6    Sample Hardware Configurations

This chapter describes some common Available Server and Production Server hardware configurations. For the Available Server configurations, figures containing generic devices are shown first, and then figures with actual devices are shown. For the Production Server configurations, most of the figures contain generic devices. See Chapter 4 for information about connecting devices to a shared SCSI bus and preparing systems and storage shelves.

6.1    Sample Available Server Hardware Configurations

This section describes some common Available Server hardware configurations.

6.1.1    Available Server Configurations that Use Two Systems and One Shared Bus

Figure 6-1 shows a minimum Available Server hardware configuration consisting of two systems, one storage shelf, and one shared SCSI bus.

Figure 6-1:  Two Systems and One Shared Bus

The following sections provide detailed examples of two-system, one-bus configurations.

6.1.1.1    Single-Ended Device Configurations

In the configuration shown in Figure 6-2, the SCSI controllers and the storage shelf are single-ended, narrow devices. There is one single-ended bus between the two terminated Y cables.

Figure 6-2:  Two DEC 3000/500 Systems With PMAZCs and a BA350 Storage Shelf

To create the configuration in Figure 6-2, you need the following hardware:

If you have the same devices as in Figure 6-2, you can create an alternative configuration by putting the BA350 storage shelf at the end of the shared bus. If you use this configuration, keep the internal termination in the BA350 storage shelf to terminate the bus, and use a BC19J cable to connect the two systems.

If you want two BA350 storage shelves in your configuration, use a BN21H or BN21J cable to connect the shelves, as shown in Figure 6-3.

Figure 6-3:  Two DEC 3000/500 Systems With PMAZCs and Two BA350 Shelves

Figure 6-4 shows a configuration consisting of two types of single-ended SCSI controllers and one single-ended storage shelf. This configuration uses a DEC 7000 system, which uses KZMSA XMI-to-SCSI bus adapters. You must use a DWZZA-AA with the KZMSA because the KZMSA does not have removable termination. Therefore, to provide a differential bus for all devices, you must connect SCSI signal converters to each of the single-ended devices.

Figure 6-4:  A DEC 7000 System, a DEC 3000/500 System With a PMAZC, and a BA350 Storage Shelf

To create the configuration in Figure 6-4, you need the following hardware:

6.1.1.2    Differential Device Configuration

Figure 6-5 shows a configuration consisting of two systems and one HSZ40 DEC RAID controller, all differential devices. There is one shared differential SCSI bus between the terminated H885 trilink connector and terminated BN21W-0B Y cable.

Figure 6-5:  Two AlphaServer 8200 Systems and an HSZ40 Unit

To create the configuration in Figure 6-5, you need the following hardware:

6.1.1.3    Single-Ended Device and Differential Device Configurations

Figure 6-6 shows a configuration with two systems with KZPSA differential SCSI adapters and one single-ended storage shelf with an installed DWZZA-VA SCSI signal converter.

Figure 6-6:  Two AlphaServer 2100 Systems and a BA350 Storage Shelf

To create the configuration in Figure 6-6, you need the following hardware:

Figure 6-7 shows a configuration consisting of two systems with single-ended SCSI controllers connected to SCSI signal converters and one differential storage shelf.

Figure 6-7:  Two DEC 7000 Systems and an HSZ40 Unit

To create the configuration in Figure 6-7, you need the following hardware:

6.1.1.4    UltraSCSI Configurations

Figure 6-8 shows two AlphaServer 8200 systems in an Available Server configuration with two HSZ70 DEC RAID controllers. Note that the SCSI bus adapters are KZPSA PCI-to-SCSI adapters. In this figure, the HSZ70s are on the end of the shared SCSI bus.

Figure 6-8:  UltraSCSI Shared Bus With an HSZ70 on the Bus End

To create the configuration in Figure 6-8, you need the following hardware:

Figure 6-9 shows a figure with two AlphaServer 8200 systems in an Available Server configuration with two HSZ70 DEC RAID controllers in the middle of a shared SCSI bus.

Figure 6-9:  HSZ70 in the Middle of an UltraSCSI Shared Bus

To create the configuration in Figure 6-9, you need the following hardware:

6.1.2    Available Server Configurations That Use Two Systems and Two Shared Buses

More complicated Available Server hardware configurations involve two shared buses. DIGITAL recommends that you set up one bus at a time to avoid confusion.

Figure 6-10 shows an ASE with two systems, two shared buses, and a storage shelf on each bus.

Figure 6-10:  Two Systems and Two Shared Buses

Figure 6-11 shows a detailed two-bus configuration that includes two single-ended systems and storage shelves, which are connected to two single-ended buses. The bus formed from the PMAZC modules' port B is shaded to differentiate it from the bus formed from port A.

Figure 6-11:  Two DEC 3000/500 Systems With PMAZCs, Two BA350 Storage Shelves, and Two Shared Buses

To create the configuration shown in Figure 6-11, you need the following hardware:

Figure 6-12 shows a more complicated two-bus configuration. This configuration includes two DEC 7000 systems, two BA350 storage shelves, one at the end of each bus, and six DWZZA-AA signal converters, connected to two shared buses. Attach terminators to the trilink connectors at each end of each differential bus to terminate the differential shared SCSI buses. The shared bus connected to KZMSA channel 1 is shaded to differentiate it from the bus connected to KZMSA channel 0.

Figure 6-12:  Two DEC 7000 Systems, Two BA350 Storage Shelves, and Two Shared Buses

To create the configuration shown in Figure 6-12, you need the following hardware:

6.1.3    Available Server Configurations That Use Three Systems and Two Shared Buses

Figure 6-13 shows an Available Server configuration with three systems, two shared buses, and storage on each bus.

Figure 6-13:  Three Systems and Two Shared Buses

6.1.4    Available Server Configurations That Use Four Systems and Three Shared Buses

Figure 6-14 shows an Available Server configuration with four systems, three shared buses, and a storage shelf on each bus.

Figure 6-14:  Four Systems and Three Shared Buses

6.2    Sample Production Server Hardware Configurations

This section describes some common Production Server hardware configurations. It does not describe all the possible configurations. You can set up any configuration that adheres to the hardware listed in Chapter 2 and the configuration requirements described in Chapter 4.

6.2.1    Understanding the Configuration Diagrams

Most of the figures in this section use generic devices and other components, such as cables and terminators. To set up your configuration, replace a generic device or component with one listed in Chapter 2.

For example, you can replace a member system with any supported system that has the necessary number of peripheral component interconnect (PCI) slots. Because member systems have different numbers of PCI slots, not all systems can be used in every configuration. You can replace a shared storage shelf with an HSZ40 controller or with a BA350 storage shelf that is connected to a SCSI signal converter.

Except for Figure 6-15, the sample configurations in this chapter show redundant MEMORY CHANNEL interconnects and two shared SCSI buses in each available server environment (ASE).

Figure 6-15 shows the parts of a Production Server hardware configuration.

Figure 6-15:  Hardware Configuration Components

Figure 6-15 shows the following:

• Member systems--You can use any combination of member systems listed in Chapter 2. Member systems have different numbers of PCI slots.

• KZPSA adapters--Install KZPSA PCI-to-SCSI adapters in PCI slots to provide member system connections to shared SCSI buses.

• Shared storage shelves--Use any combination of storage shelves listed in Chapter 2. If you have a single-ended storage shelf, such as a BA350, you must connect it to a SCSI signal converter.

• Trilink connectors or Y cables--Use trilink connectors and Y cables to connect KZPSA SCSI adapters, DEC RAID controllers, or SCSI signal converters installed in single-ended storage shelves to shared SCSI buses.

• SCSI differential cables--Use the appropriate cables to connect the trilink connectors and Y cables attached to member systems and storage shelves.

• SCSI terminators--Terminate both ends of each shared SCSI bus.

• MEMORY CHANNEL adapters--Install MEMORY CHANNEL adapters in PCI slots to connect systems to the cluster interconnects.

• MEMORY CHANNEL hub--A MEMORY CHANNEL hub is required if you have more than two member systems. You can install up to eight line cards in a hub.

• MEMORY CHANNEL link cables--Use a MEMORY CHANNEL link cable to connect a MEMORY CHANNEL adapter to another adapter, or to connect an adapter to a line card installed in a hub.

The following sections show some common Production Server hardware configurations.

6.2.2    Production Server Two-Member System Configuration

Figure 6-16 shows a Production Server hardware configuration that includes two member systems, two terminated shared SCSI buses, and redundant MEMORY CHANNEL interconnects in a virtual hub configuration (there is no MEMORY CHANNEL hub).

Figure 6-16:  Two-System Configuration

Figure 6-17 shows an actual example of the previous configuration using the following hardware:

• Two AlphaServer 2100A systems with KZPSA adapters and H885 trilink connectors

• Two BA350 storage shelves with installed DWZZA-VA signal converters and trilink connectors attached to the signal converters

• Two shared SCSI buses consisting of BN21K or BN21L cables that are connected to the trilink connectors and terminated with H879-AA terminators

• Redundant MEMORY CHANNEL adapters connected by MEMORY CHANNEL link cables to form the MEMORY CHANNEL interconnects

Figure 6-17:  Actual Two-System Configuration

6.2.3    Production Server Three-Member System Configuration

Figure 6-18 shows a Production Server hardware configuration that includes three member systems, two terminated shared SCSI buses, and redundant MEMORY CHANNEL interconnects in a standard hub configuration (it uses MEMORY CHANNEL hubs). Because this configuration requires four PCI slots, it is not supported on AlphaServer 2000 or 2100 systems.

Figure 6-18:  Three-System Configuration

6.2.4    Production Server Four-Member System Configurations

A four-system hardware configuration can include either one or two ASEs. Chapter 1 describes the performance and availability benefits of one- and two-ASE configurations.

Figure 6-19 shows a four-member Production Server configuration that consists of one ASE with two shared SCSI buses, and redundant MEMORY CHANNEL interconnects with MEMORY CHANNEL hubs. Because this configuration requires four PCI slots, it is not supported on AlphaServer 2000 or 2100 systems.

Figure 6-19:  Four-System, One-ASE Configuration

Figure 6-20 shows a Production Server hardware configuration with two ASEs. Each ASE consists of two member systems, each connected to two shared SCSI buses. Each member system also has redundant MEMORY CHANNEL interconnects in a standard hub configuration (including MEMORY CHANNEL hubs). Because this configuration requires four PCI slots, it is not supported on AlphaServer 2000 or 2100 systems.

Figure 6-20:  Four-System, Two-ASE Configuration