HP StorageWorks XP Disk Array Mainframe Host Attachment and Operations Guide XP24000, XP20000 (A5951 - 96151, September 2007)

Figure 4 Mainframe Logical Paths (Example 2)
The FICON channel adapters provide logical path bindings that map user-defined FICON logical
paths. Specifically:
• Each CU port can access 255 CU images (all CU images of logical storage system).
• To the CU port, each logical host path (LPn) connected to the CU port is defined as a channel
image number and a channel port address. The LPn identifies the logical host path by the channel
image number and channel port address (excluding CU image number).
In the following figure, Host Path(1) and Host Path(2) have the same channel image number and CU
image number. However, they correspond to different paths because the channel address (and LPn)
is different.
Figure 5 FICON Channel Adapter Support for Logical Paths (Example 1)
The following figure shows another example of logical paths. Instead of being controlled by physical
ports, LPns on the storage system are controlled by CU images. Separating LPns from hardware
provides flexibility that allows CU ports to share logical path resources as needed.
Specifically:
• The maximum number of LPn/CU images per storage system is 2048.
• The maximum number of CU images per storage system is 64.
XP Disk Array Mainframe Host Attachment and Operations Guide 29