Figure 3-11 shows a host zoning example. It is not prohibited to zone host’s HBA to one port from ev ery node in the cluster, but it will  reduce the maximum number of hosts that can be attached to the system. Optional ( n +2 redundancy): With four HBA ports, zone HBA ports to SAN Volume  Controller ports 1:2 for a total of eight paths. Here, the term  HBA port  is used to describe the SCSI initiator and  SAN Volume  Controller port  is used to describe the SCSI target.  Important:  The maximum number of host paths per LUN must not exceed eight. Chapter 3. Planning  61 Consider the following rules for zoning hosts with the SAN Volume Controller: AC DC AC DC SVC-Power System Zone P1: Fabric Domain ID, Port  21,1 - 11,0 - 11,1  SVC-Power System Zone P2: Fabric Domain ID, Port  22,1 - 12,2 - 12,3  Fabric ID 12  Fabric ID 11  Fabric ID 22  Fabric ID 21  Zoning Info:  One  Power System  Port and  one  SVC  Port  per  SVC Node Fabric  1  Fabric  2  Ports 0 1 2 3 8 9  Ports 0 1 2 3 8 9  Ports 0 1 2 3 8 9  Ports 0 1 2 3 8 9  IBM Power System  P1  P2  ISL ISL Figure 3-11 Host zoning example GLYPH<SM590000> HBA to SAN Volume Controller port zones GLYPH<SM590000> Maximum host paths per logical unit (LU) GLYPH<SM590000> With two HBA ports, zone HBA ports to SAN Volume Controller ports 1:2 for a total  of four paths. GLYPH<SM590000> With four HBA ports, zone HBA ports to SAN Volume Controller ports 1:1 for a total  of four paths. Place each host’s HBA in a separate zone with exactly one port from each node in each  I/O group that the host accesses.  For any volume, the number of paths through the SAN from the SAN Volume Controller  nodes to a host must not exceed eight. For most configurations, four paths to an I/O Group  are sufficient. Number of paths:  For  n  + 1 redundancy, use the following number of paths: