IBM AIX HACMP SG24-5131-00, Hardware User Manual

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Cluster Hardware and Software Preparation
77
Figure 11. 7135-110 RAIDiant Arrays Connected on Two Shared 16-Bit SCSI Buses
3.3.2.3 Adapter SCSI ID and Termination change
The SCSI-2 Differential Controller is used to connect to 8-bit disk devices on
a shared bus. The SCSI-2 Differential Fast/Wide Adapter/A or Enhanced
SCSI-2 Differential Fast/Wide Adapter/A is usually used to connect to 16-bit
devices but can also be used with 8-bit devices.
In a dual head-of-chain configuration of shared disks, there should be no
termination anywhere on the bus except at the extremities. Therefore, you
should remove the termination resistor blocks from the SCSI-2 Differential
Controller and the SCSI-2 Differential Fast/Wide Adapter/A or Enhanced
SCSI-2 Differential Fast/Wide Adapter/A. The positions of these blocks (U8
and U26 on the SCSI-2 Differential Controller, and RN1, RN2 and RN3 on the
T
Controller 1
Controller 2
Controller 1
Controller 2
#2902
T
T
T
#2902
#2902
#2902
#2416 (16-bit)
#2416 (16-bit)
#2426
7135-110
7135-110
#2416 (16-bit)
#2416 (16-bit)
#2424
#2416 (16-bit)
#2416 (16-bit )
#2426
#2416 (16-bit)
#2416 (16-bit)
#2426
Maximum total cable length: 25m
#2902
RAID
cable
#2902
RAID
cable
#2426