Rules For Expanding An Ultrascsi Bus - Compaq StorageWorks DS-BA370 Series User Manual

Rules for Expanding an UltraSCSI Bus

See Table 5–1 for possible causes of TERMPOWER problems.
Table 5–1 TERMPOWER Problems
TERMPOWER Error
Internal
External
Removing an I/O module disconnects the SCSI bus termination,
resulting in a loss of TERMPOWER available to the internal SCSI
bus. Without TERMPOWER, the bus cannot function correctly.
By connecting the master enclosure to one or two expansion
enclosures, each SCSI bus is expanded from a 4-device bus to an 8- or
12-device bus, respectively. See Chapter 4 for a discussion of valid
enclosure SCSI bus addresses and the associated array controller and
storage device SCSI bus IDs.
Wide UltraSCSI supports a maximum of 16 devices per bus
(2 array controllers and 14 disk drives). However, Compaq
does not support any configuration with more than 12 disk
drives.
To expand a SCSI bus, use the 68-pin VHDCI receptacle connectors
on the I/O module and a BN37A series cable. See Table 5–2 for a list
of the rules for expanding an UltraSCSI bus.
Single-Ended I/O Module
Possible Causes
I/O module
Power supply
I/O module
Power supply
External SCSI bus cable
Note
UltraSCSI RAID Enclosure 5–7