Sun Microsystems Sun StorEdge T3 - Manual (Page 58)

46 Sun StorEdge T3 and T3+ Array Configuration Guide • August 2001
Switch Host Connection
This section contains the following example configurations:
■ “Dual Hosts With Two Switches and Two Controller Units” on page 46
■ “Dual Hosts With Two Switches and Eight Controller Units” on page 48
Dual Hosts With Two Switches and Two
Controller Units
FIGURE 4-12 shows two application hosts connected through FC-AL cables to two
switches and two 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.
Evaluate the following limitations before 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 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.