HP Brocade 4Gb SAN Switch for HP BladeSystem p-Class - Manual (Page 124)

124 Administering advanced zoning
Zoning concepts
Before using the procedures, you should become familiar with the zoning concepts described in the
following sections.
Zone types
Table 18 summarizes the types of zoning and Table 19 summarizes the primary forms.
Table 18 Types of zoning
Zone type Description
Storage-based Storage units typically implement LUN-based zoning, also called LUN masking.
LUN-based zoning limits access to the LUNs on the storage port to the specific
WWN of the server HBA. It is needed in most SANs. It functions during the probe
portion of the SCSI initialization. The server probes the storage port for a list of
available LUNs and their properties. The storage system compares the WWN of
the requesting HBA to the defined zone list, and returns the LUNs assigned to the
WWN. Other LUNs on the storage port are not made available to the server.
Host-based Host-based zoning can implement WWN or LUN masking.
Fabric-based Fabric switches implement fabric-based zoning, in which the zone members are
identified by WWN or port location in the fabric. Fabric-based zoning is also
called name server-based or soft zoning.
HP StorageWorks switches might also provide additional hardware enforcement
of the zone. When a device queries the fabric Name Server, the Name Server
determines the zones in which the device belongs. The server returns information
on all members of the zones in the fabric to the device. Devices in the zone are
identified by node WWN, port WWN, or domain, port of the switch to which the
device is connected.
Fabric-based zoning is perhaps the most controversial aspect of zoning. There are
several approaches for implementing fabric-based zoning; all of them work, in
most cases. However, there are pros and cons to each form.