Metrocluster Zoning And Ti Zones - IBM N series Hardware Manual

8.6 MetroCluster zoning and TI zones

Traditional SAN has great flexibility in connecting devices to ports if the ports are configured
correctly and any zoning requirements are met. However, a MetroCluster expects certain
devices to be connected to specific ports or ranges of ports. Therefore, it is critical that
cabling is exactly as described in the installation procedures. Also, no switch-specific
functions, such as trunking or zoning, are used in a Fabric MetroCluster, which makes switch
management minimal.
The TI zone feature of Brocade/IBM B type switches (FOS 6.0.0b or later) allows you to
control the flow of interswitch traffic. You do so by creating a dedicated path for traffic that
flows from a specific set of source ports. In a fabric MetroCluster configuration, the traffic
isolation feature can be used to dedicate an ISL to high-priority cluster interconnect traffic.
FCVI exchanges must be isolated because they are high priority traffic that should not be
subject to any interruption or congestion caused by storage traffic.
Fabric OS v6.0.0b introduces Traffic Isolation Zones, which have the following features:
Can create a dedicated route
Does not modify the routing table
Is implemented across the entire data path from a single location
Does not require a license
TI Zones are called zones, but they are really about FSPF routing
TI Zones need a standard zoning configuration in effect
TI Zones display only in the defined zoning configuration (not in effective zoning
configuration)
Create TI Zones by using Domain, Index (D, I) notation
E_Ports and F_ and FL_Ports must be included for an end-to-end route (initiator - target)
Ports are only members of a single TI Zone
Without TI Zones, traffic can use either ISL, which is subject to the rules of FSPF (Fibre
Channel shortest path first) and DPS (Dynamic Path Selection), as shown in Figure 8-11.
Figure 8-11 Traffic flow without TI Zones
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IBM System Storage N series Hardware Guide