196Software Installation and User’s GuideOptional FeaturesA.1.1 ICP RAID Controllers in a Cluster ConfigurationDue to required cable lengths (several meters) for the shared I/O channel(s) and thedemands on transfer performance and quality, only Ultra160/320 SCSI and Fibre Channelcontrollers are suitable for clustering. Using such controllers allows for sufficientdistances between the two servers and the RAID enclosure.For the successful installation and setup of clustering systems, note that computersystems, RAID Controllers, mass storage enclosures and accessories of suitable quality,such as cables, terminators, SCSI Bus Repeaters, and Isolators or Converters are allimportant.A.1.2 Hardware InstallationSCSI channels which are used as a shared I/O bus require 2 SCSI Bus separators pershared channel to ensure that the shared channel will work even if a server is switched off,or if the bus is separated from the ICP RAID controller in one of the servers.A.1.3 Using ICP RAID Controllers with SCSI InterfacesBoth ICP RAID controllers for the two nodes should be identical (same model, samefirmware level).Before connecting both controllers to the shared I/O cable, one of the IOPs (In-put/OutputProcessor) on one of the controllers must be set to another SCSI ID for example, ID6. Thisshould be done for all I/O channels which are used as Clustering channels. The easiestway to change the IOP IDs is to use ICPCON (ICP RAID Console) loaded with+ from the controller's ROM.
