 array controllers
is assigned a bus node ID of 7 from the HSD30 maintenance
terminal.

Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations 2–9

Changing the HSD30 Array Controller Bus Node IDs

CLI -> set this_controller id=7
Warning 4000: A restart of this controller will be required
before all the parameters modified will take effect
Restart of this controller required
CLI -> show this_controller
Controller:
HSD30 ZG33400081 Software V14D, Hardware 0000
Configured for dual-redundancy with ZG33400048
In dual-redundant configuration
SCSI address 7
Host port:
Node name: VINCE, valid DSSI node 7
Host path is ON
MSCP allocation class
5
TMSCP allocation class 5
Cache:
No cache
Restart of this controller required
CLI ->

Changing the KFMSB Host Adapter Bus Node IDs
Loadable
Firmware
Update Utility

DEC 7000/1000 AXP systems use the KFMSB adapter. Each
KFMSB provides two DSSI busses, each with a factory setting
of bus node ID 7. The bus node ID (or device ID) for KFMSB
adapters is changed using the modify command through the
Loadable Firmware Update Utility (LFU).
Refer to the KFMSB Adapter Installation Guide, EK-KFMSB-IN.

2–10 Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations

Step 2: Configure Bus Node ID Plugs

Step 2: Configure Bus Node ID Plugs
Unique Bus
Node ID Plugs

Configure bus node ID plugs so that all DSSI devices on a shared
bus (mass storage and host adapters) have unique bus node
numbers.
DSSI storage devices have bus node ID plugs to provide a DSSI
node number for the device. VAX 4000 systems use bus node
ID plugs to supply DSSI node numbers for their embedded host
adapters. Depending on the number of systems in the cluster, set
VAX 4000 host adapters to 6 or 5.

Step 3: Set HSD05 Array Controller Bus Node ID
HSD05 Bus
Node ID

Each HSD05 array controller counts as one DSSI node. If your
configuration includes HSD05 array controllers, be sure that the
HSD05 is assigned a unique DSSI bus node ID. DSSI node IDs for
the HSD05 are set by switches on the HSD05 controller module
board (switches 1, 2, and 3, with 3 being the least significant bit).
The factory default setting is 0.
Refer to the StorageWorks Solutions HSD05 Array Controller
User’s Guide, EK-HSD05-UG, for information on switchpack
settings.

Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations 2–11

Step 4: Connect Ground Cables Between Enclosures

Step 4: Connect Ground Cables Between Enclosures
Daisy Chain
Ground Cables

Attach a number 6 gauge ground cable to the ground terminal on
the system power supply. Ground cables should be daisy chained
for systems with multiple enclosures.
Caution

Do not attach more than two ground cables per ground
terminal.

Step 5: Connect DSSI Cables Between Enclosures
DSSI
Connectors
and Cables

Figure 2–5 shows the MR (midrange or micro ribbon) and PS
(pedestal style or pin socket) DSSI connectors. Appendix A
provides the connector type for each enclosure and DSSI adapter.
Table 2–2 lists the cable variants used with DSSI VMSclusters.
Refer to the Digital Systems and Options Catalog for a complete
listing of the latest cable order numbers.

Figure 2–5 Midrange and Pedestal Style DSSI Connectors
Midrange or Micro Ribbon
Style Connector

Pedestal or Pin Socket
Style Connector

MLO-007465

2–12 Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations

Step 5: Connect DSSI Cables Between Enclosures

Table 2–2 DSSI Cable Variations
Cable

Type

BC21M-09

A micro-ribbon cable with two right-angle 50-pin pin socket connectors.
Used to connect:
VAX 4000 systems to R400X expanders
VAX 4000 systems to VAX 4000 systems
R400X expanders to R400X expanders
DEC 4000 systems to R400X expanders
DEC 4000 systems to VAX 4000 systems

BC21Q-xx

A micro-ribbon cable with two straight 50-pin micro-ribbon connectors.
Used to connect:
KFESA adapter to KFESA adapter

BC22Q-xx

A micro-ribbon cable with one right-angle 50-pin pin-socket connector
and one straight 50-pin micro-ribbon connector. Used to connect:
VAX 3000/4000 systems to TF857/SF100

BC29R-xx

A micro-ribbon cable with one right-angle 50-pin pin-socket connector
and one right-angle 50-pin micro-ribbon connector. Used to connect:
HSD05 array controller to DEC 4000 systems
HSD05 array controller to VAX 3000/4000 systems

BC29S-xx

A micro-ribbon cable with one right-angle 50-pin micro-ribbon
connector and one straight 50-pin micro-ribbon connector. Used to
connect:
KFESA host adapter to HSD05 array controller
HSD05 array controller to KFMSB adapter
HSD05 array controller to VAX 6000/7000/10000 systems

BC29U-02

A micro-ribbon cable with two right-angle 50-pin micro-ribbon
connectors mounted facing opposite directions. Used to connect:
HSD05 array controller to HSD05 array controller (within same BA740
enclosure (AlphaServer 2100 systems))

Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations 2–13

Step 5: Connect DSSI Cables Between Enclosures

Check Devices
on the
Configuration
Display

After connecting the DSSI cables, power up the system. Check
the system configuration display using the show config command
to see if there are any missing drives. If drives are missing, check
that bus node IDs are unique for each:
•

DSSI host adapter

•

HSD05 array controller

•

HSD30 array controller

•

DSSI storage device
Note

If you change the bus node ID plugs, you must recycle
power (press the Reset button or turn on power with the
DC On/Off switch) before the new setting will take effect.
The system reads the bus node ID values at power-up.

Step 6: Set DSSI Device Parameters
DSSI Device
Parameters

In creating a DSSI VMScluster system, you need to set DSSI
device parameters according to your configuration:
•

ALLCLASS — In a DSSI VMScluster, each device to be
served to the cluster must have a nonzero allocation class that
matches the allocation class of the system. Each system on
a shared DSSI bus must have the same OpenVMS allocation
class (ALLOCLASS).
Note

For devices connected through early versions of the HSD05
array controllers, this parameter is called DISK_ALCS.

•

UNITNUM — Systems using multiple DSSI buses, as
described in Appendix B, require that the default values
for DSSI storage devices (supplied by bus node ID plugs) be
replaced with unique unit numbers.
Note

Devices connected through the HSD05 and HSD30
array controllers are automatically assigned unique unit
numbers.

2–14 Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations

Step 6: Set DSSI Device Parameters

•

For More
Parameters
cdp Console
Command

NODENAME — You can provide your own node names for
drives; you can use the factory-supplied node names; or you
can use the cdp console command to supply node names that
relate to the device name conventions for AXP systems.

For more information on DSSI parameters and their functions,
refer to Appendix B and VMScluster Systems for OpenVMS.
Caution

The HSD05 and HSD30 array controllers do not currently
support the cdp command. If your configuration includes
the HSD05 or HSD30 controller, do not use the cdp
command. Doing so causes the console subsystem to hang
and requires that you press the Reset button to return to
the console prompt.
•

For systems configured with an HSD05 array controller,
use the set host -dup -dssi device_name command to set
and examine DSSI parameters using the Diagnostic
and Utility Program (DUP).
For examples of the set host -dup -dssi command, see
the section ‘‘set host -dup -dssi Command.’’

•

For systems configured with the HSD30 array
controller, use the set this_controller and set
other_controller commands from the HSD30
maintenance terminal to set and examine device
parameters.
For more information, refer to the StorageWorks
Solutions HSD05 Array Controller User’s Guide,
EK-HSD05-UG and StorageWorks Array Controllers
HS Family of Array Controllers User’s Guide,
EK-HSFAM-UG.

The AXP console command cdp allows you to modify the
NODENAME, ALLCLASS, and UNITNUM parameters. The cdp
command automatically connects to the device’s DUP server for
all devices or any number of specified devices.
Note

When a DSSI bus is shared with a VAX system, the cdp
console command can connect to all the shared drives, even
though they physically reside in the VAX enclosure (or
expansion enclosure).

Enter the cdp command without an option or target device to list
the DSSI parameters for all DSSI drives on the system.

Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations 2–15

Step 6: Set DSSI Device Parameters

Command
Description

cdp ([-{i,n,a,u,o}] [-sn] [-sa allclass] [-su unitnum] [dssi_device])
Arguments:
[dssi_
device]

Name of the DSSI device or DSSI adapter. Only
the parameters for the specified device or devices
on this adapter will be modified.

Options:

DSSI
Parameters
Displayed
Using cdp

[-i]

Selective interactive mode, set all parameters.

[-n]

Set device node name, NODENAME (alphanumeric,
up to 6 characters).

[-a]

Set device allocation class, ALLCLASS.

[-u]

Set device unit number, UNITNUM.

[-sn]

Set node name (NODENAME) for all DSSI drives
on the system to either RFhscn or TFhscn, where:
h is the device hose number (0)
s is the device slot number (0–3)
c is the device channel number (0)
n is the bus node ID (0–6).

[-sa]

Set ALLCLASS for all DSSI devices on the system
to a specified value.

[-su]

Specify a starting unit number for a device on the
system. The unit number for subsequent DSSI
devices will be incremented (by 1) from the starting
unit number.

A sample display of DSSI device information using the cdp
command is shown below:
>>> cdp

pua0.0.0.0.0
pua0.1.0.0.0
pua0.2.0.0.0
pua0.3.0.0.0
pua0.4.0.0.0
pua0.5.0.0.0
>>>

ALPHA0
ALPHA1
ALPHA2
ALPHA3
ALPHA4
ALPHA5

0411214901371
0411214901506
041122A001625
0411214901286
0411224904506
0411233087412

2
2
2
2
2
2

$2$DIA0
$2$DIA1
$2$DIA2
$2$DIA3
$2$DIA4
$2$DIA5

0
1
2
3
4
5

! Storage adapter device name
" Node name (NODENAME)
# System ID (SYSTEMID) — modified during warm swap
$ Allocation class (ALLCLASS)
% Unit number (UNITNUM)
& Operating system device name

2–16 Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations

Step 6: Set DSSI Device Parameters

cdp Example

In the following sample display, which corresponds to the
configuration shown in Figure 2–2:
•

The unit numbers for drives on DSSI buses B, C, and D are
changed to avoid duplicate unit numbers. Bus B is given unit
numbers starting with 10; Bus C starting with 20; and Bus D
starting with 30.

•

The allocation class for all drives is changed to 1.

•

Drive dub0 is given the new node name, SYSTEM.

>>> cdp -sa 1
pua0.0.0.0.0
ALPHA0
0411214901371
pua0.1.0.0.0
ALPHA1
0411214901506
pua0.2.0.0.0
ALPHA2
041122A001625
pua0.3.0.0.0
ALPHA3
0411214901286
pua0.4.0.0.0
ALPHA4
0411224904506
pua0.5.0.0.0
ALPHA5
0411233087412
>>> cdp -sa 1 -su 10 dub
pub0.0.0.1.0
SNEEZY
0411214906794
pub1.1.0.1.0
DOPEY
0411214457623
pub2.2.0.1.0
SLEEPY
0478512447890
pub3.3.0.1.0
GRUMPY
0571292500565
pub4.4.0.1.0
BASHFL
0768443122700
pub5.5.0.1.0
HAPPY
0768443122259
>>> cdp -sa 1 -su 20 duc
puc0.0.0.2.0
RF0200
0347500845133
puc1.1.0.2.0
RF0201
0889734564411
puc2.2.0.2.0
RF0202
0411780351455
puc3.3.0.2.0
RF0203
0555613903222
puc4.4.0.2.0
RF0204
0744673884100
puc5.5.0.2.0
RF0205
0298438401226
>>> cdp -sa 1 -su 30 dud
pud0.0.0.3.0
RF0300
0620707250334
pud1.1.0.3.0
RF0301
0889734564411
>>> cdp -n dub0
pub0.0.0.1.0:
Node Name [SNEEZY]? SYSTEM
>>>

set host
-dup -dssi
Command
(HSD05/HDS30)

1
1
1
1
1
1

0
1
2
3
4
5

$1$DIA0
$1$DIA1
$1$DIA2
$1$DIA3
$1$DIA4
$1$DIA5

1
1
1
1
1
1

10
11
12
13
14
15

$1$DIA10
$1$DIA11
$1$DIA12
$1$DIA13
$1$DIA14
$1$DIA1

1
1
1
1
1
1

20
21
22
23
24
25

$1$DIA20
$1$DIA21
$1$DIA22
$1$DIA23
$1$DIA24
$1$DIA25

1 30 $1$DIA30
1 31 $1$DIA31

The set host -dup -dssi device_name command is used in place of
the cdp command for systems using the HSD05 and HSD30 array
controllers. This command allows you to enter the DUP server
utility for a specified device. Through the DUP server utility, you
can set and examine DSSI parameters for the specified device.

Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations 2–17

Step 6: Set DSSI Device Parameters

Starting DUP:
Example

>>> set host -dup -dssi dub34
starting DIRECT on pub0.3.0.3.1 (HSD05A)
Copyright 1994 Digital
HSD05
Serial No: 2033
Firmware Rev. B1 (X36A)
DIRECT V1.0 D Mar 21 1994 17:09:41
PARAMS V1.0 D Mar 21 1994 17:09:41
UTILIT V1.0 D Mar 21 1994 17:09:41
End of directory
Task? params
starting PARAMS on pub0.3.0.3.1 (HSD05A)
Copyright 1994 Digital
HSD05
Serial No: 2033
Firmware Rev. B1 (X36A)
PARAMS>

Setting
Allocation
Class

After entering the DUP server utility for a specified device, you
can examine and set the allocation class for the device as follows.
Note

Set the ALLCLASS parameter only through console
mode, at the PARAMS> prompt. Setting the ALLCLASS
parameter from the operating system is not recommended.
Devices connected through early versions of the HSD05
array controller use the parameter DISK_ALCS for
allocation class; all other DSSI devices use the parameter
ALLCLASS.

1. At the PARAMS> prompt, enter show allclass (or show

disk_alcs for HSD05 devices) to check the allocation class of
the device to which you are currently connected.
2. Enter set allclass 1 (or enter the allocation class you desire).
3. Enter show allclass to verify the new allocation class.

The following example shows the steps for examining and
changing the allocation class for a specified device. In the
example, the allocation class is changed from class 0 to class 1 for
a device connected through an HSD05.
PARAMS> show disk_alcs
DISK_ALCS
PARAMS> set disk_alcs 1

255

DecimalNum

255

DecimalNum

PARAMS> show disk_alcs
DISK_ALCS

2–18 Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations

Step 6: Set DSSI Device Parameters

Setting Unit
Number

After entering the DUP server utility for a specified device, you
can examine and set the unit number for the device as follows.
Note

The HSD05 and HSD30 array controllers automatically
provide unique unit numbers for its drives. For devices
connected through the HSD05 and HSD30 controllers, you
do not usually need to change this parameter.

1. At the PARAMS> prompt, enter show unitnum to check the unit

number of the device to which you are currently connected.
2. Enter set unitnum 10 (or enter the unit number you desire).
3. Enter set forceuni 0 to override the default unit number value

supplied by the bus node ID plug.
4. Enter show unitnum to verify the new unit number.
5. Enter show forceuni to verify that the current value for the

FORCEUNI parameter is 0.
6. Label the device with its unit number, using the unit number

labels shipped with your system.
The following example shows the commands for changing the unit
number of a specified device from number 0 to number 10.
PARAMS>show unitnum
Parameter
Current
Default
Type
Radix
--------- ---------------- ---------------- -------- ----UNITNUM
0
0
Word
Dec

PARAMS>set unitnum 10
PARAMS>set forceuni 0
PARAMS>show unitnum
Parameter
Current
Default
Type
Radix
--------- ---------------- ---------------- -------- ----UNITNUM
10
0
Word
Dec

PARAMS>show forceuni
Parameter
Current
Default
Type
Radix
--------- ---------------- ---------------- -------- ----FORCEUNI
0
1 Boolean
0/1

Setting Node
Name

After entering the DUP server utility for a specified device, you
can examine and set the node name for the device as follows.
1. At the PARAMS> prompt, enter show nodename to check the

node name of the device to which you are currently connected.
2. Enter set nodename sysdsk (or enter the desired alphanumeric

node name of up to eight characters).
3. Enter show nodename to verify the new node name.

Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations 2–19

Step 6: Set DSSI Device Parameters

The following example shows the commands for changing the
node name of a specified device from the factory-supplied name to
SYSDSK.
PARAMS>show nodename
Parameter
Current
Default
Type
Radix
--------- ---------------- ---------------- -------- ----NODENAME
R7CZZC
RZ35
String Ascii

PARAMS>set nodename sysdsk
PARAMS>show nodename
Parameter
Current
Default
Type
Radix
--------- ---------------- ---------------- -------- ----NODENAME
SYSDSK
RZ35
String Ascii

Exiting the
DUP Server
Utility

After you have finished setting and examining DSSI device
parameters for a specified device, enter the write command at
the PARAMS> prompt to save the device parameters you have
changed using the SET command. The changes are recorded to
nonvolatile memory.
Note

If you have set host to devices connected through the
HSD05 array controller, you must enter recycle system
power—shut of the system and then turn it back on—for
the new parameters to take effect.

•

If you have changed the allocation class or node name of a
device, the DUP server utility will ask you to initialize the
controller. Answer Yes (Y) to allow the changes to be recorded
and to exit the DUP server utility.
PARAMS>write
Changes require controller initialization, ok? [Y/(N)] Y
Stopping DUP server...
>>>

•

If you have not changed the allocation class or node name,
enter the exit command at the PARAMS> prompt to exit the
DUP server utility for the specified device.
Note

You must repeat the procedures in this step for each device
for which you want to change parameters.

2–20 Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations

Step 7: Configure SCSI Node ID Plugs

Step 7: Configure SCSI Node ID Plugs
When to
Change SCSI
Node Plugs

If systems in a DSSI VMScluster contain SCSI drives, configure
SCSI node ID plugs or SCSI node ID switch settings so that
OpenVMS sees each SCSI device name as unique.
To determine if you need to change SCSI node ID plugs, consider
these points:

Example with
Conflicting
SCSI Device
Names

•

For each system, the OpenVMS operating system ‘‘names’’ the
first SCSI bus it finds as bus A, the second SCSI bus as bus B,
and so on.

•

All SCSI drives in the DSSI VMScluster are forced to the
allocation class of the host systems.

Figure 2–6 and Table 2–3 show a sample configuration that calls
for changing SCSI node ID plugs to avoid duplicate device names.
Note

SCSI unit numbers are forced to 100 x node ID (ID plug).

Example with
Unique SCSI
Device Names

To avoid the problem of duplicate SCSI device names, shown in
Table 2–3, change the SCSI node ID switch settings for the SCSI
drives on System A.
Table 2–4 shows how the devices are uniquely named after you
change the SCSI node ID switches for the SCSI devices. The
SCSI disks in System A are given node ID settings of 0, 1, and
the host SCSI ID is set to 6.
Note that in this example, the node ID for the SCSI host adapter
in System A is changed from the default (7) to 6. This allows up
to eight SCSI devices to be configured on the SCSI bus, each with
a unique SCSI node ID (0–7).
The following commands are used to set SCSI host adapter node
IDs:

System

Command

AlphaServer
2000/2100

set pk*_host_id node_ID

DEC 4000 AXP

set ncr*_setup "SCSI node_ID"

VAX 4000
Model 100A/100

SET SCSI_ID bus_number node_ID

Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations 2–21

Step 7: Configure SCSI Node ID Plugs

Figure 2–6 Configuration with Duplicate SCSI Device Names
System B

System A
SCSI Node 6

SCSI Node 6

SCSI Node 5

Front

Rear
Front

Rear

MA071693

Table 2–3 Configuration with Conflicting SCSI Device Names
System A
SCSI
Node Console Mode
ID
Device Name

OpenVMS Device Name

MKA500

$1$MKA5003

DKA600

$1$DKA6003

System B

MKA500

$1$MKA5003

DKA600

$1$DKA6003

3 Duplicate SCSI device name

2–22 Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations

Step 7: Configure SCSI Node ID Plugs

Table 2–4 Configuration with Unique SCSI Device Names
System A
SCSI
Node Console Mode
ID
Device Name

OpenVMS Device Name

MKA0

$1$MKA01

DKA100

$1$DKA100

Host adapter

System B

MKA500

$1$MKA500

DKA600

$1$DKA600

Host adapter

1 In this example, the allocation class is 1.

Note

For each SCSI bus that the OpenVMS operating system
sees as common to both systems, the total number of drives
is limited to eight (node IDs 0–7).

Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations 2–23

Step 8: Set Boot Parameters

Step 8: Set Boot Parameters
Set the boot parameters for booting on each system.

Boot
Parameters

Table 2–5 lists the boot environment variables and their related
boot parameters.

Table 2–5 Boot Parameters for AXP and VAX Systems
AXP Console Boot Parameters

>>> set bootdef_dev dua0

Sets the device or device list from which booting is to be
attempted. In this example, dua0 is specified as the boot
device.

>>> set boot_osflags 0,0

Sets additional parameters (root number and boot flags)
to be passed to the system software during booting if none
are specified. In this example, system root 0 [SYS0] with 0
as the boot flag mask.

>>> set boot_osflags 0,1

Sets additional parameters (root number and boot flags)
to be passed to the system software during booting if
none are specified. In this case the system will stop at
SYSBOOT.

>>> set boot_osflags 1,0

Sets additional parameters (root number and boot flags)
to be passed to the system software during booting if
none are specified. In this case the system boots from the
system root [SYS1] rather than [SYS0].

VAX Console Boot Parameters

>>> set boot dua0

Sets the device or device list from which booting is to be
attempted. In this example, dua0 is specified as the boot
device.

>>> set bflag 0

Sets additional parameters to be passed to the system
software during booting if none are specified. In this
example, system root 0 [SYS0].

>>> set bflag 1

Sets additional parameters to be passed to the system
software during booting if none are specified. In this case
the system will stop at SYSBOOT.

>>> set bflag 10000000

Sets additional parameters to be passed to the system
software during booting if none are specified. In this case
the system boots from the system root [SYS1] as opposed
to [SYS0].

2–24 Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations

Step 8: Set Boot Parameters

Boot Parameter
Examples

AXP Only Example

In the following example, boot parameters are set for two AXP
systems in a DSSI VMScluster:
# For system A
>>> set boot_osflags 0,0
>>> set bootdef_dev dua0
>>> boot
# For system B
>>> set boot_osflags 1,0
>>> set bootdef_dev dua0
>>> boot
Dual-Architecture Example

In the following example, boot parameters are set for a
dual-architecture DSSI VMScluster:
# For system A (AXP System)
>>> set boot_osflags 0,0
>>> set bootdef_dev dub10
>>> boot
# For system B (VAX System)
>>> set bflag 10000000
>>> set boot dua0
>>> boot
Note

In a dual-architecture configuration, the AXP system and
the VAX system cannot boot from a common disk.

Step 9: Complete the Installation
Complete the software steps of the DSSI VMScluster installation,
such as updating the cluster_config.com file. Refer to the
information provided in Factory Installed Software User
Information or OpenVMS AXP Version 6.1 Upgrade and
Installation Manual and VMScluster Systems for OpenVMS.

Installation: AXP-Only or Dual-Architecture (AXP and VAX) Configurations 2–25

3
Installation: VAX-Only Configuration
In This Chapter

Examples of
Configurations

This chapter describes the hardware steps required to set up and
install a VAX-only DSSI VMScluster:
•

Step 1: Configure Bus Node IDs for Host Adapters and Mass
Storage Devices

•

Step 2: Connect Ground Cables Between Enclosures

•

Step 3: Connect DSSI Cables Between Enclosures

•

Step 4: Set DSSI Device Parameters

•

Step 5: Configure SCSI Node IDs

•

Step 6: Set Boot Parameters

•

Step 7: Complete the Installation

Figure 3–1 shows a sample expanded two-system DSSI
VMScluster configuration. The schematic representation shows
the path of each DSSI bus, the node numbers for each storage
device and host adapter, and the unit numbers for each storage
device.

Installation: VAX-Only Configuration 3–1

Figure 3–1 Expanded Two-System DSSI VMScluster
Bus Node ID
Locations

Expander
System A

2 1 0

3 2 1

Bus Node ID
Plug 6

6 5 4

Bus Node ID
Plug 6

DSSI
Terminator
Locations

System B

5 4 3
Bus Node ID
Plug 7
Bus Node ID
Plug 7

DSSI
Terminator
Locations

2
1

3
2

4
3

5
4

System A
SHAC
Bus Node 6

System B
SHAC
Bus Node 7

KAnn

SHAC
Bus Node 7

SHAC
Bus Node 6

System A

System B

Bus Node Number
Unit Number

DSSI Bus Nodes for Storage Devices in Expander
DSSI Bus Nodes for Storage Devices in System A and System B
MLO-008663

3–2 Installation: VAX-Only Configuration

Step 1: Configure Bus Node IDs for Host Adapters and Mass
Storage Devices
Unique Bus
Node ID Plugs

Configure bus node ID plugs for each mass storage device so
that all DSSI devices on a shared bus (mass storage and host
adapters) have unique bus node numbers.

Host Adapters

Often when a DSSI is shared between systems, it will be
necessary to change the bus node number for at least one host
adapter from the default setting since each bus node on the same
bus must be unique.
By convention, host adapters on a DSSI shared between two
systems are assigned 6 and 7; 5, 6, and 7 are assigned on a DSSI
shared among three systems; and 4, 5, 6, and 7 are shared among
four systems.
VAX 4000 systems use bus node ID plugs to select bus node
numbers for the host adapters 0 and 1. These same ID plugs
also provide the default bus node numbers for buses 2 and 3 for
VAX 4000 Model 500A/505A/600A/700A/ 705A systems using the
KFDDB option.
The SET DSSI_ID firmware command is used to override the
default settings for buses 2 and 3 (above), as well as to change
the settings for buses 0 and 1 on VAX 4000 Model 100A\105A
systems using the KFDDA option.

SET DSSI_ID
and SHOW
DSSI_ID
Commands

The firmware commands SET DSSI_ID and SHOW DSSI_ID allow you
to override default bus node setting for onboard host adapters.
Note that these firmware commands are available only on KA52,
KA53, KA681, KA691, KA692, and KA694 CPUs.

Command

Function

SET DSSI_ID bus_number
bus_node

Use this command to override the default bus node
numbers for a specified host adapter. Assigning a value
of F for bus_node returns the default determined by the
bus node ID plug. These values are stored in nonvolatile
FEPROM.
Displays the current bus node settings for the onboard
(SHAC) host adapters.

SHOW DSSI_ID

Installation: VAX-Only Configuration 3–3

Step 1: Configure Bus Node IDs for Host Adapters and Mass Storage Devices

SET DSSI_ID
Example
>>>SHOW DSSI_ID
DSSI_ID Bus 0/A = 7
DSSI_ID Bus 1/B = 6
DSSI_ID Bus 2/C = 7
DSSI_ID Bus 3/D = 6
>>>SET DSSI_ID 2 6
>>>SET DSSI_ID 3 5
>>>SHOW DSSI_ID

determined by Bus 0 ID Plug
determined by Bus 1 ID Plug
determined by Bus 0 ID Plug
determined by Bus 1 ID Plug

DSSI_ID Bus 0/A = 7
DSSI_ID Bus 1/B = 6
DSSI_ID Bus 2/C = 6
DSSI_ID Bus 3/D = 5
>>>

determined by Bus 0 ID Plug
determined by Bus 1 ID Plug
determined by SET DSSI_ID command, bus 0 ID Plug ignored
determined by SET DSSI_ID command, bus 1 ID Plug ignored
Note

When diskless DSSI buses are to be shared (for increased
performance and redundancy), you still need to ensure that
the host adapter bus node numbers are unique.

HSD30 Array
Controllers

3–4 Installation: VAX-Only Configuration

Step 1: Configure Bus Node IDs for Host Adapters and Mass Storage Devices

HSD30
Example

In the following example, one of the HSD30 controllers is assigned
a bus node ID of 7 from the the HSD30 maintenance terminal.

CLI -> set this_controller id=7
Warning 4000: A restart of this controller will be required before all the
parameters modified will take effect
Restart of this controller required
CLI ->show this_controller
Controller:
HSD30 ZG33400081 Software V14D, Hardware 0000
HSD30 ZG33400081 Software V14D, Hardware 0000
Configured for dual-redundancy with ZG33400048
In dual-redundant configuration
SCSI address 7
Host port:
Node name: VINCE, valid DSSI node 7
Host path is ON
MSCP allocation class
5
TMSCP allocation class 5
Cache:
No cache
Restart of this controller required
CLI ->

HSD05 Bus
Node ID

Each HSD05 array controller counts as one DSSI node. If your
configuration includes HSD05 array controllers, be sure that the
HSD05 is assigned a unique DSSI bus node ID. DSSI node IDs for
the HSD05 are set by switches on the HSD05 controller module
board. The factory default setting is 0.
Refer to the StorageWorks Solutions HSD05 Array Controller
User’s Guide, EK-HSD05-UG, for information on switchpack
settings.

Turn Off
System Power

After setting the bus node IDs, turn off system power.

Installation: VAX-Only Configuration 3–5

Step 2: Connect Ground Cables Between Enclosures

Step 2: Connect Ground Cables Between Enclosures
Daisy Chain
Ground Cables

Attach a number 6 gauge ground cable to the ground terminal
on the system power supply (VAX 4000 Model 100/100A/105A
systems have a ground terminal on the rear of the system box).
Ground cables should be daisy-chained for systems with multiple
enclosures.
Caution

Do not attach more than two ground cables per ground
terminal.

Step 3: Connect DSSI Cables Between Enclosures
DSSI
Connectors
and Cables

Figure 3–2 shows the MR (midrange or micro ribbon) and PS
(pedestal style or pin-socket) DSSI connectors. Appendix A
provides the connector type for each enclosure and DSSI adapter.
Table 3–1 lists the DSSI cable variants used with DSSI
VMSclusters. Refer to the Digital Systems and Options Catalog
for a complete listing of the latest cable order numbers.
Figure 3–2 Midrange and Pedestal Style DSSI Connectors
Midrange or Micro Ribbon
Style Connector

Pedestal or Pin Socket
Style Connector

MLO-007465

3–6 Installation: VAX-Only Configuration

Step 3: Connect DSSI Cables Between Enclosures

Table 3–1 DSSI Cable Variations
Cable

Type

BC21M-09

A micro-ribbon cable with two right-angle 50-pin pin socket connectors.
Used to connect:
VAX 4000 systems to R400X expanders
VAX 4000 systems to VAX 4000 systems
R400X expanders to R400X expanders

BC21Q-xx

A micro-ribbon cable with two straight 50-pin micro-ribbon connectors.

BC22Q-xx

A micro-ribbon cable with one right-angle 50-pin pin-socket connector
and one straight 50-pin micro-ribbon connector. Used to connect:
VAX 3000/4000 systems to TF857/SF100

BC29R-xx

BC29S-xx

A micro-ribbon cable with one right-angle 50-pin micro-ribbon
connector and one straight 50-pin micro-ribbon connector. Used to
connect:
HSD05 array controller to KFMSB adapter
HSD05 array controller to VAX 6000/7000/10000 systems

Installation: VAX-Only Configuration 3–7

Step 3: Connect DSSI Cables Between Enclosures

Check Devices
Using the
Show DSSI
Command

After connecting the DSSI cables, power up the system. Using the
SHOW DSSI command (SHOW UQSSP for KFQSA-based DSSI), check to
see if there are any missing drives. If drives are missing, check
that bus node IDs are unique for each:
•

DSSI host adapter

•

HSD05 array controller

•

HSD30 array controller

•

DSSI storage device—the bus node ID plugs (or DSSI drive
switch settings for devices in a VAX 4000 Model 100/100A
/105A).
Note

If you change the bus node ID plugs, you must recycle
power (press the Reset button or turn on power with the
on/off switch) before the new setting will take effect. The
system reads the bus node ID values at power-up.

Step 4: Set DSSI Device Parameters
DSSI Device
Parameters

In creating a DSSI VMScluster system, you need to set the
following DSSI device parameters according to your configuration:
•

For devices connected through early versions of the HSD05
array controller, this parameter is called DISK_ALCS.

•

UNITNUM — Systems using multiple DSSI buses, as
described in Appendix B, require that the default values
(supplied by bus node ID plugs) be replaced with unique unit
numbers. To set unit numbers and override the default values,
you supply values to the UNITNUM parameter and set a
value of zero to the related device parameter, FORCEUNI.
Typically, devices on the second bus are given unit numbers
starting with 10; devices on the third bus are given unit
numbers starting with 20, and so on.

3–8 Installation: VAX-Only Configuration

Step 4: Set DSSI Device Parameters

Note

Devices connected through the HSD05 and HSD30
array controllers are automatically assigned unique unit
numbers.

•

FORCEUNI — Controls the use of UNITNUM to override
the unit numbers supplied by the bus node ID plug. When
FORCEUNI is set to a value of zero, the operating system
uses the value assigned to the UNITNUM parameter; when
FORCEUNI is set to a value of one, the operating system uses
the value supplied by the bus node ID plug.

•

NODENAME — You can provide your own node names for
drives or you can use the factory-supplied node names.

For More
Parameters

For more information on DSSI parameters and their functions,
refer to Appendix B and VMScluster Systems for OpenVMS.

SET HOST
Command

The firmware console command SET HOST allows you to enter the
Diagnostic and Utility Program (DUP) server utility to modify
the NODENAME, ALLCLASS, UNITNUM, and FORCEUNI
parameters. See Table 3–2 for the command syntax for each
adapter type.

Table 3–2 SET HOST Commands According to Host Adapter Type
System

Adapter Type

Command

HSD05

Array
controller

SET HOST/DUP/DSSI device_name
PARAMS

VAX 4000 Model 300 and
higher,
VAX 4000 Model 100A/105A

Embedded

SET HOST/DUP/DSSI/BUS:[0,1,2,3]
dssi_node_number PARAMS

VAX 3300, 3400,
VAX 4000 Model 100 and 4000
Model 200

Embedded

SET HOST/DUP/DSSI dssi_node_
number PARAMS

All systems

KFQSA

SET HOST/DUP/UQSSP port_
controller_number1 PARAMS

1 The port controller number obtained by using the SHOW UQSSP command

Starting DUP:
Examples

Starting the DUP Server Utility (Embedded DSSI)

>>>SET HOST/DUP/DSSI/BUS:1 0 PARAMS
Starting DUP server...
Copyright (c) 1994 Digital Equipment Corporation
PARAMS>

Installation: VAX-Only Configuration 3–9

Step 4: Set DSSI Device Parameters

Starting the DUP Server Utility (KFQSA-Based DSSI)

>>>SET HOST/DUP/UQSSP/DISK 0 PARAMS
Starting DUP server...
Copyright (c) 1994 Digital Equipment Corporation
PARAMS>

Setting
Allocation
Class

After entering the DUP server utility for a specified device, you
can examine and set the allocation class for the device as follows:
Note

Set the ALLCLASS parameter only through console mode
(PARAMS> prompt). Setting the ALLCLASS parameter
from the operating system is not recommended.
Devices connected through early versions of the HSD05
array controller use the parameter DISK_ALCS for
allocation class; all other DSSI devices use the parameter
ALLCLASS.

1. At the PARAMS> prompt, enter SHOW ALLCLASS to check the

allocation class of the device to which you are currently
connected.
2. Enter SET ALLCLASS 1 (or enter the allocation class you desire).
3. Enter SHOW ALLCLASS to verify the new allocation class.

The following example shows the commands for examining
and changing the allocation class for a specified device. In the
example, the allocation class is changed from class 0 to class 1.
PARAMS>SHOW ALLCLASS
Parameter
Current
Default
Type
Radix
--------- ---------------- ---------------- -------- ----ALLCLASS
0
0
Byte
Dec

PARAMS>SET ALLCLASS 1
PARAMS>SHOW ALLCLASS
Parameter
Current
Default
Type
Radix
--------- ---------------- ---------------- -------- ----ALLCLASS
1
0
Byte
Dec

Setting Unit
Number

After entering the DUP server utility for a specified device, you
can examine and set the unit number for the device as follows:
Note

3–10 Installation: VAX-Only Configuration

Step 4: Set DSSI Device Parameters

1. At the PARAMS> prompt, enter SHOW UNITNUM to check the unit

number of the device to which you are currently connected.
2. Enter SET UNITNUM 10 (or enter the unit number you desire).
3. Enter SET FORCEUNI 0 to override the default unit number value

supplied by the bus node ID plug.
4. Enter SHOW UNITNUM to verify the new unit number.
5. Enter SHOW FORCEUNI to verify that the current value for the

FORCEUNI parameter is 0.
6. Label the device with its unit number, using the unit number

labels shipped with your system.
The following example shows the commands for changing the unit
number of a specified device from number 0 to number 10.
PARAMS>SHOW UNITNUM
Parameter
Current
Default
Type
Radix
--------- ---------------- ---------------- -------- ----UNITNUM
0
0
Word
Dec

PARAMS>SET UNITNUM 10
PARAMS>SET FORCEUNI 0
PARAMS>SHOW UNITNUM
Parameter
Current
Default
Type
Radix
--------- ---------------- ---------------- -------- ----UNITNUM
10
0
Word
Dec

PARAMS>SHOW FORCEUNI
Parameter
Current
Default
Type
Radix
--------- ---------------- ---------------- -------- ----FORCEUNI
0
1 Boolean
0/1

Setting Node
Name

After entering the DUP server utility for a specified device, you
can examine and set the node name for the device as follows:
1. At the PARAMS> prompt, enter SHOW NODENAME to check the

node name of the device to which you are currently connected.
2. Enter SET NODENAME SYSDSK (or enter the desired alphanumeric

node name of up to eight characters).
3. Enter SHOW NODENAME to verify the new node name.

The following example shows the commands for changing the
node name of a specified device from the factory-supplied name to
SYSDSK.

Installation: VAX-Only Configuration 3–11

Step 4: Set DSSI Device Parameters

PARAMS>SHOW NODENAME
Parameter
Current
Default
Type
Radix
--------- ---------------- ---------------- -------- ----NODENAME
R7CZZC
RF35
String Ascii

PARAMS>SET NODENAME SYSDSK
PARAMS>SHOW NODENAME
Parameter
Current
Default
Type
Radix
--------- ---------------- ---------------- -------- ----NODENAME
SYSDSK
RF35
String Ascii

Exiting the
DUP Server
Utility

After you have finished setting and examining DSSI device
parameters for a specified device, enter the WRITE command at
the PARAMS> prompt to save the device parameters you have
changed using the SET command. The changes are recorded to
nonvolatile memory.
Note

•

If you have changed the allocation class or node name of a
device, the DUP server utility will ask you to initialize the
controller. Answer Yes (Y) to allow the changes to be recorded
and to exit the DUP server utility.
PARAMS>WRITE
Changes require controller initialization, ok? [Y/(N)] Y
Stopping DUP server...
>>>

•

If you have not changed the allocation class or node name,
enter the EXIT command at the PARAMS> prompt to exit the
DUP server utility for the specified device.
Note

You must repeat the procedures in this step for each device
for which you want to change parameters.

3–12 Installation: VAX-Only Configuration

Step 5: Configure SCSI Node IDs

Step 5: Configure SCSI Node IDs
When to
Change SCSI
Node Plugs

If two VAX 4000 Model 100/100A/105A systems in a cluster
contain SCSI drives, configure SCSI node IDs so that the
operating system sees each SCSI device name as unique.
To determine if you need to change SCSI node IDs, consider these
points:

Example with
Conflicting
SCSI Device
Names

•

For each system, OpenVMS ‘‘names’’ the first SCSI bus it finds
as bus A; the second SCSI bus as bus B; and so on.

•

All SCSI drives in the DSSI VMScluster are forced to the
allocation class of the host systems.

Table 3–3 shows a sample configuration that calls for changing
SCSI node ID switch settings to avoid duplicate device names.
Note

SCSI unit numbers are forced to 100 x node ID (ID plug).

Table 3–3 Configuration with Conflicting SCSI Device Names
System A
SCSI
Node Console Mode
ID
Device Name

OpenVMS Device Name

DKA0

$1$DKA03

DKA100

$1$DKA1003

DKA200

$1$DKA2003

DKA300

$1$DKA3003

System B

DKA0

$1$DKA03

DKA100

$1$DKA1003

DKA200

$1$DKA2003

DKA300

$1$DKA3003

3 Duplicate SCSI device name

Example with
Unique SCSI
Device Names

To avoid the problem of duplicate SCSI devices names, shown in
Table 3–3, change the SCSI node ID switch settings for the SCSI
drives on System A.

Installation: VAX-Only Configuration 3–13

Step 5: Configure SCSI Node IDs

Figure 3–3 and Table 3–4 show how the devices are uniquely
named after you change the SCSI node ID switches for the SCSI
devices. The SCSI disks off System A are given node ID settings
of 0, 1, 2, and 7 (host adapter 6); and the SCSI disks off System B
are given node ID settings of 3, 4, 5, and 6 (host adapter 7). Note
that in this example, the node ID for the SCSI host adapter in
System A is changed from the default (7) to 6. The command SET
SCSI_ID bus_number node_ID, is used to change the host adapter
node ID.
Figure 3–3 Configuration with Duplicate SCSI Device Names
System A

System B

Vax 4000-100A

Drives (RF)
0,1,2

Drives (RF)
3,4,5

Host Bus Node 6

Host Bus Node 7
DSSI Cable

SZ 12
Expander

Disks (RZ)
0,1

SCSI Cable

SZ 12
Expander

Disks (RZ)
2,7

Disks (RZ)
3,4

SCSI Cable

SZ 12
Expander

Disks (RZ)
5,6
MLO-010975

3–14 Installation: VAX-Only Configuration

Step 5: Configure SCSI Node IDs

Table 3–4 Configuration with Unique SCSI Device Names
System A
SCSI
Node Console Mode
ID
Device Name

OpenVMS Device Name

DKA0

$1$DIA01

DKA100

$1$DKA100

DKA200

$1$DKA200

DKA700

$1$DKA700

Host Adapter

System B

DKA300

$1$DKA300

DKA400

$1$DKA400

DKA500

$1$DKA500

DKA600

$1$DKA600

Host Adapter

1 In this example, the allocation class is 1.

Note

For each SCSI bus that OpenVMS sees as common to both
systems, the total number of drives is limited to eight
(node ID plugs 0–7).

Installation: VAX-Only Configuration 3–15

Step 6: Set Boot Parameters

Step 6: Set Boot Parameters
Boot
Parameters

Set the boot parameters for booting on each system.
Table 3–5 lists the boot environment variables and their related
boot parameters.

Table 3–5 Boot Parameters for VAX Systems
VAX Console Boot Parameters

>>> SET BOOT DUA0

Sets the device or device list from which booting is to be
attempted. In this example, DUA0.

>>> SET BFLAG 0

Sets additional parameters to be passed to the system
software during booting if none are specified. In this
example, system root 0 [SYS0].

>>> SET BFLAG 1

Sets additional parameters to be passed to the system
software during booting if none are specified. In this case
the system will stop at SYSBOOT.

>>> SET BFLAG 10000000

Sets additional parameters to be passed to the system
software during booting if none are specified. In this case
the system boots from the system root [SYS1], not [SYS0].

Boot Parameter
Examples

In the following example boot parameters are set for VAX systems
in a two-system DSSI VMScluster:
# For system A
>>> SET BFLAG 0
>>> SET BOOT DUA0
>>> BOOT
# For system B
>>> SET BFLAG 10000000
>>> SET BOOT DUA0
>>> BOOT

Step 7: Complete the Installation
Complete the software steps of the DSSI VMScluster installation,
such as updating the cluster_config.com file. Refer to the
information provided in Factory Installed Software User
Information or OpenVMS VAX Version 5.5-2 Upgrade and
Installation Manual and VMScluster Systems for OpenVMS.

3–16 Installation: VAX-Only Configuration

4
Troubleshooting
Troubleshooting Procedure
In This Chapter

This chapter provides troubleshooting tips for solving DSSIrelated hardware problems.

Common
Problems

If hardware failures occur, check these common problem sources
first:

Symptoms
and Corrective
Action

•

Loose or missing terminators

•

Incorrect bus node ID plugs (duplicate device names)

•

Duplicate DSSI adapter node IDs

•

Loose or damaged cables or connectors

Table 4–1 lists symptoms and corrective action for AlphaServer
2000/2100 systems.
Table 4–2 lists symptoms and corrective action for DEC 4000 AXP
systems.
Table 4–3 lists symptoms and corrective action for VAX systems.

Troubleshooting 4–1

Troubleshooting Procedure

Table 4–1 Digital AlphaServer 2000/2100 Systems: DSSI Hardware Installation
Troubleshooting
Symptom

Problem

Corrective Action

Fault LED for drive is on
(steady).

Drive failure

Replace drive.

Drives with duplicate bus
node IDs are missing from
the show config display

Duplicate bus
node IDs.

Correct bus node IDs.

Valid drives are missing
from the show config
display.
One drive may appear
seven times on the display.

Drive bus node ID
set to 7 (reserved
for host adapter
ID)

Correct bus node IDs. KFESA bus
node ID for host adapter is set
using the EISA Configuration Utility
(ECU).

Drive activity LEDs do not
come on. Drive missing
from the show config
display.

Missing or loose
cables

Inspect cable connections.

Read/write errors in
console event log; storage
adapter port may fail.

Terminator
missing

Attach terminators as needed.

Problems persist after
eliminating the above
problem sources.

KFESA module
failure

Replace KFESA module.

4–2 Troubleshooting

Troubleshooting Procedure

Table 4–2 DEC 4000 AXP Systems: DSSI Hardware Installation Troubleshooting
Symptom

Problem

Corrective Action

Drives are missing from
the configuration screen
display.

Duplicate bus
node ID plugs (or
a missing plug).

Correct bus node ID plugs.

A drive defaults to zero.
Valid drives are missing
from the configuration
screen display.

"
Bus node ID set to
7, or to that of the
host adapter.
"

One drive appears seven
times on the configuration
screen display.

"
Correct bus node ID plugs.

OpenVMS sees duplicate
drives.

Duplicate unit
numbers (device
names are not
unique).

Provide unique unit numbers using
the cdp command.

Disk power failure LED on
PSC1 is on.

LDC failure.

Replace LDC2 .

LDC OK LED on storage
compartment front panel
is off.

Power-up screen reports
a failing storage adapter
port.

Fault LED for drive is on
(steady).

Drive failure.

Replace drive.

Disk power failure LED on
PSC is on.

Storage drawer
not properly
seated.

Remove drawer and check its
connectors. Reseat drawer.

LDC OK LED on storage
compartment front panel
is off.

Power-up screen reports
a failing storage adapter
port.

Valid drives missing from
the configuration screen
display; read/write errors
in event/error log; storage
adapter port may fail.

Loose or damaged
external DSSI
cable.

Inspect external DSSI cable and
cable connection.

1 PSC refers to the power system controller.
2 LDC refers to the disk power supply.

(continued on next page)

Troubleshooting 4–3

Troubleshooting Procedure

Table 4–2 (Cont.) DEC 4000 AXP Systems: DSSI Hardware Installation Troubleshooting
Symptom

Problem

Corrective Action

Cable: Storage device to
ID panel—Bus node ID
defaults to zero; online
LEDs do not come on.

Missing or loose
internal cables.

Remove storage drawer and inspect
cable connections.

Flex circuit: LDC to
storage interface module—
Disk power failure LED on
PSC is on; LDC OK LED
on storage compartment
front panel is off; and
power-up screen reports
a failing storage adapter
port.

Cable: LDC to storage
interface module—Powerup screen reports a failing
storage adapter port; drive
LEDs do not come on at
power-up.

Cable: LDC to storage
device—Drive does not
show up in configuration
screen display.

Read/write errors in
console event log; storage
adapter port may fail.

Terminator
missing.

Attach terminator to connector port.

DSSI terminator LED
is off or no termination
voltage measured at
connector (pin 38, ground
pin 1); read/write errors;
storage adapter port may
fail.

No termination
power.

Replace LDC (termination power
source for fixed-media storage
compartments).
Replace DC5 converter (termination
power source for storageless fixedmedia storage compartments).

4–4 Troubleshooting

Troubleshooting Procedure

Table 4–3 VAX Systems: DSSI Hardware Installation Troubleshooting
Symptom

Problem

Corrective Action

Drives are missing from
the SHOW DSSI command
display (SHOW UQSSP FOR
KFQSA-BASED DSSI) or
a drive defaults to zero.

Duplicate bus
node ID plugs (or
a missing plug)

Correct bus node ID plugs.

Valid drives are missing
from the configuration
screen display or one drive
appears seven times on
the configuration screen
display.

Bus node ID set to
7, or to that of the
host adapter

Correct bus node ID plugs.

OpenVMS sees duplicate
drives.

Duplicate unit
numbers (device
names are not
unique)

Provide unique unit numbers using
the SET/HOST/DUP/DSSI command.

Valid drives missing from
the configuration screen
display; read/write errors
in event/error log; storage
adapter port may fail.

Loose or damaged
external DSSI
cable

Inspect external DSSI cable and
cable connection.

Cable: storage device to
ID panel—Bus node ID
defaults to zero; device’s
online LEDs do not come
on.

Missing or loose
internal cables

Inspect cable connections.

Read/write errors in
console event log; storage
adapter port may fail

Terminator
missing

Attach terminator to connector port.

DSSI terminator LED
is off or no termination
voltage measured at DSSI
connector (pin 38, ground
pin 1); read/write errors;
storage adapter port may
fail.

No termination
power

Check termination power fuses and
the termination power source—refer
to the service guide for the enclosure.

DSSI Node
Fails to Boot

If a DSSI node fails to boot, perform the following steps:
1. Check the BOOT command you entered.
2. Check the DSSI node ID for the RF device you are trying

to boot from and the unit number specified. Ensure that
the unit number specified in the BOOT command is correctly
programmed into the disk node you wish to boot.
3. Run device tests to check that the boot device is operating.
4. Check that the DSSI bus is terminated.

Troubleshooting 4–5

Troubleshooting Procedure

Termination
Problems

It is especially important to check that only two terminators
are on every bus (at the ends of the bus), even if none of the
above symptoms is present. The SF7x, BA440, BA430, KFMSA,
and KFQSA devices may have internal terminators that are not
visible externally. These devices do not have the green lights
found on the external terminators.

Grounding and
Bus Lengths

Excessive ground offset voltages or DSSI bus length over the
maximum can cause virtual circuit closures, system crashes, or
degradation in performance. All enclosures should be grounded
using number 6 gauge wire, and DSSI bus lengths must be within
the limits specified in Chapter 1.

DSSI-Related
Commands

Table 4–4 provides a summary of DSSI-related console
commands.

Table 4–4 DSSI Related Console Commands
Adapter Type

Command

Function

VAX Console Commands

Embedded
(multiple
buses)

SET HOST/DUP
/DSSI/BUS:[0,1,2,3] dssi_node_
number PARAMS

Allows you to enter the DUP server
to modify DSSI parameters.

Embedded
(single bus)

SET HOST/DUP/DSSI dssi_node_
number PARAMS

Allows you to enter the DUP server
to modify DSSI parameters.

HSD05
/HSD30
array
controller

SET HOST/DUP/DSSI device_
name PARAMS

Allows you to enter the DUP server
for an HSD05 or HSD30 array
controller to modify parameters.

Embedded
(late models
only)1

SET DSSI_ID bus_number bus_
node

Use this command to override the
default bus node numbers for a
specified host adapter. Assigning a
value of F for bus_node returns the
default determined by the bus node
ID plug. These values are stored in
nonvolatile FEPROM.

Embedded
(late models
only)1

SHOW DSSI_ID

Displays the current bus node
settings for the onboard (SHAC)
host adapters.

Embedded

SHOW DSSI

Displays DSSI devices and
parameters

KFQSA

SET HOST/DUP/UQSSP port_
controller_number 2 PARAMS

Allows you to enter the DUP server
to modify DSSI parameters.

1 Late models include VAX 4000 Model 100A, 500A, 600A, and 700A.
2 The port controller number obtained by using the SHOW UQSSP command

(continued on next page)

4–6 Troubleshooting

Troubleshooting Procedure

Table 4–4 (Cont.) DSSI Related Console Commands
Adapter Type

Command

Function

VAX Console Commands

KFQSA

SHOW UQSSP

Displays DSSI devices and
parameters for devices connected to
the KFQSA storage adapter.

Embedded
(VAX 4000
Model 100
/100A/105A)

SET SCSI_ID bus_number node_
ID

Use this command to override the
default node ID for the specified
SCSI host adapter. These values
are stored in nonvolatile FEPROM.

AXP Console Commands

HSD05 array
controller

set host -dup -dssi device_name

Allows you to enter the DUP server
for an HSD05 array controller to
modify parameters.

Embedded
/KFESA

cdp

Allows you to modify and examine
NODENAME, ALLCLASS, and
UNITNUM parameters. The cdp
command automatically connects
to the device’s DUP server for
all devices in the cluster or any
number of specified devices.

N710 (DEC
4000 AXP)

set NCRn_SETUP

Allows you to change the bus mode
and bus node numbers for DEC
4000 embedded host adapters.

Embedded
/KFESA

show config

Displays the buses on the system
and the devices found on those
buses.

For More
Information

For additional troubleshooting information, refer to the system
service information.

Troubleshooting 4–7

A
Electrical Lengths By Enclosure
DSSI Bus Lengths by Enclosure
Lengths of
Interconnects

Table A–1 gives the maximum electrical lengths for embedded
DSSI interconnects within the various enclosures, as well as the
number and type of DSSI connector.

Table A–1 Electrical Lengths of Embedded DSSI Interconnects in Enclosures
Enclosure/Device

Connector Type

Internal DSSI Length

KFESA/B adapter using one
connector (end-node)

1 external MR1

0.15 m (6 in)

KFESA/B adapter using two
connectors (middle-node)

2 external MR1

0.6 m (24 in)

KFMSB

4 external MR

2.4 m (95 in)

R400x through-bus mode; no internal
terminator; both upper and lower
rows

2 external PS2

2.36 (93 in)

R400x split bus mode 1; no internal
terminator; upper row only

2 external PS

1.68 m (66 in)

R400x split bus mode 2; no internal
terminator; lower row only

2 external PS

1.02 m (40 in)

BA640 embedded storage (Bus A–D)
has internal terminator; DEC 4000
Model 6xx

4 external PS (one
for each of four
buses, A–D)

1.8 m (71 in)

BA641 embedded storage (Bus A–D)
has internal terminator; rackmount
DEC 4000 Model 6xx

4 external PS (one
for each of four
buses, A–D)

0.38 m (15 in)

BA440 embedded storage (BUS 0) has
internal terminator; VAX 4000-300
and higher

1 external PS

1.32 m (52 in)

1 MR is a midrange or micro ribbon style shielded connector used for bulkhead mounting. This connector mates with MR

only.
2 PS is a pin-and-socket style shielded connector used for bulkhead mounting. This connector mates with PS only.

(continued on next page)

Electrical Lengths By Enclosure A–1

DSSI Bus Lengths by Enclosure

Table A–1 (Cont.) Electrical Lengths of Embedded DSSI Interconnects in Enclosures
Enclosure/Device

Connector Type

Internal DSSI Length

BA440 in/out port (BUS 1), no
internal terminator; VAX 4000-300
and higher

2 external PS

0.51 m (20 in)

BA440 in/out port (BUS 2), no
internal terminator; VAX 4000-300
and higher

2 external PS

1.4 m (56 in)

BA440 in/out port (BUS 3), no
internal terminator; VAX 4000-300
and higher

2 external PS

1.4 m (56 in)

BA441 embedded storage (BUS 0) has
internal terminator; VAX 4000-300
and higher

1 external PS

2.45 m (96 in)

BA441 in/out port (BUS 1), no
internal terminator; VAX 4000-300
and higher

2 external PS

0.51 m (20 in)

BA441 in/out port (BUS 2), no
internal terminator; VAX 4000-300
and higher

2 external PS

1.4 m (56 in)

BA441 in/out port (BUS 3), no
internal terminator; VAX 4000-300
and higher

2 external PS

1.4 m (56 in)

BA430 embedded storage (BUS 0) has
internal terminator; VAX 4000-200

1 external PS

1.37 m (54 in)

BA431 embedded storage (BUS 0) has
internal terminator; VAX 4000-200

1 external PS

2.45 m (96 in)

BA42 embedded storage (BUS 0) has
internal terminator; VAX 4000-100
/100A/105A

1 external PS

0.76 m (30 in)

BA42 embedded storage (BUS 1), no
internal terminator; VAX 4000-100
/100A/105A

2 external PS

1.08 m (43 in)

BA213; has internal terminator

1 external PS

1.14 m (45 in)

B213F; has internal terminator

1 external PS

0.51 m (20 in)

BA215; has internal terminator

1 external PS

0.76 m (30 in)

R215F; no internal terminator

1 external PS

1.52 m (60 in)

R23RF; no internal terminator

2 external PS

1.0 m (39 in)

KFQSA adapter with 1 connector
directly attached to KFQSA (for
example, BA440)

1 external PS

N/A

(continued on next page)

A–2 Electrical Lengths By Enclosure

DSSI Bus Lengths by Enclosure

Table A–1 (Cont.) Electrical Lengths of Embedded DSSI Interconnects in Enclosures
Enclosure/Device

Connector Type

Internal DSSI Length

KFQSA adapter with 2 connectors
directly attached to KFQSA (for
example, BA440)

2 external PS

0.31 m (12 in)

SF12 in through-bus mode; 1 to 4
drives per bus; no internal terminator

2 external MR2

1.25 m (50 in)

SF35 in through-bus mode; 1 to 6
drives per bus; no internal terminator

2 external MR2

2.13 m (84 in)

SF35 in split-bus mode; 1 to 3
drives per bus using internal
terminator

1 external MR

1.07 m (42 in)

SF7x in through-bus mode; 1 to 4
drives per bus; no internal terminator

2 external MR

4.27 m (168 in)

SF72x in split bus mode; 1 or 2
drives using internal SF72 terminator

1 external MR

2.12 m (84 in)

TF857; no internal terminator

2 external MR

0.25 m (10 in)

2 PS is a pin-and-socket style shielded connector used for bulkhead mounting. This connector mates with PS only.

Electrical Lengths By Enclosure A–3

B
Storage Device Parameters
Examining Storage Device Parameters on AXP Systems
show device
Command

>>> show device

dka600.6.0.1.0
dua0.0.0.2.1
dua1.1.0.2.1
dua2.2.0.2.1
dua3.3.0.2.1
dua4.4.0.2.1
dua5.5.0.2.1
dva0.0.0.0.1
mka500.5.0.1.0
ewa0.0.0.0.0
pka0.7.0.1.0
pua0.7.0.2.1
pub0.6.0.3.1
>>>

The show device command displays information for all DSSI and
SCSI devices in the system. The following example provides a
sample display:

DKA600
RRD43 2893
$2$DIA0 (ALPHA0)
RF35
$2$DIA1 (ALPHA1)
RF35
$2$DIA2 (ALPHA2)
RF35
$2$DIA3 (ALPHA3)
RF35
$2$DIA4 (ALPHA4)
RF35
$2$DIA5 (ALPHA5)
RF35
DVA0
RX26
MKA500
TLZ06 0435
EWA0
08-00-2B-3B-42-FD
PKA0
SCSI Bus ID 7
PAA0
DSSI Bus ID 7
PAB0
DSSI Bus ID 6
The numbered elements in the display are explained in the
following annotations.

Storage Device Parameters B–1

Examining Storage Device Parameters on AXP Systems

! Console device name:

dka0.0.0.0.0

Hose Number: 0 PCI_0 (32-bit PCI); 1 EISA; 2 PCI_1
Slot Number:

For EISA options---Correspond to EISA card cage slot numbers (1--*)
For PCI options---Slot 0 = Ethernet adapter (EWA0) or
reserved on AlphaServer 2000 systems.
Slot 1 = SCSI controller on standard I/O or I/O backplane
Slot 2 = EISA to PCI bridge chip
Slots 3--5 = Reserved
Slots 6--8 = Correspond to PCI card cage slots: PCI0, PCI1, and PCI2

Channel Number: Used for multi-channel devices.
Bus Node Number: Bus Node ID
Device Unit Number: Unique device unit number
SCSI unit numbers are forced to 100 x Node ID
Storage Adapter ID: One-letter adapter designator (A,B,C...)
Driver ID:

Two-letter port or class driver designator:
DR--RAID-set device
DV--Floppy drive
ER--Ethernet port (EISA)
EW--Ethernet port (PCI)
PK--SCSI port, DK--SCSI disk, MK--SCSI tape
PU--DSSI port, DU--DSSI disk, MU--DSSI tape

" Operating system device name:

MA043993

•

For an allocation class of zero: NODENAME$DIAu
NODENAME is a unique node name and u is the unit
number. For example, R7BUCC$DIA0.

•

For a nonzero allocation class:
$ALLCLASS$DIAu
ALLCLASS is the allocation class for the system and
devices, and u is a unique unit number. For example,
$1$DIA0.

# Node name (alphanumeric, up to 6 characters)
$ Device type
% Firmware version (if known)

Examining DSSI Device Parameters on VAX Systems
SHOW DSSI
Command

Enter SHOW DSSI to display DSSI devices on embedded DSSI
adapters. For each storage device on an embedded DSSI, the
firmware displays two lines:
•

The first line contains the bus number, node number, and node
name.

B–2 Storage Device Parameters

Examining DSSI Device Parameters on VAX Systems

•

The second line contains the device name and unit number
followed by the device type in parentheses.

The device name consists of letters, such as DIA or DIB (MIA or
MIB for the TF-series tape drive) and a unique unit number:
devices on bus 0 are listed as DIA
devices on bus 1 are listed as DIB
devices on bus 2 are listed as DIC
devices on bus 3 are listed as DID
The embedded DSSI adapter for each bus is identified by an
asterisk (*).
Note

Under operating system control, all drives are seen as DIA
and MIA.

SHOW DSSI
Example

The following embedded DSSI display shows a system with four
DSSI devices (unit numbers 0–2, and 5) and an R400X expander
with seven DSSI devices (unit numbers 0–6).
>>>SHOW DSSI
DSSI Bus 0 Node 0 (R7ALUC)
-DIA0 (RF73)
DSSI Bus 0 Node 1 (R7EB3C)
-DIA1 (RF73)
DSSI Bus 0 Node 2 (R7EB22)
-DIA2 (RF73)
DSSI Bus 0 Node 5 (TFDR1)
-MIA5 (TF85/TF86)
DSSI Bus 0 Node 6 (*)
DSSI Bus 1 Node 0 (SNEEZY)
-DIB0 (RF73)
DSSI Bus 1 Node 1 (DOPEY)
-DIB1 (RF73)
DSSI Bus 1 Node 2 (SLEEPY)
-DIB2 (RF73)
DSSI Bus 1 Node 3 (GRUMPY)
-DIB3 (RF73)
DSSI Bus 1 Node 4 (BASHFUL)
-DIB4 (RF73)
DSSI Bus 1 Node 5 (HAPPY)
-DIB5 (RF73)
DSSI Bus 1 Node 6 (DOC)
-DIB6 (RF73)
DSSI Bus 1 Node 7 (*)
>>>

Storage Device Parameters B–3

Examining DSSI Device Parameters on VAX Systems

SHOW UQSSP
Command

Enter SHOW UQSSP to display DSSI devices on KFQSA-based
adapters. For each storage device on KFQSA-based DSSI, the
firmware displays two lines:
•

The first line contains the UQSSP disk controller number and
device node name.

•

The second line contains the device name and unit number
followed by the device type in parentheses.
For KFQSA-based DSSI, the device name consists of the
letters DUcu, where c is the controller letter, and u is a unique
unit number.
Note

Under operating system control, all drives are seen as DIA
and MIA.

SHOW UQSSP
Example

The following display shows a sample KFQSA-based DSSI bus.
>>>SHOW UQSSP
UQSSP Disk Controller 0 (772150)
-DUA0 (RF73)
UQSSP Disk Controller 1 (760334)
-DUB1 (RF73)
UQSSP Disk Controller 2 (760340)
-DUC2 (RF73)
UQSSP Disk Controller 3 (760322)
-DUD3 (RF73)
UQSSP Tape Controller 0 (774500)
-MUA0 (TK70)
>>>

B–4 Storage Device Parameters

DSSI Device Parameters

DSSI Device Parameters
Principal
Parameters

Parameter
Descriptions

Five principal parameters are associated with each DSSI device:
•

Bus node ID

•

ALLCLASS

•

UNITNUM (and FORCEUNI)

•

NODENAME

•

SYSTEMID

Bus Node ID

The bus node ID parameter for DSSI storage devices is provided
by the bus node ID plug on the front panel of the storage
compartment (VAX 4000 Model 100/100A/105A systems use the
device bus node switches). Each DSSI bus can support up to eight
nodes, bus nodes 0–7. Each DSSI adapter, HSD05/HSD30 array
controller, and each DSSI storage device counts as a node. Hence:
1. In a single-system configuration, a DSSI bus can support up

to seven devices, bus nodes 0–6 (with node 7 reserved for the
adapter).
2. In a two-system DSSI VMScluster configuration, the bus can

support up to six devices, 0–5 (with nodes 6 and 7 reserved for
the adapters).
3. In a three-system DSSI VMScluster configuration, the bus can

support up to five devices, 0–4 (with nodes 5, 6, and 7 reserved
for the adapters).
4. In a four-system DSSI VMScluster configuration, the bus can

support up to four devices, 0–3 (with nodes 4, 5, 6, and 7
reserved for the adapters).

Storage Device Parameters B–5

DSSI Device Parameters

Note

Drives connected through the HSD05/HSD30 array
controllers do not count as DSSI nodes; thus, using
multiple HSD controllers, up to 42 SCSI drives can be
configured in a two-system DSSI VMScluster, provided you
have sufficient storage expansion hardware.

•

The bus node ID for KFESA/B host adapters is set using the
EISA Configuration Utility (ECU).

•

The bus node ID for the HSD05 array controller is set by
switches on the HSD05 controller module board.

•

The bus node ID for the HSD30 array controller is set through
the HSD30 maintenance terminal.

•

DEC 4000 host adapter IDs are set through the NCRnn_
SETUP environment variable.

•

Late model VAX system host adapter IDs can be set using the
SET DSSI_ID command.

ALLCLASS
Note

For devices connected through the early versions of
the HSD05 array controller, this parameter is called
DISK_ALCS.

The ALLCLASS parameter determines the device allocation
class. The allocation class is a numeric value from 0–255 that
is used by the OpenVMS AXP operating system to derive a
path-independent name for multiple access paths to the same
device. The ALLCLASS firmware parameter corresponds to the
OpenVMS AXP IOGEN parameter ALLOCLASS.
DSSI devices are shipped from the factory with a default
allocation class of zero.
Note

Each device to be served to a cluster must have a nonzero
allocation class that matches the allocation class of the
system.

Refer to VMScluster Systems for OpenVMS for rules on specifying
allocation class values.

B–6 Storage Device Parameters

DSSI Device Parameters

UNITNUM

The UNITNUM parameter determines the unit number of the
device. By default, the device unit number is supplied by the bus
node ID plug on the front panel of the storage compartment.
Note

Systems using multiple DSSI buses require that the
default values be replaced with unique unit numbers. See
the section ‘‘How OpenVMS AXP Uses the DSSI Device
Parameters .’’

To set unit numbers and override the default values, use the cdp
console command to supply values to the UNITNUM parameter.
Note

Devices connected through the HSD05/HSD30 array
controllers are automatically assigned unique unit
numbers.

NODENAME

The NODENAME parameter allows each device to have an
alphanumeric node name of up to six characters. DSSI devices
are shipped from the factory with a unique identifier, such as
R7CZZC, R7ALUC, and so on. You can provide your own node
name, keep the factory-supplied node names, or use the cdp
console command to supply node names that relate to the device
name conventions for AXP systems.
SYSTEMID

The SYSTEMID parameter provides a number that uniquely
identifies the device to the operating system. This parameter
is modified when you replace a device using warm-swapping
procedures. The SYSTEMID parameter is changed using the
DUP server for the specified device.

How OpenVMS AXP Uses the DSSI Device Parameters
Allocation
Class Zero

With an allocation class of zero, the operating system can use the
default parameter values to provide each device with a unique
device name. The operating system uses the node name along
with the device logical name as follows:
NODENAME$DIAu

Storage Device Parameters B–7

How OpenVMS AXP Uses the DSSI Device Parameters

NODENAME is a unique node name and u is the unit number.
For example, R7BUCC$DIA0.

Nonzero
Allocation
Class

With a nonzero allocation class, the operating system relies
on unit number values to create a unique device name. The
operating system uses the allocation class along with the device
logical name as follows:
$ALLCLASS$DIAu
ALLCLASS is the allocation class for the system and devices, and
u is a unique unit number. For example, $1$DIA0.

Multiple and
Shared Buses

Using multiple host adapters, you can fill up to six DSSI buses
for VAX systems (for AXP systems the number of KFESB host
adapters is only limited by the number of available EISA slots).
Each bus can have up to seven DSSI drives (bus nodes 0–
6). When a bus is shared between two systems in a DSSI
VMScluster, six DSSI drives can be shared; in a three-system
DSSI VMScluster, five DSSI drives can be shared; in a
four-system DSSU VMScluster four DSSI drives can be shared.
When more than one bus is being used, and your system is
using a nonzero allocation class, you need to assign new unit
numbers for devices on all but one of the DSSI buses, since the
unit numbers for all DSSI storage devices connected to a system’s
associated DSSI buses must be unique.
Note

Drives connected through the HSD05/HSD30 array
controllers do not count as DSSI nodes; thus, using
multiple HDS05/HSD30 controllers, up to 36 SCSI drives
can be configured in a two-system DSSI VMScluster.
Devices connected through the HSD05/HSD30 array
controllers are automatically assigned unique unit
numbers.

Example of
Duplicate
Device Names

Figure B–1 illustrates the problem of duplicate operating system
device names for a system that is using more than one DSSI
bus and a nonzero allocation class. In the case of the nonzero
allocation class, the operating system sees four of the devices
as having duplicate device names. This is an error, as all unit
numbers must be unique. The unit numbers for one of the two
DSSI buses in this example need to be reprogrammed.

B–8 Storage Device Parameters

How OpenVMS AXP Uses the DSSI Device Parameters

Figure B–1 How OpenVMS Sees Unit Numbers for DSSI Devices

Allocation Class=0

Nonzero Allocation Class
(Example: ALLCLASS=1)

R7BUCC$DIA0

$1$DIA0

R7CZZC$DIA1

$1$DIA1

R7ALUC$DIA2

$1$DIA2

R7EB3C$DIA3

$1$DIA3

R7IDFC$DIA0

$1$DIA0

R7IBZC$DIA1

$1$DIA1

R7IKJC$DIA2

$1$DIA2

R7ID3C$DIA3

$1$DIA3

R7XA4C$DIA4

$1$DIA4

R7QIYC$DIA5

$1$DIA5

R7DA4C$DIA6

$1$DIA6

* Duplicate 0
* Duplicate 1
* Duplicate 2
* Duplicate 3

* Nonzero allocation class examples with an asterisk indicate duplicate device names.

For one of the DSSI buses, the unit numbers need to be reprogrammed to avoid this error.
LJ-02063-TI0

Storage Device Parameters B–9

C
Sample DSSI VMScluster Configurations for
VAX Systems
Configuration Considerations
In setting up your DSSI VMScluster for VAX systems, you need
to consider your cluster’s requirements for performance, storage
capacity, and data availablility. You also need to consider whether
the systems you plan to cluster are compatible in performance.
If you have older systems, you may need to consider upgrading
them to ensure balance in adapter performance.

Combinations
of Systems

It is important to consider the performance levels of the systems
you plan to cluster. Ideally, you should cluster systems of similar
performance levels to ensure that the loss of a system from the
cluster will not adversely affect the overall capacity of the cluster.
For example, a VAX 4000 Model 300 should not be clustered
with two MicroVAX II systems, because the VAX 4000 Model 300
is more than eight times more powerful than a MicroVAX II.
Removal of the VAX 4000 Model 300 in such a cluster represents
an 80 percent loss of capacity.

Adapters
and System
Performance

Digital strongly recommends that older MicroVAX II and
MicroVAX 3xxx systems in three-system DSSI VMScluster
systems be upgraded to at least a VAX 4000 Model 200. This
ensures that the cluster operates optimally by minimizing the
disparity between adapter and system performance. Use of the
same DSSI adapter (SHAC) on two machines also guarantees that
adapter performance is balanced. See Table 1–3 for differences in
adapter performance.

Configuring
for High
Performance

When configuring for highest VMScluster performance, you
need to maximize I/O capacity. To do so, ensure that all cluster
storage is directly accessible to all systems residing on the DSSI
interconnects (see Figure C–1). With direct storage access, fewer
devices intervene between a user’s terminal and the disk on which
required information is stored, and I/O requests are serviced
speedily. Direct connection also eliminates server overhead.

Sample DSSI VMScluster Configurations for VAX Systems C–1

Configuration Considerations

Figure C–1 Directly Shared Disks for High Performance

VAX
4000-300
or Higher

DSSI Bus 0

DISK

DSSI Bus 1

DISK

DSSI Bus 2

DISK

DISK
MLO-007463

Configuring
for Storage
Capacity

When configuring for maximum storage capacity, you can use
the Mass Storage Control Protocol (MSCP) to serve storage to
cluster members. To ensure highest MSCP service performance,
configure the most powerful systems with the highest-performing
adapters as MSCP servers and ensure that those systems are not
overloaded with other processing tasks. Also, it is preferable to
locate heavily used files on devices with direct storage and locate
less active files on served devices.
Although the cluster shown in Figure C–2 provides excellent
storage capacity, it runs the risk of lost access to storage as a
result of a single-path access to most disks.

Configuring
for Data
Availability

Access to storage upon failure of a system is a key factor in
creating and maintaining maximum data availability to users,
especially in configurations without direct storage. To ensure
access to data, you can attach two MSCP servers (and therefore
two systems) to the disk, enabling failover to occur if one system
fails.

C–2 Sample DSSI VMScluster Configurations for VAX Systems

Configuration Considerations

Figure C–2 Configuring for Capacity

DISK

DISK
One DSSI Shared
Among All Systems

VAX
4000-200
System

VAX
4000-300
or Higher

DISK

DSSI Not Shared

DISK

DSSI Not Shared

DISK

VAX
4000-200
System

DISK

DSSI Not Shared

DISK

DSSI Not Shared

DISK

DSSI Not Shared

DISK

DISK
MLO-007453

Another way to ensure data availability is to put disks in
enclosures separate from the systems. If it becomes necessary to
shut down power in an enclosure, the loss will not affect both the
system and the disk. It is also recommended that enclosures be
connected to different power sources to avoid loss of access if an
outlet fails.
It is wise to have at least two boot nodes, so that if one becomes
unavailable, satellites can boot from the other.

Sample DSSI VMScluster Configurations for VAX Systems C–3

Configuration Considerations

Using Multiple DSSI Interconnects for Redundancy

The DSSI Interconnect is DC coupled and uses low-level signals.
DC coupling ensures that devices, connectors, cables, adapters,
and so on are not isolated electrically. In contrast, CI VMScluster
systems are AC coupled and are isolated electrically. AC coupling
allows you to disconnect cables while systems are running without
causing electrical or data-integrity problems. DC coupling does
not. DSSI does not allow you to disconnect a cable, short circuit a
connector, or in any other way affect the electrical characteristics
of a pathway while the cluster is running. Therefore, anything
that happens on an interconnect or pathway affects all devices
connected to that interconnect.
By distributing disks over multiple buses, you isolate the effects
of a bus failure and avoid building in a single point of failure.
Furthermore, use of multiple interconnects provides additional
paths for host-to-host communication if one interconnect fails.
With multiple buses, you can also split the I/O load by placing
disks on each bus. By adding volume shadowing, you can
duplicate the data on multiple disks connected by different buses.
Thus, loss of a bus would not affect cluster operation, since the
shadow members on the remaining bus could continue to operate
and provide service.
Figure C–3 shows 12 disks, each of which is accessible via at least
two DSSI interconnects.
Using Volume Shadowing to Prevent Loss of Access or Data

Common system disks are normally used to minimize the system
management of three-system DSSI VMScluster systems. For that
reason, it is wise to use Digital’s Volume Shadowing software to
maintain multiple copies of the system disk for use if hardware
fails. With volume shadowing, if a failure occurs (for example, the
system disk or its power source or bus breaks down) the system
can use another member of the shadow set.
The same principle applies to user or data disks. If all data is
kept on one disk or on disks on a single interconnect, upon failure
the users will not have access to their data. Worse, if the disk
becomes corrupted, they may lose their data. You can prevent loss
of access by shadowing critical data disks. Shadowing should also
be used from one bus to another. It is wise to keep critical disks
in different storage enclosures to prevent loss of data if a power
failure occurs in the enclosure.

C–4 Sample DSSI VMScluster Configurations for VAX Systems

Configuration Considerations

Figure C–3 Using Multiple DSSI Interconnects for Redundancy
Satellite

Satellite

Ethernet
MSCP Server

MSCP Server

MSCP Server
VAX
4000-300
or Higher

Any Q-bus
System

DSSI Interconnect

DISK

DSSI Interconnect

System
Disk

DSSI Interconnect

DISK

DISK
MLO-007452

Sample DSSI VMScluster Configurations for VAX Systems C–5

Sample Configurations

Sample Configurations
This section contains conceptual and cabling illustrations of
sample configurations that you can use as reference material
in planning and cabling your own configuration. Each figure
contains a diagram of a configuration, followed by one or more
diagrams that show how that configuration is cabled with
different storage expansion enclosures. A shaded (and numbered)
disk or tape in the cabling illustrations indicates that the device
is attached to a DSSI bus.
The following configurations are shown:
•

Figure C–4, Two-System DSSI VMScluster with Maximum
Shared Storage

•

Figure C–5, Three-System DSSI VMScluster Using Three
DSSI Interconnects

•

Figure C–6, Three-System DSSI VMScluster Using Four DSSI
Interconnects

C–6 Sample DSSI VMScluster Configurations for VAX Systems

Sample Configurations

Figure C–4 Two-System DSSI VMScluster with Maximum Shared Storage
Ethernet

CPU (Any Q-Bus VAX)

VAX
4000-500A
or Higher

DSSI Bus Interconnect

DISK

System
Disk

DISK

DSSI Bus Interconnect

DISK

DSSI Bus Interconnect

DISK

DSSI Bus Interconnect

DISK

DISK
MLO-008546

(continued on next page)

Sample DSSI VMScluster Configurations for VAX Systems C–7

Sample Configurations

Figure C–4 (Cont.) Two-System DSSI VMScluster with Maximum Shared Storage
VAX 4000-500A
or Higher

R400X Expander

3 2 1 0

5 4

VAX 4000-500A
or Higher

Ethernet

R400X Expander

3 2 1 0

5 4

MLO-008559

C–8 Sample DSSI VMScluster Configurations for VAX Systems

Sample Configurations

Figure C–5 Three-System DSSI VMScluster Using Three DSSI Interconnects
Ethernet

Any
Q-bus VAX
4000-200

VAX
4000-300
or Higher

Any
Q-bus VAX
4000-200

DSSI Bus Interconnect

Disk

System
Disk

Disk

Disk
DSSI Bus Interconnect

MSCP Served
Storage
Disk

Disk

Disk
DSSI Bus Interconnect

Disk

MLO-008551

(continued on next page)

Sample DSSI VMScluster Configurations for VAX Systems C–9

Sample Configurations

Figure C–5 (Cont.) Three-System DSSI VMScluster Using Three DSSI Interconnects
Shared Storage
VAX 4000-200

R400X Expander

3 2 1

VAX 4000-500A
or Higher

VAX 4000-200

Ethernet

MSCP Served Storage
R400X Expander

3 2 1
5 4

R400X Expander

3 2 1

5 4

MLO-008540

C–10 Sample DSSI VMScluster Configurations for VAX Systems

Sample Configurations

Figure C–6 Three-System DSSI VMScluster Using Four DSSI Interconnects
Ethernet
VAX
4000-300
or Higher

VAX
4000-300
or Higher

DSSI Bus Interconnect

Disk

System
Disk

Disk

DSSI Bus Interconnect

Disk

DSSI Bus Interconnect

Disk

DSSI Bus Interconnect

Disk

Disk
MLO-009761

(continued on next page)

Sample DSSI VMScluster Configurations for VAX Systems C–11

Sample Configurations

Figure C–6 (Cont.) Three-System DSSI VMScluster Using Four DSSI Interconnects
VAX 4000-500A
or Higher

VAX 4000-500A
or Higher

Ethernet

R400X Expander

3 2 1 0
4

R400X Expander

3 2 1

R400X Expander

3 2 1

R400X Expander

3 2 1 0
4

MLO-009760

C–12 Sample DSSI VMScluster Configurations for VAX Systems

Index
A
Adapters
and performance, C–1
SET HOST commands for, 3–9, 4–6
ALLCLASS parameter, B–6
Allocation class, setting, 3–10
Allocation class, using set host, 2–18
Availability, data, configuring for, C–2
Availability, UPS for, 1–7

B
Boot parameters
examples, 2–25
setting, 2–24, 3–16
Boot restrictions, 1–4
Bus mode
changing for DEC 4000 AXP host adapters,
2–7
Bus node ID plugs
configuring, 2–11, 3–3
Bus node IDs
changing for DEC 4000 AXP host adapters,
2–5
changing for HSD30 array controllers,
2–5, 3–4
changing for KFESA host adapters, 2–5
changing for KFMSB host adapters, 2–5
Bus node numbers
changing for DEC 4000 AXP host adapters,
2–7
changing for HSD30 array controllers,
2–9, 3–4
changing for KFMSB adapters, 2–10
changing for VAX host adapters, 3–4

C
Cables
See DSSI cables; Ground cables
cdp command, 2–15
Configurations
AXP only, 1–1
considerations for, C–1
diskless DSSI buses, 2–7, 3–4
dual-architecture, 1–1

Configurations (cont’d)
examining, 2–14
examining DSSI configuration, 3–8
maximum number of enclosures, 1–7
power bus, 1–7
sample, 3–1, C–1, C–6
sample AXP only, 2–1, 2–2
sample dual-architecture, 2–3
VAX only, 1–1
Console commands
cdp, 2–15
set bflag, 2–24
SET BFLAG, 3–16
set boot, 2–24
SET BOOT, 3–16
set bootdef_dev, 2–24
set boot_osflags, 2–24
SET DSSI_ID, 3–3
SET HOST, 3–9
set host -dup -dssi, 2–17
show device, B–1
SHOW DSSI, B–2
SHOW DSSI_ID, 3–3
SHOW UQSSP, B–4
Console device name, B–2

D
Data, protecting, C–4
DECnet license, 1–5
Device parameters
See Storage parameters
See Storage parameters; DSSI device
parameters
Devices, missing, 2–14, 3–8
DISK_ALCS parameter, B–6
DSSI adapter characteristics, 1–8
DSSI bus
electrical lengths by enclosure, A–1
maximum lengths, 1–5
termination, 1–7
DSSI cables
connecting, 2–12, 3–6
order numbers, 2–13
variations, 2–13, 3–7

Index–1

DSSI connectors, 2–12
midrange, 3–6
DSSI device name
example of duplicate names, B–8
DSSI device parameters
defined, B–5
function of, B–5
list of, B–5
modifying, 2–15, 3–8
reprogramming, B–8
use by OpenVMS AXP, B–7
DSSI nodes, 1–2
DSSI parameters, 3–8, B–2
ALLCLASS, 2–14
NODENAME, 2–14
UNITNUM, 2–14
DSSI VMScluster configurations, high
performance, C–1
DSSI VMScluster guidelines, 1–7
DUP server utility
exiting, 2–20, 3–12

E
Enclosures
bus lengths, A–1
maximum number, 1–7
Environment variables
bflag, 2–24
boot, 2–24
bootdef_dev, 2–24
boot_osflags, 2–24
NCRn_SETUP, 2–7

F
FDDI support, 1–3

G
Ground cables, 1–7
connecting, 2–12, 3–6
Ground offset
limits, 1–6
measuring, 1–6
Grounding requirements, 1–6

H
Host adapters, 2–8, 3–3
HSD05 array controller, 2–15
HSD05 bus node ID
configuring, 2–11, 3–5
HSD30
set other_controller, 2–9, 3–4
set this_controller, 2–9, 3–4

Index–2

I
Installation procedure, 2–7, 3–3

K
KFMSB
modify command, 2–10

L
Licenses
DECnet, 1–5
VAXcluster software, 1–5
Licensing requirements, 1–5

M
MSCP, C–2

N
NCRn_SETUP, 2–7
example, 2–8
Node name, setting, 3–11
Node name, setting with set host, 2–19
NODENAME parameter, B–7

P
Performance
adapters and, C–1
configuring for, C–1
maximizing, C–1

R
Redundancy, using multiple DSSI
interconnects for, C–4

S
SCSI device names
conflicting, example of, 2–22, 3–13
unique, example of, 2–21, 3–13
SCSI drives
DSSI VMScluster limitations, 1–3, 1–4,
2–23, 3–15
limits in a DSSI VMScluster, 1–4
SCSI node ID
configuring, 3–13
SCSI node ID plugs
configuring, 2–21, 3–13
set bflag command, 2–24
SET BFLAG command, 3–16
set boot command, 2–24

SET BOOT command, 3–16
set bootdef_dev command, 2–24
set boot_osflags command, 2–24
SET DSSI_ID command, 3–3
set host -dup command, 2–17
SET HOST command, 3–9
Setting DSSI parameters
See cdp
show device command, B–1
SHOW DSSI command, B–2
SHOW DSSI_ID command, 3–3
SHOW UQSSP command, B–4
Site verification, 1–6
Software installation, 2–25, 3–16
Software requirements, 1–5
Storage bus locations, 2–8
Storage capacity, configuring for, C–2
Storage capacity, enclosure
and cable connectors, 3–6
Storage parameters
described, B–5
examining, B–1, B–2, B–4
examining with set host, 2–17
use by OpenVMS, B–7

System combinations, and performance, C–1
SYSTEMID parameter, B–7

T
Tape serving, 1–3
Troubleshooting, 4–1

U
Unit number labels, 2–19, 3–11
Unit number, setting, 3–10
Unit number, setting with set host, 2–19
UNITNUM parameter, B–7
UPS, 1–7

V
VAXcluster software license, 1–5
VMScluster
capabilities, 1–1
restrictions, 1–3, 1–4
VMScluster software license, 1–5
volume shadowing, C–4
Volume shadowing, 1–4

Index–3

How to Order Additional Documentation

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and press 2 for technical assistance.

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DSSI VMScluster
Installation and Troubleshooting Guide
EK–410AB–MG. D01

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