EMC Connectrix EC-1100 System User Manual page 95

Using Port Numbers
Move the cursor over the Configure icon, then click Nickname on the
pop-up menu to find the WWN of the fabric and assign it a nickname.
There are two important advantages to identifying a zone member as
the WWN of the attached device:
• The zone member identification will not change if the fiber cable
connections to ports are rearranged. ED-1032 port card field
repair procedures require moving the connections from the port
card being replaced to the spare ports. Device drivers are being
engineered and tested to automatically pass through this
procedure depending on WWN-based zoning.
• Strategies for correcting ISL congestion in fabrics includes
moving high-traffic port pairs into a common domain. When
WWN-based zoning is used, these connections can be moved to a
common domain without effecting device driver configurations,
ED-1032 zoning configurations, or Symmetrix configurations.
EMC strongly discourages zoning by port numbers, for the following
reasons:
• The repair of a port card and the use of spare ports will require
changes to the zone set. This is not a part of the field procedure
for port card repair.
• If the domain ID changes (which can happen if a set of single
ED-1032s are reconfigured into a fabric), the zoning information
will be invalid, which can lead to data corruption.
• Managing ISL congestion by relocating high-traffic port pairs to a
common domain will not be handled automatically, and the
movement of these links without adjusting the port's zoned
information can lead to data corruption.
Zoning by port numbers is sometimes considered as a way of
managing the replacement of host bus adapters (HBAs). When zoned
by port numbers, HBAs can be replaced without modifing the
zoning information. This is an incomplete solution, because changing
an HBA requires changing the Volume Logix database. A new feature
in Connectrix Manager is a Replace WWN function that can be used
to replace a bad HBA's WWN with the WWN of the new HBA. Refer
to Find Zones; Find and Replace WWNs on page 4-23.
Fabric Zoning
Zoning Concepts
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