Data Replication Manager Windows-Based Server with Single Host Bus Adapter - Application Notes

Additional Considerations
14 Application Notes – Data Replication Manager Windows-Based Server with Single Host Bus Adapter
In larger configurations, the combination of the use of single FC HBA server clusters and multiple FC
switches and the spreading of host port 1 of the HSG80 controllers over more than one FC switch
results in a solution that has no SPOF. This configuration is shown in Figure 9. In this case, a failure of
the right FC switch causes the replication process to cease, but operation continues.
The FC switches also report any loss of signal, which can be caused by the loss of a FC HBA, fiber
optic cable, or the other FC switch. If you wish to add a second ISL, it should be added to the left FC
switch.
Figure 9: Cluster of single-FC HBA servers with multiple switches
Zoning Within the FC Fabric
Zoning is a function within the FC switch that allows the creation of multiple virtual SANs in one
physical SAN. The reasons to implement zoning in a configuration can be either technical or business.
An example of a technical reason would be that Compaq Tru64 UNIX clusters may not be detected by
any other node on the SAN. A classic example of a business reason is a desire to separate the
development department systems from the human relations department systems, while allowing both
groups to share the same storage infrastructure.
There are no special technical reasons to use zoning in configurations consisting solely of single
FC HBA servers. However, all other technical reasons to implement zoning still apply. Please refer to
Compaq StorageWorks Heterogeneous Open SAN Design Reference Guide for more details.
Zoning is not mandatory with single FC HBA servers. However, if a dual FC HBA server is added to
the configuration, zoning must be implemented.
NOTE: Because interswitch or intersite links are part of the FC fabric and are not seen by the FC
switches as end nodes, they are never part of any zone. The zoning rules in the Compaq
StorageWorks Heterogeneous Open SAN Design Reference Guide still apply.