HP StorageWorks Fabric OS 6.x administrator guide (5697-7344, March 2008)

388 Administering Advanced Zoning
Zone types
Table 84 summarizes the types of zoning available.
NOTE: Fabric OS has several types of zones that do not behave like the “regular” zones described here.
These special zones include broadcast zones, Traffic Isolation zones, and QoS zones. See ”Broadcast
zones” on page 395, ”Traffic isolation” on page 333, and ”QoS: SID/DID traffic prioritization” on
page 340 for information about these special zones.
Table 85 lists the various approaches you can take when implementing zoning in a fabric.
Table 84 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 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.
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.
The primary approaches to fabric-based zoning are summarized in Table 85.
Table 85 Approaches to fabric-based zoning
Zoning
approach
Description
Recommended approach
Single HBA Zoning by single HBA most closely re-creates the original SCSI bus. Each
zone created has only one HBA (initiator) in the zone; each of the target
devices is added to the zone. Typically, a zone is created for the HBA and
the disk storage ports are added. If the HBA also accesses tape devices, a
second zone is created with the HBA and associated tape devices in it. In
the case of clustered systems, it could be appropriate to have an HBA from
each of the cluster members included in the zone; this is equivalent to having
a shared SCSI bus between the cluster members and assumes that the
clustering software can manage access to the shared devices.
In a large fabric, zoning by single HBA requires the creation of possibly
hundreds of zones; however, each zone contains only a few members. Zone
changes affect the smallest possible number of devices, minimizing the
impact of an incorrect zone change. This zoning philosophy is the preferred
method.