2    Hardware Requirements and Restrictions

This chapter describes the hardware requirements and restrictions for a TruCluster Server cluster. It includes lists of supported cables, trilink connectors, Y cables, and terminators.

The chapter discusses the following topics:

• Requirements for member systems in a TruCluster Server cluster (Section 2.1)

• Cluster interconnect requirements and restrictions (Section 2.2)

• Host bus adapter restrictions (including KGPSA, KZPSA-BB, and KZPBA) (Section 2.3)

• Disk device restrictions (Section 2.4)

• RAID array controller restrictions (Section 2.5)

• SCSI signal converters (Section 2.6)

• Supported DWZZH UltraSCSI hubs (Section 2.7)

• SCSI cables (Section 2.8)

• SCSI terminators and trilink connectors (Section 2.9)

For the latest information about supported hardware, see the following URLs:

• AlphaServer options for your system:

  
  http://www.compaq.com/alphaserver/products/options.html
   
  

• TruCluster Server technical updates:

  
  http://www.tru64unix.compaq.com/docs/pub_page/tcr_update.html
   
  

2.1    TruCluster Server Member System Requirements

The requirements for member systems in a TruCluster Server cluster are as follows:

• Each supported member system requires a minimum firmware revision. See the Cluster Release Notes supplied with the Alpha Systems Firmware Update CD-ROM.

  You can obtain firmware information from the Web at the following URL: http://thenew.hp.com

  Select Support, then select Compaq Driver Downloads, Software Updates and Patches. Then, in the Servers column, select AlphaServer. Select the appropriate system.

• Alpha System Reference Manual (SRM) console firmware Version 5.7 or later must be installed on any cluster member that boots from a disk behind an HSZ80, HSG60, or HSG80 controller. SRM console firmware Version 5.9-10 or 6.0 (depending upon your system) is required to support an HSV110. If the cluster member is using earlier firmware, the member may fail to boot, indicating "Reservation Conflict" errors.

• TruCluster Server Version 5.1B supports eight-member cluster configurations as follows:

  • Fibre Channel: Eight-member systems may be connected to common storage over Fibre Channel in a fabric (switch) configuration.

  • Parallel SCSI: Only four of the member systems may be connected to any one SCSI bus, but you can have multiple SCSI buses connected to different sets of nodes, and the sets of nodes may overlap. We recommend you use a DS-DWZZH-05 UltraSCSI hub with fair arbitration enabled when connecting four-member systems to a common SCSI bus using RAID array controllers.

    Illustrations of an externally terminated eight-node cluster are shown in Chapter 12. The cluster shown is more appropriate for high performance technical computing (HPTC) customers who are looking for performance instead of availability.

• The following items pertain to the AlphaServer GS80/160/320 systems:

  • High power peripheral component interconnect (PCI) modules (approximately 25 watts or greater) must be placed in PCI slots with a 1-inch module pitch; any slot except 0-5, 0-6, 1-5, and 1-6.

    A primary or expansion PCI drawer contains two 3-slot PCI buses and two 4-slot PCI buses (see Figure 2-1):

    • PCI0 for I/O riser 0: Slots 0-0/1, 0-2, and 0-3

    • PCI1 for I/O riser 0: Slots 0-4, 0-5, 0-6, and 0-7

    • PCI0 for I/O riser 1: Slots 1-1, 1-2, and 1-3

    • PCI1 for I/O riser 1: Slots 1-4, 1-5, 1-6, and 1-7

    Note

    Slot 0-0/1 in a primary PCI drawer contains the standard I/O module.

    Figure 2-1:  PCI Backplane Slot Layout

    

• TruCluster Server does not support the XMI CIXCD on an AlphaServer 8x00, GS60, GS60E, or GS140 system.

2.2    Cluster Interconnect Requirements and Restrictions

A cluster must have a dedicated cluster interconnect to which all cluster members are connected. This interconnect serves as a private communication channel between cluster members. The cluster interconnect can use either Memory Channel or a private local area network (LAN), but not both.

2.2.1    LAN Interconnect

Both 100 Mbps and 1000 Mbps LAN interconnects are suitable for clusters with low-demand workloads generated by a cluster running failover-style, highly available applications in which there is limited application data being shared between the nodes over the cluster interconnect.

No patches or additional code are required to use Gigabit Ethernet.

The AlphaServer DS20L only supports the LAN interconnect as the cluster interconnect.

2.2.2    Memory Channel Restrictions

The Memory Channel interconnect is one method used for cluster communications between the member systems.

There are currently three versions of the Memory Channel product: Memory Channel 1, Memory Channel 1.5, and Memory Channel 2. The Memory Channel 1 and Memory Channel 1.5 products are very similar (the PCI adapter for both versions is the CCMAA module) and are generally referred to as MC1 throughout this manual. The Memory Channel 2 product (CCMAB module) is referred to as MC2.

The Memory Channel restrictions are grouped into the following categories:

• Restrictions specific to one or multiple AlphaServer systems

• Restrictions pertaining to the hub mode or the number of Memory Channel rails

• Restrictions pertaining to the cables or optical converters.

Ensure that you abide by the following system-specific Memory Channel restrictions:

• The DS10, DS20, DS25, DS20E, ES40, ES45, GS80, GS160, and GS320 systems only support MC2 hardware.

• If redundant Memory Channel adapters are used with a DS10, they must be jumpered for 128 MB and not the default of 512 MB.

• The DS20L does not support a Memory Channel adapter. The cluster interconnect must be the LAN interconnect.

• The DS25 supports only one Memory Channel module. It must be installed in slot 5 and must be revision C1 or later.

• The DS25 does not support the Memory Channel fiber optics options.

• If redundant Memory Channel adapters are used with an ES45 Model 1, 1B, 2, or 2B, they must be jumpered for 128 MB because they are restricted to PCI bus 0, the only 5V 33-MHz PCI bus.

  The ES45 Model 3 and 3B has three 5V 33-MHz PCI buses, buses 0, 1, and 2. As long as redundant Memory Channel adapters are installed on different PCI buses, the Memory Channel adapters may be jumpered for 512 MB on an ES45 Model 3 or 3b.

• With an AlphaServer ES45, the Memory Channel API is not supported for data transfers larger than 8K bytes when loopback mode is enabled in two member clusters configured in virtual hub mode.

• If you have a Memory Channel module installed on a peripheral component interconnect (PCI) bus of a GS80, GS160, or GS320 system, that bus can contain only another MC2 module or the CCMFB fiber-optic module. No other module can be installed on that PCI bus, not even the standard I/O module.

• An MC2 module that is on the same PCI bus as a DEGPA or KGPSA in an AlphaServer 1200, AlphaServer 4000, or AlphaServer 4100 must be at revision D02 or later, or MC2 modules must not share a PCI bus with a DEGPA or KGPSA.

• For AlphaServer 8200, 8400, GS60, GS60E, or GS140 systems, the Memory Channel adapter must be installed in slots 0-7 of a DWLPA PCIA option; there are no restrictions for a DWLPB.

• For AlphaServer 1000A systems, the Memory Channel adapter must be installed on the primary PCI (in front of the PCI-to-PCI bridge chip) in PCI slots 11, 12, or 13 (the top three slots).

• For AlphaServer 2000 systems, the B2111-AA module must be at Revision H or higher.

  For AlphaServer 2100 systems, the B2110-AA module must be at Revision L or higher.

  Use the examine console command to determine whether these modules are at a supported revision as follows:

  P00>>> examine -b econfig:20008
  econfig: 20008 04
  P00>>>
  

  If a hexadecimal value of 04 or greater is returned, the I/O module supports Memory Channel.

  If a hexadecimal value of less than 04 is returned, the I/O module is not supported for Memory Channel usage.

  Order an H3095-AA module to upgrade an AlphaServer 2000 or order an H3096-AA module to upgrade an AlphaServer 2100 to support Memory Channel.

• For AlphaServer 2100A systems, the Memory Channel adapter must be installed in PCI 4 through PCI 7 (slots 6, 7, 8, and 9), which are the bottom four PCI slots.

Ensure that you abide by the following Memory Channel hub mode or number of rail restrictions:

• If you configure a cluster with a single rail Memory Channel in standard hub mode and the hub fails, or is powered off, every cluster member panics. They panic because no member can see any of the other cluster members over the Memory Channel interface. A quorum disk does not help in this case, because no system is given the opportunity to obtain ownership of the quorum disk and survive.

  To prevent this situation in standard hub mode (two member systems connected without a Memory Channel hub), install a second Memory Channel rail. A hub failure on one rail will cause failover to the other rail.

  When the Memory Channel is set up in standard hub mode (two or more systems connected to a hub), the Memory Channel hub must be visible to each member's Memory Channel adapter. If the hub is powered off, no system is able to boot.

  A two-node cluster configured in virtual hub mode does not have these problems. In virtual hub mode, each system is always connected to the virtual hub. A loss of communication over the Memory Channel causes both members (if both members are still up) to attempt to obtain ownership of the quorum disk. The member that succeeds continues as a single-member cluster. The other member panics.

  A single system of a two-node cluster that is configured in virtual hub mode will boot because a virtual hub is always present.

• If a TruCluster Server cluster configuration utilizes multiple Memory Channel adapters in standard hub mode, the Memory Channel adapters must be connected to separate Memory Channel hubs. The first Memory Channel adapter (mca0) in each system must be connected to one Memory Channel hub. The second Memory Channel adapter (mcb0) in each system must be connected to a second Memory Channel hub. Also, each Memory Channel adapter on one system must be connected to the same linecard in each Memory Channel hub.

• Redundant Memory Channels are supported within a mixed Memory Channel configuration, as long as MC1 adapters are connected to other MC1 adapters and MC2 adapters are connected to MC2 adapters.

  In a cluster with mixed revision Memory Channel rails, the MC2 adapter modules must be jumpered for 128 MB.

• A Memory Channel interconnect can use either virtual hub mode or standard hub mode. A TruCluster Server cluster with three or more member systems must be jumpered for standard hub mode and requires a Memory Channel hub.

• If Memory Channel modules are jumpered for virtual hub mode, all Memory Channel modules on a system must be jumpered in the same manner, either virtual hub 0 (VH0) or virtual hub 1 (VH1). You cannot have one Memory Channel module jumpered for VH0 and another jumpered for VH1 on the same system.

Ensure that you abide by the following cable or optical converter Memory Channel restrictions:

• The maximum length of an MC1 BC12N link cable is 3 meters (9.8 feet).

• The maximum length of an MC2 BN39B link cable is 10 meters (32.8 feet).

• In an MC2 configuration, you can use a CCMFB optical converter in conjunction with the MC2 CCMAB host bus adapter or a CCMLB hub line card to increase the distance between systems.

  • The BN34R fiber-optic cable, which is used to connect two CCMFB optical converters, is available in 10-meter (32.8-foot) (BN34R-10) and 31-meter (101.7-foot) (BN34R-31) lengths. Customers may provide their own fiber-optic cables to achieve greater separation of systems.

  • The Memory Channel fiber-optic connection may be up to 2 kilometers (1.24 miles) between two CCMFB optical converters connected to CCMAB host bus adapters in virtual hub mode.

  • The Memory Channel fiber-optic connection may be up to 3 kilometers (1.86 miles) between a CCMFB optical converter connected to a CCMAB host bus adapter and a CCMFB optical converter connected to a CCMLB hub line card in standard hub mode (providing a maximum separation of 6 kilometers (3.73 miles) between systems).

• Always examine a Memory Channel link cable for bent or broken pins. Be sure that you do not bend or break any pins when you connect or disconnect a cable.

2.3    Host Bus Adapter Restrictions

To connect a member system to a shared bus, you must install a host bus adapter in an I/O bus slot.

The Tru64 UNIX operating system supports a maximum of 64 I/O buses. TruCluster Server supports a total of 32 shared I/O buses using KZPSA-BB host bus adapters, KZPBA UltraSCSI host bus adapters, or KGPSA Fibre Channel host bus adapters.

The following sections describe the host bus adapter restrictions in more detail.

2.3.1    Fibre Channel Requirements and Restrictions

The following sections provide Fibre Channel requirements and restrictions.

2.3.1.1    General Fibre Channel Requirements and Restrictions

The following requirements and restrictions apply to the use of Fibre Channel with TruCluster Server Version 5.1B and general use:

• Table 2-1 lists the supported AlphaServer systems with Fibre Channel and the number of KGPSA-BC, DS-KGPSA-CA, and DS-KGPSA-DA Fibre Channel adapters that are supported on each system at the time the TruCluster Server Version 5.1B product was shipped. For the latest information about supported hardware, see the AlphaServer options list for your system at the following URL: http://www.compaq.com/alphaserver/products/options.html

  Table 2-1:  AlphaServer Systems Supported for Fibre Channel

  	Number of Adapters Supported in Fabric Topology
  AlphaServer System	KGPSA-BC	DS-KGPSA-CA	DS-KGPSA-DA [Footnote 1]	Number of Adapters Supported in Loop Topology
  AlphaServer 800	2	2	—	—
  AlphaServer 1200	4	4	—	—
  AlphaServer 4000, 4000A, or 4100	4	4	—	—
  AlphaServer DS10	2	2	2	2 [Footnote 2]
  AlphaServer DS10L	—	—	1	—
  AlphaServer DS20	4	4	—	2 [Footnote 2]
  AlphaServer DS20E	4	4	4	2 [Footnote 2]
  AlphaServer DS25	—	4	4	—
  AlphaServer ES40	4	4	6	2 [Footnote 2]
  AlphaServer ES45	—	4	6	—
  AlphaServer 8200 or 8400 [Footnote 3]	63 [Footnote 4] , 32 [Footnote 5]	63 [Footnote 4], 32 [Footnote 5]	—	—
  AlphaServer GS60, GS60E, and GS140 [Footnote 3]	63 [Footnote 4], 32 [Footnote 5]	63 [Footnote 4], 32 [Footnote 5]	—	—
  AlphaServer GS80	—	26 [Footnote 6] , 54 [Footnote 7]	54 [Footnote 7]	—
  AlphaServer GS160 and GS320	—	26 [Footnote 6], 62 [Footnote 8] , [Footnote 9]	62 [Footnote 8], [Footnote 9]	—

• Eight member systems may be connected to common storage over Fibre Channel in a fabric (switch) configuration. A maximum of two member systems is supported in arbitrated loop configurations.

• The only supported Fibre Channel adapters are the KGPSA-BC, DS-KGPSA-CA, and DS-KGPSA-DA. The KGPSA-BC and DS-KGPSA-DA adapters are supported in fabric configurations only; the DS-KGPSA-CA adapter is supported in either fabric or arbitrated loop configurations.

• The KGPSA-BC/CA PCI-to-Fibre Channel adapters are only supported on the DWLPB PCIA option; they are not supported on the DWLPA.

• The only supported Fibre Channel hub is the 7-port DS-SWXHB-07. The DS-SWXHB-07 has clock and data recovery on each port. It also features Gigabit Interface Converter (GBIC) transceiver-based port connections for maximum application flexibility. The hub is hot pluggable and is unmanaged.

• Only single-hub arbitrated loop configurations are supported; that is, there are no cascaded hubs on any SCSI bus.

• For a list of supported Fibre Channel switches, see the SAN Support Tables for the Heterogeneous Open SAN Design Reference Guide available at the following URL:

  
  http://www.compaq.com/products/storageworks/san/documentation.html
   
  

• Prior to 6 June 2002, some revision B, DS-DSGGB-AA SAN Switch 8 Fibre Channel switches were shipped with QuickLoop enabled. The switch serial numbers range from 3A24DRXZMxxx to 3A25DRXZLxxx, and were manufactured between 22 April and 21 May.

  To determine if the switch is not in QuickLoop mode, connect the serial line or telnet to the switch and enter the qlshow command. The proper response follows:

  :Admin> qlshow
  Switch is not in Quick Loop mode.
   
  

  If you do not get the proper response, enter the following commands:

  :Admin> qldisable
  cfgsave
   
  

  You do not need to reboot the Fibre Channel switch to effect this change.

• The Fibre Channel Tape Controller, Fibre Channel Tape Controller II, TL891, TL895, and ESL9326D are supported on a Fibre Channel storage bus. For more information, see the Enterprise Backup Solution with Legato NetWorker User Guide. Legato NetWorker Version 6.0 is required for application failover.

• Tapes are single-stream devices. There is no load balancing of I/O requests over the available paths to the tape devices. The first available path to the tape devices is selected for I/O.

2.3.1.2    Fibre Channel Requirements and Restriction Specific to the HSG60 and HSG80

The following requirements and restrictions apply to the use of Fibre Channel with TruCluster Server Version 5.1B and the HSG60 or HSG80:

• The HSG60 and HSG80 require Array Control Software (ACS) Version 8.5 or later.

• The Fibre Channel RAID Array 8000 (RA8000) midrange departmental storage subsystem and Fibre Channel Enterprise Storage Array 12000 (ESA12000) house two HSG80 dual-channel controllers. There are provisions for six UltraSCSI channels. A maximum of 72 disks is supported.

• The StorageWorks Modular Array 6000 (MA6000) supports dual-redundant HSG60 controllers and 1-inch universal drives.

• The StorageWorks Modular Array 8000 (MA8000) and Enterprise Modular Array 12000 (EMA12000) support dual redundant HSG80 controllers and 1-inch universal drives.

• The HSG60 or HSG80 Fibre Channel array controller support only disk devices.

• The HSG60 and HSG80 supports transparent and multiple-bus failover mode when used in a TruCluster Server Version 5.1B configuration. Multiple-bus failover is recommended.

• A storage array with dual-redundant HSG60 or HSG80 controllers in transparent mode failover is two targets and consumes four ports on a switch. Transparent mode is recommended only while upgrading from Tru64 UNIX Version 4.x. After the upgrade is complete, you should switch to multiple-bus failover.

• A storage array with dual-redundant HSG60 or HSG80 controllers in multiple-bus failover is four targets and consumes four ports on a switch.

• The HSG60 and HSG80 documentation refers to the controllers as Controllers A (top) and B (bottom). Each controller provides two ports (left and right). (The HSG60 and HSG80 documentation refers to these ports as Port 1 and 2, respectively.) In transparent failover mode, only one left port and one right port are active at any given time.

  With transparent failover enabled, assuming that the left port of the top controller and the right port of the bottom controller are active, if the top controller fails in such a way that it can no longer properly communicate with the switch, then its functions will fail over to the bottom controller (and vice versa).

• In transparent failover mode, you can configure which controller presents each HSG60 or HSG80 storage element (unit) to the cluster. Ordinarily, the connections on port 1 (left port) have a default unit offset of 0, and units designated D0 through D99 are accessed through port 1 of either controller. The connections on port 2 (right port) have a default unit offset of 100, and units designated D100 through D199 are accessed through port 2 of either controller.

• In multiple-bus failover mode, the connections on all ports have a default unit offset of 0, and all units (D0 through D199) are visible to all host ports, but accessible only through one controller at any specific time. The host can control the failover process by moving units from one controller to the other controller.

2.3.1.3    Fibre Channel Requirements and Restriction Specific to the Enterprise Virtual Array

The requirements and restrictions for use of the Enterprise Virtual Array in a TruCluster Server configuration are as follows:

• Only the KGPSA-BC, DS-KGPSA-CA, and DS-KGPSA-DA Fibre Channel adapters (FCA) are qualified for use with the Enterprise Virtual Array.

  Table 2-2 describes the AlphaServer systems and Fibre Channel adapters that are qualified for use with the Enterprise Virtual Array with the TruCluster Server software:

  Table 2-2:  AlphaServer Systems and Fibre Channel Adapters Supported with an Enterprise Virtual Array

  AlphaServer System	Fibre Channel Adapter Qualified
  DS10, DS20E, ES40	KGPSA-BC, DS-KGPSA-CA, and DS-KGPSA-DA
  ES45, GS80, GS160, GS320	DS-KGPSA-CA and DS-KGPSA-DA

• Fibre Channel switch zoning is required as follows:

  • Each SANworks Management Appliance (SWMA) with an HSV Element Manager must be in a zone with the HSV controllers it manages.

    The SWMA may be in a zone with a TruCluster Server cluster.

  • If there are multiple TruCluster Server clusters accessing the same Enterprise Virtual Array.

  • If there are any Windows NT or Windows 2000 systems accessing the same Enterprise Virtual Array as a TruCluster Server cluster.

• Use only one instance of the HSV Element Manager to configure and manage your HSV110 controller.

• A disk group requires at least 8 disks.

• The model of Fibre Channel adapter and switches configured with the Enterprise Virtual Array determine the type of fiber-optic cable you use.

  The HSV110 controllers, DS-KGPSA-DA Fibre Channel adapter, and McDATA ED-5000 switches accept the small form factor (SFF) Lucent Connector (LC) connector. The other Fibre Channel adapters and switches accept the subscriber connector (SC) connector.

  The fiber-optic cables required may be:

  • SC to SC

  • SC to LC

  • LC to LC

• A PC or Tru64 UNIX workstation on the network with the Enterprise Virtual Array with a supported browser is required to access the HSV Element Manager application on the SAN Appliance. The following browsers are supported:

  • Tru64 UNIX — Netscape Communicator

  • Windows NT Version 4.0 (SP 6a) — Netscape Communicator and Internet Explorer Version 5.01 or 5.5

  • Windows 2000 Version 5.0 (SP 2) — Netscape Communicator and Internet Explorer Version 5.01 or 5.5

    Note

    The Enterprise Virtual Array release notes specify that Netscape Version 4.77 is required for Tru64 UNIX, Windows NT, or Windows 2000. A later engineering advisory states that Netscape Version 4.78 is also supported. Netscape Version 4.76 is the default with Tru64 UNIX Version 5.1B, and has been used successfully. Netscape Version 4.75 has been used successfully with Windows 2000 Version 5.0 SP2.

• The Enterprise Virtual Array requires a multipathing environment. Each TruCluster Server AlphaServer system must have two KGPSA Fibre Channel adapters connected to separate Fibre Channel switches.

  One Fibre Channel switch is connected to Fibre Port 1 (FP1) on both HSV110 controllers. The other Fibre Channel switch is connected to Fibre Port 2 (FP2) on both HSV110 controllers.

• We recommend setting the OS unit ID for each virtual disk. Numbers between 1 and 32767 (inclusive) can be used. The IDs must be unique across the entire SAN, not just the HSV110 controllers. The OS unit ID is equivalent to the console user-defined identifier (UDID).

• You cannot connect a terminal or PC to an HSV110 controller to configure the controllers from a serial port as you did with an HSG80.

2.3.2    KZPSA-BB SCSI Adapter Restrictions

KZPSA-BB SCSI adapters have the following restrictions:

• The KZPSA-BB requires A12 firmware.

• If you have a KZPSA-BB adapter installed in an AlphaServer that supports the bus_probe_algorithm console variable (for example, the AlphaServer 800, 1000, 1000A, 2000, 2100, or 2100A systems), you must set the bus_probe_algorithm console variable to new by entering the following command:

  >>> set bus_probe_algorithm new
  

  Use the show bus_probe_algorithm console command to determine whether your system supports the variable. If the response is null or an error, there is no support for the variable. If the response is anything other than new, you must set it to new.

• On AlphaServer 1000A and 2100A systems, updating the firmware on the KZPSA-BB SCSI adapter is not supported when the adapter is behind the PCI-to-PCI bridge.

2.3.3    KZPBA-CB and 3X-KZPBA-CC SCSI Bus Adapter Restrictions

The 3X-KZPBA-CC SCSI bus adapter is a replacement for the KZPBA-CB. It is a rework of the KZPBA-CB to provide 3.3v signaling capability while retaining 5.0v signaling. A relayout of the board allowed activation of the 3.3v signaling capability. There were no other changes made to the adapter. The 3X-KZPBA-CC is fully 100 percent backward compatible with the KZPBA-CB. No firmware, software, or driver changes were necessary.

KZPBA UltraSCSI adapters have the following restrictions:

• SRM firmware Version 6.0 is required for 3X-KZPBA-CC support.

• The 3X-KZPBA-CC has been qualified on the following AlphaServer systems. The number of 3X-KZPBA-CC adapters supported on the system is shown in parenthesis.

  • DS10 (2)

  • DS10L (1)

  • DS20E (4)

  • DS25 (4)

  • ES40 (5)

  • ES45 (5)

  • GS80, GS160, and GS320 (62)

• The KZPBA requires ISP 1020/1040 firmware Version 5.57 or higher, which is available with the system SRM console firmware on the Alpha Systems Firmware 5.3 Update CD-ROM (or later).

• The KZPBA-CB and KZPBA-CC are collectively referred to as the KZPBA throughout the remainder of this manual.

• A maximum of four HSZ80 RAID array controllers can be placed on a single KZPBA UltraSCSI bus. Only two redundant pairs of array controllers are allowed on one SCSI bus.

• The maximum length of any differential SCSI bus segment is 25 meters (82 feet), including the length of the SCSI bus cables and SCSI bus internal to the SCSI adapter, hub, or storage device. A SCSI bus may have more than one SCSI bus segment. (See Section 3.1.)

2.4    Disk Device Restrictions

The restrictions for disk devices are as follows:

• Disks on shared buses must be installed in external storage shelves or behind a RAID array controller.

• TruCluster Server does not support Prestoserve on any shared disk.

2.5    RAID Array Controller Restrictions

RAID array controllers provide high performance, high availability, and high connectivity access to SCSI devices through a shared bus.

RAID array controllers require the minimum Array Controller Software (ACS) listed in Table 2-3.

Table 2-3:  RAID Controller Minimum Required Array Controller Software

RAID controllers can be configured with the number of SCSI IDs as listed in Table 2-4.

Table 2-4:  RAID Controller SCSI IDs

The following restrictions are imposed for support of the StorageWorks RAID Array 3000 (RA3000) subsystem:

• The RAID Array 3000 (RA3000) with HSZ22 controller does not support multi-bus access or multiple-bus failover. You cannot achieve a no-single-point-of-failure (NSPOF) cluster using an RA3000.

• The KZPBA UltraSCSI host adapter is the only SCSI bus host adapter supported with the RA3000 in a TruCluster Server cluster. The KZPBA requires ISP 1020/1040 firmware Version 5.57 (or higher), which is available with the system SRM console firmware on the Alpha Systems Firmware 5.4 or later Update CD-ROM.

• Only RA3000 storage units visible to the host as LUN0 (storage units with a zero (0) as the last digit of the unit number such as D0, D100, D200, and so forth) can be used as a boot device.

• StorageWorks Command Console (SWCC) V2.2 is the only configuration utility that will work with the RA3000. SWCC V2.2 runs only on a Microsoft Windows NT or Windows 2000 PC.

• The controller will not operate without at least one 16-MB SIMM installed in its cache.

• The device expansion shelf (DS-SWXRA-GN) for the rackmount version must be at revision level B01 or higher.

• The single-ended personality module used in the DS-SWXRA-GN UltraSCSI storage expansion shelves must be at revision H01 or higher.

• The RA3000 order includes an uninterruptible power supply (UPS), which must be connected to the RA3000.

2.6    SCSI Signal Converters

If you are using a standalone storage shelf with a single-ended SCSI interface in your cluster configuration, you must connect it to a SCSI signal converter. SCSI signal converters convert wide, differential SCSI to narrow or wide, single-ended SCSI and vice versa. Some signal converters are standalone desktop units and some are StorageWorks building blocks (SBBs) that you install in storage shelves disk slots.

Note

UltraSCSI hubs logically belong in this section because they contain a DOC (DWZZA on a chip) chip, but they are discussed separately in Section 2.7.

The restrictions for SCSI signal converters are as follows:

• If you remove the cover from a standalone unit, be sure to replace the star washers on all four screws that hold the cover in place when you reattach the cover. If the washers are not replaced, the SCSI signal converter may not function correctly because of noise.

• If you want to disconnect a SCSI signal converter from a shared SCSI bus, you must turn off the signal converter before disconnecting the cables. To reconnect the signal converter to the shared bus, connect the cables before turning on the signal converter. Use the power switch to turn off a standalone SCSI signal converter. To turn off an SBB SCSI signal converter, pull it from its disk slot.

• If you observe any "bus hung" messages, your DWZZA signal converters may have the incorrect hardware. In addition, some DWZZA signal converters that appear to have the correct hardware revision may cause problems if they also have serial numbers in the range CX444xxxxx through CX449xxxxx.

  To upgrade a DWZZA-AA or DWZZA-VA signal converter to the correct revision, use the appropriate field change order (FCO), as follows:

  • DWZZA-AA-F002

  • DWZZA-VA-F001

2.7    DS-DWZZH-03 and DS-DWZZH-05 UltraSCSI Hubs

The DS-DWZZH-03 and DS-DWZZH-05 series UltraSCSI hubs are the only hubs that are supported in a TruCluster Server configuration. They are SCSI-2- and draft SCSI-3-compliant SCSI 16-bit signal converters capable of data transfer rates of up to 40 MB/sec.

These hubs can be listed with the other SCSI bus signal converters, but because they are used differently in cluster configurations, they are discussed differently in this manual.

A DS-DWZZH-03 or DS-DWZZH-05 UltraSCSI hub can be installed in:

• A StorageWorks UltraSCSI BA356 shelf (which has the required 180-watt power supply).

• The lower righthand device slot of the BA370 shelf within the RA8000 or ESA12000 RAID array subsystems. This position minimizes cable lengths and interference with disks.

• A wide BA356 that has been upgraded to the 180-watt power supply with the DS-BA35X-HH option.

A DS-DWZZH-03 or DS-DWZZH-05 UltraSCSI hub:

• Improves the reliability of the detection of cable faults.

• Provides for bus isolation of cluster systems while allowing the remaining connections to continue to operate.

• Allows for more separation of systems and storage in a cluster configuration, because each SCSI bus segment can be up to 25 meters (82 feet) in length. This allows a total separation of nearly 50 meters (164 feet) between a system and the storage.

Note

The DS-DWZZH-03/05 UltraSCSI hubs cannot be connected to a StorageWorks BA35X storage shelf because the storage shelf does not provide termination power to the hub.

2.8    SCSI Cables

If you are using shared buses, you must determine if you need cables with connectors that are low-density 50-pins, high-density 50-pins, high-density 68-pins (HD68), or VHDCI (UltraSCSI). If you are using an UltraSCSI hub, you will need HD68-to-VHDCI and VHDCI-to-VHDCI cables. In some cases, you also have the choice of straight or right-angle connectors. In addition, each supported cable comes in various lengths. Use the shortest possible cables to adhere to the limits on SCSI bus length.

Table 2-5 describes each supported cable and the context in which you would use the cable. Some equivalent 6-3 part numbers are not provided.

Table 2-5:  Supported SCSI Cables

Always examine a SCSI cable for bent or broken pins. Be sure that you do not bend or break any pins when you connect or disconnect a cable.

2.9    SCSI Terminators and Trilink Connectors

Table 2-6 describes the supported trilink connectors and SCSI terminators and the context in which you use them.

Table 2-6:  Supported SCSI Terminators and Trilink Connectors

The requirements for trilink connectors are as follows:

• If you connect a SCSI cable to a trilink connector, do not block access to the screws that mount the trilink, or you will be unable to disconnect the trilink from the device without disconnecting the cable.

• Do not install an H885-AA trilink if installing it will block an adjacent peripheral component interconnect (PCI) port. Use a BN21W-0B Y cable instead.