Compaq AA-RHGWB-TE manual Using a Dwzzh UltraSCSI Hub in a Cluster Configuration

3.6.1 Using a DWZZH UltraSCSI Hub in a Cluster Configuration

The DS-DWZZH-03 and DS-DWZZH-05 UltraSCSI hubs are supported in a TruCluster Server cluster. They both provide radial connection of cluster member systems and storage, and are similar in the following ways:

•Contain internal termination for each port; therefore, the hub end of each SCSI bus segment is terminated.

_____________________ Note _____________________

Do not put trilinks on a DWZZH UltraSCSI hub as it is not possible to remove the DWZZH internal termination.

•Require that termination power (termpwr) be provided by the SCSI bus host adapters on each SCSI bus segment.

_____________________ Note _____________________

The UltraSCSI hubs are designed to sense loss of termination power (such as a cable pull or termpwr not enabled on the host adapter) and shut down the applicable port to prevent corrupted signals on the remaining SCSI bus segments.

3.6.1.1 DS-DWZZH-03 Description

The DS-DWZZH-03:

•Is a 3.5-inch StorageWorks building block (SBB)

•Can be installed in:

–A StorageWorks UltraSCSI BA356 storage 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 non-UltraSCSI BA356 which has been upgraded to the 180-watt power supply with the DS-BA35X-HH option.

•Has three Very High Density Cable Interconnect (VHDCI) differential SCSI bus connectors

•Does not use a SCSI ID

•Uses the storage shelf only to provide its power and mechanical support (it is not connected to the shelf internal SCSI bus).

Shared SCSI Bus Requirements and Configurations Using UltraSCSI Hardware 3–9