Cisco Nexus 5000 Series Switch CLI Software Configuration Guide, NX-OS 4.0(1a)N1 (OL-16597-01, January 2009)

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34-4
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
OL-16597-01
Chapter 34 Configuring N Port Virtualization
Information About NPV
• The same device might log in using different fWWNs on the core switch (depending on the NPV
link it uses) and may need to be zoned using different fWWNs.
For additional information about zoning, see the “Information About Zoning” section on page 38-1.
NPV Traffic Management
Cisco Nexus 5000 Series switches provide NPV traffic management features. This section describes
NPV traffic management and includes the following topics:
• Automatic Uplink Selection, page 34-4
• Traffic Maps, page 34-4
• Disruptive Load Balancing, page 34-4
Automatic Uplink Selection
NPV supports automatic selection of NP uplinks. When a server interface is brought up, the NP uplink
interface with the minimum load is selected from the available NP uplinks in the same VSAN as the
server interface.
When a new NP uplink interface becomes operational, the existing load is not redistributed automatically
to include the newly available uplink. Server interfaces that become operational after the NP uplink can
select the new NP uplink.
Traffic Maps
In Release 4.0(1a)N2(1) and later software releases, NPV supports traffic maps. A traffic map allows
you to specify the NP uplinks that a server interface can use to connect to the core switches.
Note When an NPV traffic map is configured for a server interface, the server interface must select only from
the NP uplinks in its traffic map. If none of the specified NP uplinks are operational, the server remains
in a non-operational state.
The NPV traffic map feature provides the following benefits:
• Facilitates traffic engineering by allowing configuration of a fixed set of NP uplinks for a specific
server interface (or range of server interfaces).
• Ensures correct operation of the persistent FC ID feature, because a server interface will always
connect to the same NP uplink (or one of a specified set of NP uplinks) after an interface
reinitialization or switch reboot.
Disruptive Load Balancing
In Release 4.0(0)N1(2a) and later software releases, NPV supports disruptive load balancing. When
disruptive load balancing is enabled, NPV redistributes the server interfaces across all available NP
uplinks when a new NP uplink becomes operational. To move a server interface from one NP uplink to
another NP uplink, NPV forces reinitialization of the server interface so that the server performs a new
login to the core switch.
Only server interfaces that are moved to a different uplink are reinitialized. A system message is
generated for each server interface that is moved.