Chapter 3. Planning 57
Figure 3-5   Overview of eight-path host zoning
For more information, see Chapter 8, “Hosts” on page 317.
3.6.6  Zoning considerations for Metro Mirror and Global Mirror
The SAN configurations that use intercluster Metro Mirror and Global Mirror relationships 
require the following other switch zoning considerations: 
/SM590000Review the latest requirements and recommendations at this website.
/SM590000If two ISLs are connecting the sites, split the ports from each node between the ISLs. That 
is, exactly one port from each node must be zoned across each ISL.
/SM590000Local clustered system zoning continues to follow the standard requirement for all ports on 
all nodes in a clustered system to be zoned to one another.
When designing zoning for a geographically dispersed solution, consider the effect of the 
cross-site links on the performance of the local system.
The use of mixed port speeds for intercluster communication can lead to port congestion, 
which can negatively affect the performance and resiliency of the SAN. Therefore, it is not 
supported.
Important: Be careful when you perform the zoning so that ports that are dedicated for 
intra-cluster communication are not used for Host/Storage traffic in the 8-port and 12-port 
configurations.