Deployment Guide

FIGURE 30 Zoning example
Approaches to zoning
Table 62 lists the various approaches you can take when implementing zoning in a fabric.
Approaches to fabric-based zoning TABLE 62
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.
Alternative approaches
Application Zoning by application typically requires zoning multiple, perhaps incompatible, operating systems
into the same zones. This method of zoning creates the possibility that a minor server in the
application suite could disrupt a major server (such as a Web server disrupting a data
warehouse server). Zoning by application can also result in a zone with a large number of
members, meaning that more notifications, such as registered state change notifications
(RSCNs), or errors, go out to a larger group than necessary.
Approaches to zoning
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