Redundant Controller
10-3
The physical connection between redundant controllers should be similar
to the one shown above. The basic configuration rules are:
1. All channels should be connected to both controllers as diagrammed
above or strung across via a common backplane. Disk drives are
connected to both controllers.
2. Cached writes are constantly duplicated in both controllers’ memory
over a dedicated SCSI channel. The default path for controller
communications (SCSI-based controllers) is channel 0.
Channel 0 is also the default for host interface; therefore, avail other
channel(s) for host connection by changing its channel mode. See
Chapter 7 for details about channel mode configuration.
3. SCSI channels should be terminated on both ends. It is
recommended to use the termination jumpers on the SCSI-based
controllers to configure the termination setting. Terminators are
provided on controller back-end PCBs. This design allows the
controller to be removed during the controller failover process.
Fibre-Based Controllers
Connection between controllers is more flexible with the Fibre-based
controllers.
Figure 10 - 2 Dual-Controller Configuration Using Fibre-
Based Controllers
