HP AA979A - StorageWorks SAN Switch 2/8V Administrator's Manual page 366

Table 88 Considerations for Zoning architecture
Item
Type of Zoning: hard or
soft (session-based)
Use of aliases
Security requirements
Interoperability Fabric
QLFA zones
Testing
Effect of changes in a
production fabric
Confirming operation
366 Administering Advanced Zoning
Description
If security is a priority, hard Zoning is recommended.
The use of aliases is optional with Zoning. Using aliases
requires structure when defining zones. Aliases will aid
administrators of zoned fabric in understanding the structure
and context.
Evaluate the security requirements of the fabric. If additional
security is required, add Secure Fabric OS into the fabric.
If the fabric includes a third-party switch product, only WWN
Zoning is supported. Other types of Zoning, including
QuickLoop, are not supported.
Evaluate if the fabric will have QuickLoop Fabric Assist (QLFA)
or QuickLoop (QL) in it, and consider the following items
before creating and setting up QLFA zones:
QuickLoop Zoning—QuickLoop/QuickLoop zones cannot run
on Fabric OS v4.1.0 or later. However, Fabric OS can manage
(create, remove, update) QL zones.
QuickLoop Fabric Assist—A switch running Fabric OS v4.1.0
or later cannot have a Fabric Assist host directly connected to
it. However, such a switch can be part of a Fabric Assist zone
if a Fabric Assist host is connected to a compatible switch in
the fabric.
Testing a (new) zone configuration. Before implementing a
zone, the user should run the Zone Analyzer from Web Tools
to isolate any possible problems. This is especially useful as
fabrics increase in size.
Zone changes in a production fabric can result in a disruption
of I/O under conditions where an RSCN is issued as a result
of a zone change and the HBA is unable to process the RSCN
fast enough. Though RSCNs are a normal part of a
functioning SAN, the pause in I/O might not be acceptable.
For these reasons, it is recommended to perform zone changes
only when the resulting behavior is predictable and
acceptable. Changing HBA drivers can rectify the situation.
After changing or enabling a zone configuration, the user
should confirm that the nodes and storage are able to identify
and access one another. Depending on the platform, the user
might need to reboot one or more nodes in the fabric with the
new changes.