Why manage logical paths?

The FICON® environments (the use of FICON Express channels and FICON Directors) greatly enhances the connectivity potential for control units. In addition, you can define shared channels that can request additional logical paths. However, control units can only allocate a limited number of logical paths in relation to the number of logical paths that channels can request. In configurations where channels request more logical paths than a control unit can allocate, you must manage logical paths to help ensure that the I/O operations you intend take place.

The FICON Express offers increased connectivity in the same amount of physical space, and offer the possibility of increased performance. Up to 384 FICON Express16SA, Express32S channels and Express32G channels on a z17 model and can be employed to greatly expand connectivity and throughput capability. The FICON connectivity solution is based on industry-standard Fibre Channel technology and uses our exclusive native FICON architecture. For detailed information, see Input/Output Configuration Program User's Guide for ICP, SB10-7183.