HP StorageWorks XP Disk Array and Mainframe White Paper: Direct Attached Vs. Switched Vs. Cascaded FICON
Source: Hewlett-Packard (HP)
With the speed of FICON channels, and the availability of FICON ports on both the Mainframe and XP, one may think that simply direct attaching the XP to the Mainframe CHPIDs is the best thing to do. However, using a FICON Storage Network, with its switches and directors, provides several benefits when compared to a direct attached configuration. Switched FICON allows for better utilization of the host channels, more flexibility in the expansion of or replacement of control units, and the ability to consolidate ports on both the Mainframe and control unit. Further, Cascaded FICON allows one connect data centers together over fewer fibers or circuits, enabling a more cost effective disaster recovery or business continuity solution.