Compaq TruCluster Server AA-RHGWB-TE, Руководство пользователя

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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