Technical data

• 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 from 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 RA7000
or ESA 10000 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.
Hardware Requirements and Restrictions 2–13