Configuring Buffer-To-Buffer Credits; About Performance Buffers - Cisco MDS 9000 Series Configuration Manual

About Performance Buffers

S e n d d o c u m e n t a t i o n c o m m e n t s t o m d s f e e d b a c k - d o c @ c i s c o . c o m
In the Cisco MDS 9100 Series, the groups of ports on the left outlined in white are in dedicated rate
Note
mode. The other ports are host-optimized. Each group of 4 host-optimized ports have the same features
as for the 32-port switching module.

Configuring Buffer-to-Buffer Credits

To configure BB_credits for a Fibre Channel interface, follow these steps:
Command
Step 1
switch# config t
switch(config)#
Step 2
switch(config)# interface fc1/1
switch(config-if)#
Step 3
switch(config-if)# switchport fcrxbbcredit
default
switch(config-if)# switchport fcrxbbcredit 5
switch(config-if)# switchport fcrxbbcredit 5
mode E
switch(config-if)# switchport fcrxbbcredit 5
mode Fx
Step 4
switch(config-if# do show int fc1/1
This example shows the output of the show int fc1/1 command:
intfc1/1 is up
About Performance Buffers
Performance buffers are not supported on the Cisco MDS 9124 Fabric Switch, the Cisco Fabric Switch
Note
for HP c-Class BladeSystem, and the Cisco Fabric Switch for IBM BladeCenter.
Cisco MDS 9000 Family NX-OS Interfaces Configuration Guide
4-2
...
16 receive B2B credit remaining
3 transmit B2B credit remaining
Chapter 4 Configuring Interface Buffers
Purpose
Enters configuration mode.
Selects a Fibre Channel interface and enters
interface configuration submode.
Applies the default operational value to the
selected interface. The operational value depends
on the port mode. The default values are assigned
based on the port capabilities.
Assigns a BB_credit of 5 to the selected interface.
The range to assign BB_credits is between 1 and
255.
Assigns this value if the port is operating in E or
TE mode. The range to assign BB_credits is
between 1 and 255.
Assigns this value if the port is operating in F or
FL mode. The range to assign BB_credits is
between 1 and 255.
Displays the receive and transmit BB_credit
along with other pertinent interface information
for this interface.
Note The BB_credit values are correct at the
time the registers are read. They are
useful to verify situations when the data
traffic is slow.
OL-19445-02, Cisco MDS NX-OS Release 4.2(x)