Sun Microsystems T3 manual Dual Hosts With Two Switches and Eight Controller Units

Dual Hosts With Two Switches and Eight Controller Units

FIGURE 4-13shows two application hosts connected through FC-AL cables to two switches and eight Sun StorEdge T3+ arrays. This multi-initiator configuration, can be used for footprint and I/O throughput.

Note – This configuration is not a recommended for RAS functionality because the controller is a single point of failure.

The following limitations should be evaluated when proceeding with this configuration:

■Avoid the risk caused by any array or data path single point of failure using host- based mirroring software such as VERITAS Volume Manager or Solaris Logical Volume Manager.

■When configuring more than a single array to share a single FC-AL loop, as with a hub, array target addresses need to be set to unique values.

Each array needs to be assigned a unique target address using the port set command. These target addresses can be any number between 1 and 125. At the factory, the array target addresses are set starting with target address 1 for the bottom array and continuing to the top array. Use the port list command to verify that all arrays have a unique target address. Refer to Appendix A of the Sun StorEdge T3 and T3+ Array Administrator’s Guide for further details.

The following two parameters must be set on the master controller unit, as follows:

■cache mode = auto

■cache mirroring = auto

Note – For information on setting these parameters, refer to the Sun StorEdge T3 and T3+ Array Administrator’s Guide.

48 Sun StorEdge T3 and T3+ Array Configuration Guide • August 2001