HP Mainframe Connectivity Design Guide

• Number of paths between a mainframe and a storage system
• Distance (in circuit miles/km) between a mainframe and a storage system
Levels
The data availability levels are as follows:
• Level 1: single connectivity fabric
• Level 2: single resilient fabric
• Level 3: single resilient fabric with multiple device paths
• Level 4: multiple fabrics and device paths (NSPOF)
Level 1: single connectivity fabric
Level 1 provides maximum connectivity, but does not provide fabric resiliency or redundancy. Each
mainframe and storage system has one path to the director. Figure 4 (page 20) shows a level 1
fabric.
Figure 4 Level 1: single connectivity fabric
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20 FICON SAN fabric topologies