Disabling Restrictions On Oversubscription Ratios - Cisco MDS 9000 Series Configuration Manual

Configuring Module Interface Shared Resources
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
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Interfaces in the Port-Group
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fc8/7
fc8/8
fc8/9
fc8/10
fc8/11
fc8/12
...
When disabling restrictions on oversubscription ratios, all ports in shared mode on 48-port and 24-port
4-Gbps or any 8-Gbps Fibre Channel switching modules must be shut down. When applying restrictions
on oversubscription ratios, you must take shared ports out of service.
Note When restrictions on oversubscription ratios are disabled, the bandwidth allocation among the shared
ports is proportionate to the configured speed. If the configured speed is auto on Generation 2 modules,
then bandwidth is allocated assuming a speed of 4 Gbps. For example, if you have three shared ports
configured at 1, 2, and 4 Gbps, then the allocated bandwidth ratio is 1:2:4.
As of Cisco SAN-OS Release 3.0 and NX-OS Release 4.1(1) or when restrictions on oversubscription
ratios are enabled, the port bandwidths are allocated in equal proportions, regardless of port speed, so,
the bandwidth allocation for the same three ports mentioned in the example would be 1:1:1.

Disabling Restrictions on Oversubscription Ratios

Before disabling restrictions on oversubscription ratios, ensure that you have explicitly shut down shared
ports. To disable restrictions on oversubscription ratios on a 48-port or 24-port 4-Gbps, or any 8-Gbps
Fibre Channel switching module, follow these steps:
Command
Step 1
switch# config t
switch(config)#
Step 2
switch(config)# no rate-mode
oversubscription-limit module 1
Step 3
switch(config)# exit
Step 4
switch# copy running-config startup-config
Use the show running-config command to view oversubscription ratios for a module. If
oversubscription ratios are enabled, then no restriction appears in the output.
Example 3-1
switch# show running-config
version 3.1(1)
...
Cisco MDS 9000 Family NX-OS Interfaces Configuration Guide
3-28
Module with Restrictions on Oversubscription Ratios Disabled
Chapter 3
B2B Credit Bandwidth
Buffers (Gbps)
16 4.0
16 4.0
16 4.0
16 4.0
16 4.0
16 4.0
Purpose
Enters configuration mode.
Disables restrictions on oversubscription ratios for a
module.
You must enter this command separately for
Note
each module for which you want to remove
the restrictions.
Exits configuration mode.
Saves the new oversubscription ratio configuration
to the startup configuration, and then the new
configuration is enforced upon subsequent reboots
of the module.
OL-19445-02, Cisco MDS NX-OS Release 4.2(x)
Configuring Fibre Channel Interfaces
Rate Mode
dedicated
dedicated
dedicated
shared
shared
shared