54 Implementing the IBM Storwize V7000 with IBM Spectrum Virtualize V8.2.1
3.6.5  Host zones
Host must be zoned to the I/O Group to access volumes that are presented by this I/O Group. 
The preferred zoning policy is to create a separate zone for each host HBA port, and place 
exactly one port from each node in each I/O group that the host accesses in this zone. For 
deployments with more than 64 hosts defined in the system, this host zoning scheme is 
mandatory.
If you plan to use NPIV, see the other host zoning requirements at that available at this 
website.
When a dual-core SAN design is used, it is a requirement that no internode communications 
use the ISL link. When you create host zones in this type of configuration, ensure that each 
system port in the host zone is attached to the same Fibre Channel switch.
Consider the following rules for zoning hosts with the Storwize V7000:
/SM590000HBA to Storwize V7000 port zones
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. 
It is not prohibited to zone host’s HBA to one port from every node in the cluster, but it 
does reduce the maximum number of hosts that can be attached to the system.
/SM590000Maximum host paths per logical unit (LU)
For any volume, the number of paths through the SAN from the Storwize V7000 nodes to 
a host must not exceed eight. For most configurations, four paths to an I/O Group are 
sufficient.
Another way to control the number of paths between hosts and the Storwize V7000 is to 
use port mask. The port mask is an optional parameter of the mkhost and chhost 
commands. The port-mask configuration has no effect on iSCSI connections.
For each login between a host Fibre Channel port and node Fibre Channel port, the node 
examines the port mask for the associated host object. It then determines whether access 
is allowed (port mask bit for specific port is set) or denied (port mask bit is cleared). 
If access is denied, the node responds to SCSI commands as though the HBA WWPN is 
unknown. The port mask is 64 bits. Valid mask values range from all zeroes (no ports 
enabled) to all ones (all ports enabled). For example, a mask of 0011 enables port 1 and 
port 2. The default value is all 1s.
Number of paths: For n + 1 redundancy, use the following number of paths:
/SM590000With two HBA ports, zone HBA ports to Storwize V7000 ports 1:2 for a total of four 
paths.
/SM590000With four HBA ports, zone HBA ports to Storwize V7000 ports 1:1 for a total of four 
paths.
/SM590000Optional (n+2 redundancy): With four HBA ports, zone HBA ports to Storwize V7000 
ports 1:2 for a total of eight paths.
Here, the term HBA port is used to describe the SCSI initiator and Storwize V7000 port 
to describe the SCSI target. 
Important: The maximum number of host paths per LUN must not exceed eight.