Channel-redundant configuration
The minimum configuration does not provide for alternative paths. The availability of a CTC communication, in the event of a single channel or FICON® Director port failure, can be increased by defining a second shared FC channel for each processor or a second unshared FC channel for each partition. The number of shared FC channels required to allow any partition to communicate with any other partition is:
FC channels = 2xM
where M = number of processor complexes
For unspanned FC channels that are shared on a processor complex that supports multiple logical channel subsystems, the value M above is equal to the total number of logical channel subsystems on the processor complexes.
The number of unshared FC channels required to allow any partition to communicate with any other partition is:
FC channels = 2xn
where n = number of processor complexes in basic mode
or number of logical partitions in LPAR mode