Configuring Generation 2 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
When disabling restrictions on oversubscription ratios, all ports in shared mode on 48-port and 24-port
4-Gbps Fibre Channel switching modules must be shut down. When applying restrictions on
oversubscription ratios, you must take shared ports out of service.
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, 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. In Cisco SAN-OS Release 3.0 and later (or when
restrictions on oversubscription ratios are enabled), 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 Fibre Channel
switching module, follow these steps:
switch# config t
switch(config)# no rate-mode
oversubscription-limit module 1
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 14-1 Module with Restrictions on Oversubscription Ratios Disabled
switch# show running-config
no rate-mode oversubscription-limit module 2
switchport speed 2000
Cisco MDS 9000 Family CLI Configuration Guide
Configuring Generation 2 Switches and Modules
Enters configuration mode.
Disables restrictions on oversubscription ratios for a
You must enter this command separately for
each module for which you want to remove
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-16184-01, Cisco MDS SAN-OS Release 3.x