ICP GDT6618RD, Addendum

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B. Installation Notes
B.1 Hardware Installation
Wide/Ultra2 SCSI or Ultra 160 SCSI channels which are used as a shared I/O bus require per
shared channel 2 SCSI Wonders to make sure that the shared channel continues to work
even if a server is switched off, or if the bus is separated from the ICP Controller in one of
the servers.
For the configuration of Cluster Systems with ICP Fibre Channel Controllers, it is recom-
mended to use the ICP Fibre Hub 1016, which ensures that the loop is always closed even if
one Controller fails, or if the fibre channel cable is removed. ICP Controllers with two inde-
pendent loops allow the set up of a dual loop configuration. In such a configuration, there
is not only redundancy at server level but also at I/O channel level: One loop can fail and
the system continues to run on the other loop. ICP Fibre Hub 1016 was specifically de-
signed for such dual loop configurations (it consists of two independent Hub Modules and
two independent power supplies).
B.2 Using Wide/Ultra2 and Ultra 160 SCSI ICP Controllers
Both ICP Controllers for the two nodes should be identical (same model, same firmware
level).
Before connecting both controllers to the shared I/O cable, one of the IOPs (Input/Output
Processor) on one of the controllers must be set to another ID e.g., ID6). This has to be
done for all I/O channels which are used as Clustering channels. The easiest way to change
the IOP IDs is to use ICPCON (ICP RAID Console) loaded with <CTRL>+<G> from the con-
troller's ROM.