Compaq AA-RHGWB-TE manual DS-DWZZH-03 and DS-DWZZH-05 UltraSCSI Hubs, Scsi Cables

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

The DS-DWZZH-03 and DS-DWZZH-05 series UltraSCSI hubs are the only hubs 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 as they are used differently in cluster configurations they will be 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 RA7000 or ESA 10000 RAID array subsystems. This position minimizes cable lengths and interference with disks.

•A wide BA356 which 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 in length. This allows a total separation of nearly 50 meters 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.

2.9 SCSI Cables

If you are using shared SCSI 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.

Hardware Requirements and Restrictions 2–9