Cisco Nexus 5000 Series Switch CLI Software Configuration Guide (OL-16597-01, July 2009)

• An autocreated SAN port channel is not persistent through a reboot. An autocreated SAN port channel
can be manually configured to appear the same as a persistent SAN port channel. Once the SAN port
channel is made persistent, the autocreation feature is disabled in all member ports.
• You can enable or disable the autocreation feature on a per-port basis or for all ports in the switch. When
this configuration is enabled, the channel group mode is assumed to be active. The default for this task
is disabled.
• If autocreation of channel groups is enabled for an interface, you must first disable autocreation before
downgrading to earlier software versions or before configuring the interface in a manually configured
channel group.
When enabling autocreation in any switch in the Cisco Nexus 5000 Series, we recommend that you retain
at least one interconnected port between the switches without any autocreation configuration. If all ports
between two switches are configured with the autocreation feature at the same time, a possible traffic
disruption may occur between these two switches as ports are automatically disabled and reenabled when
they are added to an autocreated SAN port channel.
Tip
Enabling and Configuring Autocreation
To configure automatic channel groups, perform this task:
Procedure
PurposeCommand or Action
Enters configuration mode.switch# configuration terminal
Step 1
Enters configuration mode for the specified interface.
switch(config)# interface type slot/port
Step 2
Automatically creates the channel group for the
selected interface(s).
switch(config- if)# channel-group auto
Step 3
Disables the autocreation of channel groups for this
interface, even if the system default configuration
may have autocreation enabled.
switch(config- if)# no channel-group
auto
Step 4
Example of Configuring Autocreation
The following example configures an automatic channel group:
switch(config)# interface fc2/3
switch(config-if)# channel-group auto
About Manually Configured Channel Groups
A user-configured channel group cannot be converted to an autocreated channel group. However, you can
convert an autocreated channel group to a manual channel group. This task is irreversible. The channel group
number does not change, but the member ports operate according to the properties of the manually configured
channel group, and channel group autocreation is implicitly disabled for all the member ports.
If you enable persistence, be sure to enable it at both ends of the SAN port channel.
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
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Configuring SAN Port Channels
Enabling and Configuring Autocreation