HP StorageWorks Fabric OS 6.1.1 administrator guide (5697-0235, December 2009)

292 Optimizing fabric behavior

Figure 27 Traffic Isolation zone creating a dedicated path through the fabric

In Figure 27, all traffic entering Domain 1 from N_Port 8 is routed through E_Port 1. Similarly, traffic

entering Domain 3 from E_Port 9 is routed to E_Port 12, and traffic entering Domain 4 from E_Port 7 is

routed to the device through N_Port 6. Traffic coming from other ports in Domain 1 would not use E_Port 1,

but would use E_Port 2 instead.

Use the zone command to create and manage TI zones. See the Fabric OS Command Reference for

details about the zone command.

TI zone failover

Disable failover if you want to guarantee that TI zone traffic uses only the dedicated path, and that no

other traffic can use the dedicated path.

Enable failover if you want traffic to have alternate routes if either the dedicated or non-dedicated paths

cannot be used.

If failover is enabled, the following rules apply:

• If the dedicated path cannot be used, the TI zone traffic uses a non-dedicated path instead.

• Non-TI zone traffic uses the dedicated path if no other paths through the fabric exist, or if the

non-dedicated paths are not the shortest routes.

If failover is disabled, the following rules apply:

• If the dedicated path cannot be used, traffic for that TI zone is halted until the dedicated path is fixed.

• Non-TI zone traffic never uses the dedicated path, even if there are no other paths through the traffic.

IMPORTANT: If failover is disabled, use care when planning your TI zones so that non-TI zone devices are

not isolated. Make sure there are non-dedicated paths through the fabric for all devices that are not in a TI

zone.

For example, in Figure 27, if the dedicated ISL between Domain 1 and Domain 3 goes offline, the

following occurs, depending on the failover option:

• If failover is enabled for the TI zone, the traffic is routed from Domain 1 to Domain 3 through E_Ports

1,2 and 3,10.

• If failover is disabled for the TI zone, the traffic is halted until the ISL between Domain 1 and Domain 3

is back online.

If the non-dedicated ISL between Domain 1 and Domain 3 goes offline, the following occurs, depending

on the failover option:

• If failover is enabled for the TI zone, non-TI zone traffic is routed from Domain 1 to Domain 3 through

the dedicated ISL.

= Dedicated Path

Domain 1 Domain 3

Domain 4

= Ports in the TI zone