Compaq AA-RHGWC-TE manual DS-DWZZH-03 and DS-DWZZH-05 UltraSCSI Hubs

______________________ Note _______________________

We could list the UltraSCSI hubs 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 of CX444xxxxx to 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

2.7DS-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).

Hardware Requirements and Restrictions 2–11