10    Configurations Using External Termination or Radial Connections to Non-UltraSCSI Devices

This chapter describes the requirements for the shared SCSI bus using:

In addition to using only the supported hardware, adhering to the requirements described in this chapter will ensure that your cluster operates correctly.

This chapter discusses the following topics:

Introductory information covering SCSI bus configuration concepts (SCSI bus speed, data path, and so on) and SCSI bus configuration requirements can be found in Chapter 3.

10.1    Using SCSI Bus Signal Converters

A SCSI bus signal converter allows you to couple a differential bus segment to a single-ended bus segment, allowing the mixing of differential and single-ended devices on the same SCSI bus to isolate bus segments for maintenance purposes.

Each SCSI signal converter has a single-ended side and a differential side as follows:

Note

Some UltraSCSI documentation uses the UltraSCSI term bus expander when referring to the DWZZB and UltraSCSI signal converters. Other UltraSCSI documentation refers to some UltraSCSI products as bus extender/converters.

For TruCluster Server there are no supported standalone UltraSCSI bus expanders (DWZZC).

In this manual, any device that converts a differential signal to a single-ended signal is referred to as a signal converter (the DS-BA35X-DA personality module contains a DWZZA-on-a-chip or DOC chip).

A SCSI signal converter is required when you want to connect devices with different transmission modes.

10.1.1    Types of SCSI Bus Signal Converters

Signal converters can be standalone units or StorageWorks building blocks (SBBs) that are installed in a storage shelf disk slot. You must use the signal converter module that is appropriate for your hardware configuration.

For example, use a DWZZA-VA signal converter to connect a wide, differential host bus adapter to a BA350 (single-ended and narrow) storage shelf, but use a DWZZB-VW signal converter to connect a wide, differential host bus adapter to a non-UltraSCSI BA356 (single-ended and wide) storage shelf. The DS-BA35X-DA personality module is used in an UltraSCSI BA356 to connect an UltraSCSI host bus adapter to the single-ended disks in the UltraSCSI BA356. You can install a DWZZB-VW in an UltraSCSI BA356, but you will waste a disk slot and it will not work with a KZPBA-CB if there are any UltraSCSI disks in the storage shelves.

The following sections discuss the DWZZA and DWZZB signal converters and the DS-BA35X-DA personality module.

10.1.2    Using the SCSI Bus Signal Converters

The DWZZA and DWZZB signal converters are used in the BA350 and BA356 storage shelves. They have removable termination. The DS-BA35X-DA personality module is used in the UltraSCSI BA356. It has switch selectable differential termination. The single-ended termination is active termination.

The following sections describe termination for these signal converters in more detail.

10.1.2.1    DWZZA and DWZZB Signal Converter Termination

Both the single-ended side and the differential side of each DWZZA and DWZZB signal converter have removable termination. To use a signal converter, you must remove the termination in the differential side and attach a trilink connector to this side. To remove the differential termination, remove the five 14-pin termination resistor SIPs (located near the differential end of the signal converter). You can attach a terminator to the trilink connector to terminate the differential bus. If you detach the trilink connector from the signal converter, the shared SCSI bus is still terminated (provided there is termination power).

You must keep the termination in the single-ended side to provide termination for one end of the BA350 or BA356 single-ended SCSI bus segment. Verify that the termination is active. A DWZZA should have jumper J2 installed. Jumpers W1 and W2 should be installed in a DWZZB.

Figure 10-1 shows the status of internal termination for a standalone SCSI signal converter that has a trilink connector attached to the differential side.

Figure 10-1:  Standalone SCSI Signal Converter

Figure 10-2 shows the status of internal termination for an SBB SCSI signal converter that has a trilink connector attached to the differential side.

Figure 10-2:  SBB SCSI Signal Converter

10.1.2.2    DS-BA35X-DA Termination

The UltraSCSI BA356 shelf uses a 16-bit differential UltraSCSI personality module (DS-BA35X-DA) as the interface between the UltraSCSI differential bus and the UltraSCSI single-ended bus in the UltraSCSI BA356.

The personality module controls termination for the external differential UltraSCSI bus segment, and for both ends of the internal single-ended bus segment.

For normal cluster operation, the differential termination must be disabled since a trilink connector will be installed on personality module connector JA1, allowing the use of the UltraSCSI BA356 (or two UltraSCSI BA356s) in the middle of the bus or external termination for an UltraSCSI BA356 on the end of the bus.

Switch pack 4 switches S4-1 and S4-2 are set to ON to disable the personality module differential termination. The switches have no effect on the BA356 internal, single-ended UltraSCSI bus termination.

Notes

S4-3 and S4-4 have no function on the DS-BA35X-DA personality module.

See Section 10.3.2.2 for information on how to select the device SCSI IDs in an UltraSCSI BA356.

Figure 10-3 shows the relative positions of the two DS-BA35X-DA switch packs.

Figure 10-3:  DS-BA35X-DA Personality Module Switches

10.2    Terminating the Shared SCSI Bus

You must properly connect devices to a shared SCSI bus. In addition, you can terminate only the beginning and end of each SCSI bus segment (either single-ended or differential).

There are two rules for SCSI bus termination:

Whenever possible, connect devices to a shared bus so that they can be isolated from the bus. This allows you to disconnect devices from the bus for maintenance purposes without affecting bus termination and cluster operation. You also can set up a shared SCSI bus so that you can connect additional devices at a later time without affecting bus termination.

Notes

With the exception of the TZ885, TZ887, TL890, TL891, and TL892, tape devices can only be installed at the end of a shared SCSI bus. These tape devices are the only supported tape devices that can be terminated externally.

We recommend that tape loaders be on a separate shared SCSI bus to allow normal shared SCSI bus termination for those shared SCSI buses without tape loaders.

Most devices have internal termination. For example, the KZPSA and KZPBA host bus adapters, BA350 and BA356 storage shelves, and the DWZZA and DWZZB SCSI bus signal converters have internal termination. Depending on how you set up a shared bus, you may have to enable or disable device termination.

Unless you are using an UltraSCSI hub, if you use a device's internal termination to terminate a shared bus, and you disconnect the bus cable from the device, the bus will not be terminated and cluster operation will be impaired. Therefore, unless you use an UltraSCSI hub, you must use external termination, enabling you to detach the device without affecting bus termination. The use of UltraSCSI hubs with UltraSCSI devices is discussed in Section 3.5 and Section 3.6. The use of a DS-DWZZH-03 UltraSCSI hub with externally terminated host bus adapters is discussed in Section 10.4.4.

To be able to externally terminate a bus and connect and disconnect devices without affecting bus termination, remove the device termination and use Y cables or trilink connectors to connect a device to a shared SCSI bus.

By attaching a Y cable or trilink connector to an unterminated device, you can locate the device in the middle or at the end of the shared bus. If the device is at the end of a bus, attach an H879-AA terminator to the BN21W-0B Y cable or H885-AA trilink connector to terminate the bus. For UltraSCSI devices, attach an H8863-AA terminator to the H8861 trilink connector. If you disconnect the Y cable or trilink connector from the device, the shared bus is still terminated and the shared SCSI bus is still operable.

In addition, you can attach a Y cable or a trilink connector to a properly terminated shared bus without connecting the Y cable or trilink connector to a device. If you do this, you can connect a device to the Y cable or trilink connector at a later time without affecting bus termination. This allows you to expand your configuration without shutting down the cluster.

Figure 10-4 shows a BN21W-0B Y cable, which you may attach to a KZPSA-BB or KZPBA-CB SCSI adapter that has had its onboard termination removed. You can also use the BN21W-0B Y cable with a HSZ40 or HSZ50 controller or the unterminated differential side of a SCSI signal converter.

Note

You will normally use a Y cable on a KZPSA-BB or KZPBA-CB host bus adapter where there is not room for an H885-AA trilink, and a trilink connector elsewhere.

Figure 10-4:  BN21W-0B Y Cable

Figure 10-5 shows an HD68 trilink connector (H885-AA), which you may attach to a KZPSA-BB or KZPBA-CB adapter that has its onboard termination removed, an HSZ40 or HSZ50 controller, or the unterminated differential side of a SCSI signal converter.

Figure 10-5:  HD68 Trilink Connector (H885-AA)

Note

If you connect a trilink connector to a SCSI bus adapter, you may block access to an adjacent PCI slot. If this occurs, use a Y cable instead of the trilink connector. This is the case with the KZPBA-CB and KZPSA-BB SCSI adapters on some AlphaServer systems.

Use the H879-AA terminator to terminate one leg of a BN21W-0B Y cable or H885-AA trilink.

Use an H8861-AA VHDCI trilink connector (see Figure 3-1) with a DS-BA35X-DA personality module to daisy chain two UltraSCSI BA356s or to terminate external to the UltraSCSI BA356 storage shelf. Use the H8863-AA VHDCI terminator with the H8861-AA trilink connector.

10.3    Overview of Disk Storage Shelves

The following sections provide an introduction to the BA350, BA356, and UltraSCSI BA356 disk storage shelves.

10.3.1    BA350 Storage Shelf

Up to seven narrow (8-bit) single-ended StorageWorks building blocks (SBBs) can be installed in the BA350. Their SCSI IDs are based upon the slot they are installed in. For instance, a disk installed in BA350 slot 0 has SCSI ID 0, a disk installed in BA350 slot 1 has SCSI ID 1, and so forth.

Note

Do not install disks in the slots corresponding to the host SCSI IDs (usually SCSI ID 6 and 7 for a two-node cluster).

You use a DWZZA-VA as the interface between the wide, differential shared SCSI bus and the BA350 narrow, single-ended SCSI bus segment.

Note

Do not use a DWZZB-VW in a BA350. The use of the wide DWZZB-VW on the narrow single-ended bus will result in unterminated data lines in the DWZZB-VW, which will cause SCSI bus errors.

The BA350 storage shelf contains internal SCSI bus termination and a SCSI bus jumper. The jumper is not removed during normal operation.

The BA350 can be set up for two-bus operation, but that option is not very useful for a shared SCSI bus and is not covered in this manual.

Figure 10-6 shows the relative locations of the BA350 SCSI bus terminator and SCSI bus jumper. They are accessed from the rear of the box. For operation within a TruCluster Server cluster, both the J jumper and T terminator must be installed.

Figure 10-6:  BA350 Internal SCSI Bus

10.3.2    BA356 Storage Shelf

There are two variations of the BA356 used in TruCluster Server clusters: the BA356 (non-UltraSCSI BA356) and the UltraSCSI BA356.

An example of the non-UltraSCSI BA356 is the BA356-KC, which has a wide, single-ended internal SCSI bus. It has a BA35X-MH 16-bit personality module (only used for SCSI ID selection) and a 150-watt power supply. It is referred to as the non-UltraSCSI BA356 or BA356 in this manual. You use a DWZZB-VW as the interface between the wide, differential shared SCSI bus and the BA356 wide, single-ended SCSI bus segment.

10.3.2.1    Non-UltraSCSI BA356 Storage Shelf

The non-UltraSCSI BA356, like the BA350, can hold up to seven StorageWorks building blocks (SBBs). However, unlike the BA350, these SBBs are wide devices and can therefore support up to 16 disks (in two BA356 shelves). Also, like the BA350, the SBB SCSI IDs are based upon the slot they are installed in. The switches on the personality module (BA35X-MH) determine whether the disks respond to SCSI IDs 0 through 6 (slot 7 is the power supply) or 8 through 14 (slot 15 is the power supply). To select SCSI IDs 0 through 6, set the personality module address switches 1 through 7 to off. To select SCSI IDs 8 through 14, set personality module address switches 1 through 3 to on and switches 4 through 7 to off.

Figure 10-7 shows the relative location of the BA356 SCSI bus jumper, BA35X-MF. The jumper is accessed from the rear of the box. For operation within a TruCluster Server cluster, you must install the J jumper in the normal position, behind slot 6. The SCSI bus jumper is not in the same position in the BA356 as in the BA350.

Termination for the BA356 single-ended bus is on the personality module, and is active unless a cable is installed on JB1 to daisy chain the single-ended SCSI bus in two BA356 storage shelves together. In this case, when the cable is connected to JB1, the personality module terminator is disabled.

Daisy chaining the single-ended bus between two BA356s is not used in clusters. We use DWZZB-VWs (with an attached H885-AA trilink connector) in each BA356 to connect the wide-differential connection from the host adapters to both BA356s in parallel. The switches on the personality module of one BA356 are set for SCSI IDs 0 through 7 and the switches on the personality module of the other BA356 are set for SCSI IDs 8 through 14.

Note

Do not install a narrow disk in a BA356 that is enabled for SCSI IDs 8 through 14. The SCSI bus will not operate correctly because the narrow disks cannot recognize wide addresses.

Like the BA350, you can set up the BA356 for two-bus operation by installing a SCSI bus terminator (BA35X-ME) in place of the SCSI bus jumper. However, like the BA350, two-bus operation in the BA356 is not very useful for a TruCluster Server cluster.

You can use the position behind slot 1 in the BA356 to store the SCSI bus terminator or jumper.

Figure 10-7 shows the relative locations of the BA356 SCSI bus jumper and the position for storing the SCSI bus jumper, if you do install the terminator. For operation within a TruCluster Server cluster, you must install the J jumper.

Figure 10-7:  BA356 Internal SCSI Bus

JA1 and JB1 are located on the personality module (in the top of the box when it is standing vertically). JB1, on the front of the module, is visible. JA1 is on the left side of the personality module as you face the front of the BA356, and is hidden from the normal view.

To determine if a jumper module or terminator module is installed in a BA356, remove the devices from slots 1 and 6 and note the following pin locations (see Figure 10-8):

Figure 10-8:  BA356 Jumper and Terminator Module Identification Pins

10.3.2.2    UltraSCSI BA356 Storage Shelf

The UltraSCSI BA356 (DS-BA356-JF or DS-BA356-KH) has a single-ended, wide UltraSCSI bus. The DS-BA35X-DA personality module provides the interface between the internal, single-ended UltraSCSI bus segment and the shared, wide, differential UltraSCSI bus. The UltraSCSI BA356 uses a 180-watt power supply.

An older, non-UltraSCSI BA356 that has been retrofitted with a BA35X-HH 180-watt power supply and DS-BA35X-DA personality module is still only FCC certified for Fast 10 configurations. (See Section 3.2.4 for a discussion on bus speed.)

The UltraSCSI BA356 can hold up to seven StorageWorks building blocks (SBBs). These SBBs are UltraSCSI single-ended wide devices. The disk SCSI IDs are based upon the slot they are installed in. The S3 switches on the personality module (DS-BA35X-DA) determine whether the disks respond to SCSI IDs 0 through 6 (slot 7 is the power supply) or 8 through 14 (slot 15 is the power supply). To select SCSI IDs 0 through 6, set switches S3-1 through S3-7 to off. To select SCSI IDs 8 through 14, set personality module address switches S3-1 through S3-3 to on and switches S3-4 through S3-7 to off.

The jumper module is positioned behind slot 6 as with the non-UltraSCSI BA356 shown in Figure 10-7. For operation within a TruCluster Server cluster, you must install the J jumper. You verify the presence or absence of the jumper or terminator modules in the same manner as for the non-UltraSCSI BA356, as shown in Figure 10-8. With proper lighting you will be able to see a J or T near the hole where the pin sticks through.

Termination for both ends of the UltraSCSI BA356 internal, single-ended bus is on the personality module, and is always active. Termination for the differential UltraSCSI bus is also on the personality module, and is controlled by the SCSI bus termination switches, switch pack S4. DS-BA35X-DA termination is discussed in Section 10.1.2.2.

10.4    Preparing the Storage for Configurations Using External Termination

A TruCluster Server cluster provides you with high data availability through the cluster file system (CFS), the device request dispatcher, service failover through the cluster application availability (CAA) subsystem, disk mirroring, and fast file system recovery. TruCluster Server supports mirroring of the member-specific boot disks and the cluster quorum disk through hardware RAID only. You can mirror the clusterwide root (/), /usr and /var file systems, the data disks, and the swap file system using the Logical Storage Manager (LSM) technology. You must determine the storage configuration that will meet your needs. Mirroring disks across two shared buses provides the most highly available data.

Disk devices used on the shared bus must be located in a supported storage shelf. Before you connect a storage shelf to a shared SCSI bus, you must install the disks in the unit. Before connecting a RAID array controller to a shared SCSI bus, install the disks and configure the storagesets. For detailed information about installation and configuration, see your storage shelf (or RAID array controller) documentation.

The following sections describe how to prepare storage for a shared SCSI bus and external termination for:

If you need to use a BA350 or non-UltraSCSI BA356 with an UltraSCSI BA356 storage shelve, extrapolate the needed information from Section 10.4.1 and Section 10.4.3.

Later sections describe how to install cables to configure an HSZ20, HSZ40, or HSZ50 in a TruCluster Server configuration with two member systems.

10.4.1    Preparing BA350, BA356, and UltraSCSI BA356 Storage Shelves for an Externally Terminated TruCluster Server Configuration

You may be using the BA350, BA356, or UltraSCSI BA356 storage shelves in your TruCluster Server configuration as follows:

The following sections discuss the steps necessary to prepare the individual storage shelves, and then connect two storage shelves together to provide the additional storage.

Note

This material has been written with the premise that there are only two member systems in any TruCluster Server configuration using direct connect disks for storage. Using this assumption, and further assuming that the member systems use SCSI IDs 6 and 7, the storage shelf housing disks in the range of SCSI IDs 0 through 6 can only use SCSI IDs 0 through 5.

If there are more than two member systems, additional disk slots will be needed to provide the additional member system SCSI IDs.

10.4.1.1    Preparing a BA350 Storage Shelf for Shared SCSI Usage

To prepare a BA350 storage shelf for usage on a shared SCSI bus, follow these steps:

  1. Ensure that the BA350 storage shelf's internal termination and jumper is installed (see Section 10.3.1 and Figure 10-6).

  2. You will need a DWZZA-VA signal converter for the BA350. Ensure that the DWZZA-VA single-ended termination jumper, J2, is installed. Remove the termination from the differential end by removing the five 14-pin differential terminator resistor SIPs.

  3. Attach an H885-AA trilink connector to the DWZZA-VA 68-pin high-density connector.

  4. Install the DWZZA-VA in slot 0 of the BA350.

10.4.1.2    Preparing a BA356 Storage Shelf for Shared SCSI Usage

To prepare a BA356 storage shelf for shared SCSI bus usage, follow these steps:

  1. You need either a DWZZB-AA or DWZZB-VW signal converter. The DWZZB-VW is more commonly used. Verify signal converter termination as follows:

  2. Attach an H885-AA trilink connector to the DWZZB 68-pin high-density connector.

  3. Set the switches on the BA356 personality module as follows:

    If you are using a DWZZB-AA, do not replace the personality module until you attach the cable in the next step.

  4. If you are using a DWZZB-AA signal converter, use a BN21K-01 (1-meter; 3.3-foot) or BN21L-01 (1-meter; 3.3-foot) cable to connect the single-ended side of the DWZZB-AA to the BA356 input connector, JA1, on the personality module. Connector JA1 is on the left side of the personality module as you face the front of the BA356, and is hidden from normal view. This connection forms a single-ended bus segment that is terminated by the DWZZB single-ended termination and the BA356 termination on the personality module. The use of a 1-meter (3.3-foot) cable keeps the single-ended SCSI bus (cable and BA356) under the 3-meter (9.8-foot) limit to still allow high speed operation.

    If you are using a DWZZB-VW, install it in slot 0 of the BA356.

10.4.1.3    Preparing an UltraSCSI BA356 Storage Shelf for a TruCluster Configuration

An UltraSCSI BA356 storage shelf is connected to a shared UltraSCSI bus, and provides access to UltraSCSI devices on the internal, single-ended and wide UltraSCSI bus. The interface between the buses is the DS-BA35X-DA personality module installed in the UltraSCSI BA356.

To prepare an UltraSCSI BA356 storage shelf for usage on a shared SCSI bus, follow these steps:

  1. Ensure that the BA35X-MJ jumper module is installed behind slot 6 (see Section 10.3.2.1, Figure 10-7, and Figure 10-8).

  2. Set the SCSI bus ID switches on the UltraSCSI BA356 personality module (DS-BA35X-DA, Figure 10-3) as follows:

  3. Disable the UltraSCSI BA356 differential termination. Ensure that personality module (DS-BA35X-DA) switch pack 4 switches S4-1 and S4-2 are ON (see Figure 10-3).

    Note

    S4-3 and S4-4 are not used on the DS-BA35X-DA.

  4. Install an H8861-AA VHDCI trilink connector on the UltraSCSI BA356 personality module.

10.4.2    Cabling a Single Storage Shelf

A cluster with a single storage shelf is generally of little use because of the lack of disk space. But, for those customers whose primary use of the cluster is the Memory Channel application programming interface (API), storage is not an issue; they only need a shared SCSI bus to fulfill the TruCluster Server requirements. Therefore, there are no illustrations in this section showing clusters with single storage shelves. The illustrations in Section 10.4.3 can be used with the descriptions in this section.

10.4.2.1    Cabling a Single BA350 Storage Shelf

To cable a single BA350 storage shelf into a cluster, install a BN21K, BN21L, or 328215-00X HD68 cable between the BN21W-0B Y cable on the host bus adapter of each system and the H885-AA trilink connector installed on the DWZZA-VA installed in slot 0 of the BA350. See the left-half of Figure 10-9.

10.4.2.2    Cabling a Single BA356 Storage Shelf

To cable a single BA356 storage shelf into a cluster, install a BN21K, BN21L, or 328215-00X HD68 cable between the BN21W-0B Y cable on the host bus adapter of each system and the H885-AA trilink connector installed on the DWZZB-VW installed in slot 0 of the BA356. See Figure 10-10.

10.4.2.3    Cabling a Single UltraSCSI BA356 Storage Shelf

To cable a single UltraSCSI BA356 storage shelf into a cluster, connect a BN38C, BN38D, or combination of a BN38E-0B technology adapter cable and a BN37A cable between the BN21W-0B Y cable on each system and H8861-AA VHDCI trilink connector on the UltraSCSI BA356 personality module. See Figure 10-11.

10.4.3    Connecting Storage Shelves Together

Section 10.4.1 covered the steps necessary to prepare the BA350, BA356, and UltraSCSI BA356 storage shelves for use on a shared SCSI bus. However, you will probably need more storage than one storage shelf can provide, so you will need two storage shelves on the shared SCSI bus.

Note

Because the BA350 contains a narrow (8-bit), single-ended SCSI bus, it only supports SCSI IDs 0 through 7. Therefore, a BA350 must be used with a BA356 or UltraSCSI BA356 if more than five disks are required.

The following sections provide the steps needed to connect two storage shelves and two member systems on a shared SCSI bus:

10.4.3.1    Connecting a BA350 and a BA356 for Shared SCSI Bus Usage

When you use a BA350 and a BA356 for storage on a shared SCSI bus in a TruCluster Server configuration, the BA356 must be configured for SCSI IDs 8 through 14.

To prepare a BA350 and BA356 for shared SCSI bus usage (see Figure 10-9), follow these steps:

  1. Complete the steps in Section 10.4.1.1 and Section 10.4.1.2 to prepare the BA350 and BA356. Ensure that the BA356 is configured for SCSI IDs 8 through 14.

  2. If either storage shelf will be at the end of the shared SCSI bus, attach an H879-AA terminator to the H885-AA trilink on the DWZZA or DWZZB for the storage shelf that will be at the end of the bus. You can choose either storage shelf to be on the end of the bus.

  3. Connect a BN21K or BN21L between the H885-AA trilink on the DWZZA (BA350) and the H885-AA trilink on the DWZZB (BA356)

  4. When the KZPSA-BB or KZPBA-CB host bus adapters have been installed:

Figure 10-9 shows a two-member TruCluster Server configuration using a BA350 and a BA356 for storage.

Figure 10-9:  BA350 and BA356 Cabled for Shared SCSI Bus Usage

Table 10-1 lists the components that are used to create the cluster that is shown in Figure 10-9 and Figure 10-10.

Table 10-1:  Hardware Components Used for Configuration Shown in Figure 10-9 and Figure 10-10

Callout Number Description
1 BN21W-0B Y cable
2 H879-AA terminator
3 BN21K, BN21L, or 328215-00X cable [Footnote 67]
4 H885-AA trilink connector

10.4.3.2    Connecting Two BA356s for Shared SCSI Bus Usage

When you use two BA356 storage shelves on a shared SCSI bus in a TruCluster configuration, one BA356 must be configured for SCSI IDs 0 through 6 and the other configured for SCSI IDs 8 through 14.

To prepare two BA356 storage shelves for shared SCSI bus usage (see Figure 10-10), follow these steps:

  1. Complete the steps of Section 10.4.1.2 for each BA356. Ensure that the personality module address switches on one BA356 are set to select SCSI IDs 0 through 6, and that the address switches on the other BA356 personality module are set to select SCSI IDs 8 through 14.

  2. If either of the BA356 storage shelves will be on the end of the SCSI bus, attach an H879-AA terminator to the H885-AA trilink on the DWZZB for the BA356 that will be on the end of the bus.

  3. Connect a BN21K or BN21L cable between the H885-AA trilinks.

  4. When the KZPSA-BB or KZPBA-CB host bus adapters have been installed:

Figure 10-10 shows a two member TruCluster Server configuration using two BA356s for storage.

Figure 10-10:  Two BA356s Cabled for Shared SCSI Bus Usage

Table 10-1 lists the components that are used to create the cluster that is shown in Figure 10-10.

10.4.3.3    Connecting Two UltraSCSI BA356s for Shared SCSI Bus Usage

When you use two UltraSCSI BA356 storage shelves on a shared SCSI bus in a TruCluster configuration, one storage shelf must be configured for SCSI IDs 0 through 6 and the other configured for SCSI IDs 8 through 14.

To prepare two UltraSCSI BA356 storage shelves for shared SCSI bus usage (see Figure 10-11), follow these steps:

  1. Complete the steps of Section 10.4.1.3 for each UltraSCSI BA356. Ensure that the personality module address switches on one UltraSCSI BA356 are set to select SCSI IDs 0 through 6 and the address switches on the other UltraSCSI BA356 personality module are set to select SCSI IDs 8 through 14.

  2. You will need two H8861-AA VHDCI trilink connectors. If either of the UltraSCSI BA356 storage shelves will be on the end of the SCSI bus, attach an a H8863-AA terminator to one of the H8861-AA trilink connectors. Install the trilink with the terminator on connector JA1 of the DS-BA35X-DA personality module of the UltraSCSI BA356 that will be on the end of the SCSI bus. Install the other H8861-AA trilink on JA1 of the DS-BA35X-DA personality module of the other UltraSCSI BA356.

  3. Connect a BN37A VHDCI to VHDCI cable between the H8861-AA trilink connectors on the UltraSCSI BA356s.

  4. When the KZPSA-BBs or KZPBA-CBs are installed:

Figure 10-11 shows a two member TruCluster Server configuration using two UltraSCSI BA356s for storage.

Figure 10-11:  Two UltraSCSI BA356s Cabled for Shared SCSI Bus Usage

Table 10-2 lists the components that are used to create the cluster that is shown in Figure 10-11.

Table 10-2:  Hardware Components Used for Configuration Shown in Figure 10-11

Callout Number Description
1 BN21W-0B Y cable
2 H879-AA HD68 terminator
3 BN38C (or BN38D) cable [Footnote 68] [Footnote 69]
4 H8861-AA VHDCI trilink connector
5 BN37A cable [Footnote 69]

10.4.4    Cabling a Non-UltraSCSI RAID Array Controller to an Externally Terminated Shared SCSI Bus

A RAID array controller provides high performance, high availability, and high connectivity access to SCSI devices through the shared SCSI buses.

Before you connect a RAID controller to a shared SCSI bus, you must install and configure the disks that the controller will use, and ensure that the controller has a unique SCSI ID on the shared bus.

You can configure the HSZ20, HSZ40, and HSZ50 RAID array controllers with one to four SCSI IDs.

Because the HSZ20, HSZ40, and HSZ50 have a wide differential connection on the host side, you connect them to one of the following differential devices:

Note

The HSZ20, HSZ40, and HSZ50 cannot operate at UltraSCSI speeds when used with the KZPBA-CB.

You can also use a DS-DWZZH-03 or DS-DWZZH-05 UltraSCSI hub with one of these RAID array controllers and either the KZPSA-BB or KZPBA-CB host bus adapters. UltraSCSI cables are required to make the connection to the hub. UltraSCSI speed is not supported with these RAID array controllers when used with a hub and the KZPBA-CB host bus adapter.

10.4.4.1    Cabling an HSZ40 or HSZ50 in a Cluster Using External Termination

To connect an HSZ40 or HSZ50 controller to an externally terminated shared SCSI bus, follow these steps:

  1. If the HSZ40 or HSZ50 will be on the end of the shared SCSI bus, attach an H879-AA terminator to an H885-AA trilink connector.

  2. Attach an H885-AA trilink connector to each RAID controller port. Attach the H885-AA trilink connector with the terminator to the controller that will be on the end of the shared SCSI bus.

  3. If you are using dual-redundant RAID array controllers, install a BN21-K or BN21L cable (a BN21L-0B is a 15-centimeter (5.9-inch) cable) between the H885-AA trilink connectors on the controllers.

  4. When the host bus adapters (KZPSA-BB or KZPBA-CB) have been installed, connect the host bus adapters and RAID array controllers together with BN21K or BN21L cables as follows:

Figure 10-12 shows two AlphaServer systems in a TruCluster Server configuration with dual-redundant HSZ50 RAID controllers in the middle of the shared SCSI bus. Note that the SCSI bus adapters are KZPSA-BB PCI-to-SCSI adapters. They could be KZPBA-CB host bus adapters without changing any cables.

Figure 10-12:  Externally Terminated Shared SCSI Bus with Mid-Bus HSZ50 RAID Array Controllers

Table 10-3 lists the components that are used to create the cluster that is shown in Figure 10-12 and Figure 10-13.

Figure 10-13 shows two AlphaServer systems in a TruCluster Server configuration with dual-redundant HSZ50 RAID controllers at the end of the shared SCSI bus. As with Figure 10-12, the SCSI bus adapters are KZPSA-BB PCI-to-SCSI adapters. They could be KZPBA-CB host bus adapters without changing any cables.

Figure 10-13:  Externally Terminated Shared SCSI Bus with HSZ50 RAID Array Controllers at Bus End

Table 10-3 lists the components that are used to create the cluster that is shown in Figure 10-12 and Figure 10-13.

Table 10-3:  Hardware Components Used for Configuration Shown in Figure 10-12 and Figure 10-13

Callout Number Description
1 BN21W-0B Y cable
2 H879-AA terminator
3 BN21K (or BN21L) cable [Footnote 70] [Footnote 71]
4 H885-AA trilink connector

10.4.4.2    Cabling an HSZ20 in a Cluster Using External Termination

To connect a SWXRA-Z1 (HSZ20 controller) to a shared SCSI bus, follow these steps:

  1. Referring to the RAID Array 310 Deskside Subsystem (SWXRA-ZX) Hardware User's Guide, open the SWXRA-Z1 cabinet, locate the SCSI bus converter board, and:

  2. Attach an H885-AA trilink connector to the SCSI input connector (on the back of the cabinet).

  3. Use a BN21K or BN21L cable to connect the trilink connector to a trilink connector or BN21W-0B Y cable attached to a differential SCSI controller, another storage shelf, or the differential end of a signal converter.

  4. Terminate the differential bus by attaching an H879-AA terminator to the H885-AA trilink connector or BN21W-0B Y cable at each end of the shared SCSI bus.

    Ensure that all devices that make up the shared SCSI bus are connected, and that there is a terminator at each end of the shared SCSI bus.

10.4.5    Cabling an RA3000 Using External Termination

The RAID Array 3000 (RA3000) is a low-end, standalone UltraSCSI RAID subsystem. It supports RAID levels 0, 1, 0+1, 4, 5, and JBOD disks.

The RA3000 storage subsystem has fully redundant components to eliminate single points of failure. It comes with a standard uninterruptible power supply (UPS) for cache data protection during power outages.

The RA3000 uses the dual-ported HSZ22 controller. Optional dual redundant controllers with mirrored write-back cache provide maximum data integrity.

For more information on the RA3000, see Section 3.7.1.3.

Note

The RA3000 is supported on a shared SCSI bus only with the KZPBA-CB UltraSCSI host bus adapter.

Table 10-4 provides the steps necessary to connect TruCluster Server member systems to an RA3000 storage subsystem using external termination and Y cables.

Table 10-4:  Installing Cables for RA3000 Configuration Using External Termination and Y Cables

Action Refer to:
Install SCSI bus cables:  
RA3000 pedestal with active/passive failover: Install a BN38C HD68 to VHDCI cable between the BN21W-0B Y cable of one member system and the RA3000 Host 0 port. [Footnote 72] Figure 10-14
Install a BN21K, BN21L, or BN31G cable between the BN21W-0B Y cables of all other member systems. [Footnote 73] --
RA3000 controller shelf with active/passive failover: Install a BN38C HD68 to VHDCI cable between the BN21W-0B Y cable of one member system and the RA3000 Host 0 I/O module Host In port. [Footnote 72] Figure 10-15
Install a BN21K, BN21L, or BN31G cable between the BN21W-0B Y cables of all other member systems. [Footnote 73] --
RA3000 controller shelf with active/active or active/passive failover: Install a BN38C HD68 to VHDCI cable between the BN21W-0B Y cable of one member system and the RA3000 Host 0 I/O module Host In connection. [Footnote 72] Figure 10-16
Install a BN37A-0E 50-centimeter (19.7-inch) VHDCI cable between the RA3000 controller shelf Host 0 I/O module Host Out port and the Host 1 I/O module Host In port. --
Install a BN21K, BN21L, or BN31G cable between the BN21W-0B Y cables of all other member systems. [Footnote 73] --
RA3000 mid-bus controller shelf with active/active or active/passive failover: Install a BN38C HD68 to VHDCI cable between the BN21W-0B Y cable of one member system and the RA3000 Host 0 I/O module Host In connection. Install a second BN38C HD68 to VHDCI cable between the BN21W-0B Y cable of another member system and the RA3000 Host 1 I/O module Host Out connection. This disables the termination on the Host 1 I/O module. [Footnote 72] Figure 10-17
Install a BN37A-0E 50-centimeter (19.7-inch) VHDCI cable between the RA3000 controller shelf Host 0 I/O module Host Out port and the Host 1 I/O module Host In port. The connection to Host 0 I/O module Host Out port disables the termination on that Host I/O module. --
Install a BN21K, BN21L, or BN31G cable between the BN21W-0B Y cables of any other member systems. [Footnote 73] --

Note

You cannot create a mid-bus configuration using a RA3000 pedestal. The member systems on one SCSI bus segment connected to the Host 0 port would see some devices. The member systems on the other SCSI bus segment connected to the Host 1 port would not be able to see the same devices.

Figure 10-14 (pedestal) and Figure 10-15 (controller shelf) show an externally terminated TruCluster Server configuration using an RA3000. The RA3000 controller shelf and pedestal contains internal termination. Table 10-5 lists the components used to create the clusters shown in Figure 10-14, Figure 10-15, and Figure 10-16.

Figure 10-14:  Externally Terminated TruCluster Server Configuration with an RA3000 Pedestal with Active/Passive Failover

Figure 10-15:  Externally Terminated TruCluster Server Configuration with an RA3000 Controller Shelf with Active/Passive Failover

Figure 10-16 shows an externally terminated TruCluster Server configuration using an RA3000 controller shelf. In this configuration, because the Host 0 I/O module is daisy-chained to Host 1 I/O module, dual HSZ22 controllers could use active/active or active/passive failover.

Figure 10-16:  Externally Terminated TruCluster Server Configuration with an RA3000 Controller Shelf with Active/Active or Active/Passive Failover

Table 10-5 lists the components used to create the clusters shown in Figure 10-14, Figure 10-15, and Figure 10-16.

Table 10-5:  Hardware Components Used in the TruCluster Server Configuration Shown in Figure 10-14, Figure 10-15, and Figure 10-16

Callout Number Description
1 H879-AA terminator
2 BN21W-0B Y cable
3 BN21K (BN21L or BN31G) HD68 cable [Footnote 74]
4 BN38C HD68 to VHDCI cable [Footnote 74]
5 BN37A-0E 50-centimeter (19.7-inch) VHDCI cable [Footnote 75]

Figure 10-17 shows an externally terminated TruCluster Server configuration with a RA3000 controller shelf in the middle of the shared SCSI bus. In this configuration, because the Host 0 I/O module is daisy-chained to the Host 1 I/O module, dual HSZ22 controllers could use active/active or active/passive failover.

Figure 10-17:  Externally Terminated TruCluster Server Configuration with a Mid-bus RA3000 Controller Shelf with Active/Active or Active/Passive Failover

Table 10-6 lists the components used to create the cluster shown in Figure 10-17.

Table 10-6:  Hardware Components Used in the Configuration Shown in Figure 10-17

Callout Number Description
1 H879-AA terminator
2 BN21W-0B Y cable
3 BN38C HD68 to VHDCI cable [Footnote 76]
4 BN37A-0E 50-centimeter (19.7-inch) VHDCI cable [Footnote 72]

10.5    Cabling an HSZ40 or HSZ50 RAID Array Controller in a Radial Configuration with an UltraSCSI Hub

You may have an HSZ40 or HSZ50 that you want to keep when you upgrade to a newer AlphaServer system. You can connect an HSZ40 or HSZ50 to an UltraSCSI hub in a radial configuration, but even if the host bus adapter is a KZPBA-CB, it will not operate at UltraSCSI speed with the HSZ40 or HSZ50.

To configure a dual-redundant HSZ40 or HSZ50 RAID array controller and an UltraSCSI hub in a radial configuration, follow these steps:

  1. You will need two H885-AA trilink connectors. Install an H879-AA terminator on one of the trilinks.

  2. Attach the trilink with the terminator to the controller that you want to be on the end of the shared SCSI bus. Attach an H885-AA trilink connector to the other controller.

  3. Install a BN21K or BN21L cable between the H885-AA trilink connectors on the two controllers. The BN21L-0B is a 15-centimeter (5.9-inch) cable.

  4. If you are using a DS-DWZZH-05:

  5. Install the UltraSCSI hub in:

  6. If you are using a:

  7. When the host bus adapters (KZPSA-BB or KZPBA-CB) have been installed in the member systems, for a:

Figure 10-18 shows a sample configuration with radial connection of KZPSA-BB PCI-to-SCSI adapters, DS-DWZZH-03 UltraSCSI hub, and an HSZ50 RAID array controller. Note that the KZPSA-BBs could be replaced with KZPBA-CB UltraSCSI adapters without any changes in cables.

Figure 10-18:  TruCluster Server Cluster Using DS-DWZZH-03, SCSI Adapter with Terminators Installed, and HSZ50

Table 10-7 lists the components that are used to create the cluster that is shown in Figure 10-18 and Figure 10-19.

Table 10-7:  Hardware Components Used in Configuration Shown in Figure 10-18 and Figure 10-19

Callout Number Description
1 BN38C cable [Footnote 77] [Footnote 78]
2 H885-AA HD68 trilink connector
3 H879-AA HD68 terminator
4 BN21K, BN21L, or 328215-00X cable [Footnote 78]

Figure 10-19 shows a sample configuration that uses KZPSA-BB SCSI adapters, a DS-DWZZH-05 UltraSCSI hub, and an HSZ50 RAID array controller.

Figure 10-19:  TruCluster Server Cluster Using KZPSA-BB SCSI Adapters, a DS-DWZZH-05 UltraSCSI Hub, and an HSZ50 RAID Array Controller

Note

The systems shown in Figure 10-19 use KZPSA-BB SCSI adapters. They could be KZPBA-CB UltraSCSI adapters without changing any cables in the configuration.

Table 10-7 lists the components that are used to create the cluster that is shown in Figure 10-18 and Figure 10-19.