Cisco Systems DSC9148D8G48PK9 manual Bandwidth Allocation for Oversubscribed Interfaces

Chapter 3 Configuring Fibre Channel Interfaces

Information About Fibre Channel Interfaces

Table 3-9	Bandwidth Allocation for Oversubscribed Interfaces
			Reserved Bandwidth (Gbps)		Maximum
Switching					Bandwidth
Module		Configured Speed	Ratios enabled	Ratios disabled	(Gbps)
24-Port 8-Gbps		Auto 8 Gbps	0.8	0.8	8
Fibre Channel
		Auto Max 4 Gbps	0.4	0.4	4
Module
		Auto Max 2 Gbps	0.2	0.2	2
4/44-Port		8 Gbps	0.87	0.16	8
8-Gbps
		Auto Max 4 Gbps	0.436	0.08	4
Host-Optimized
		Auto Max 2 Gbps	0.218	0.04	2
Fibre Channel
Module		1 Gbps	0.109	0.02	1
48-port 4-Gbps		Auto 4 Gbps	0.8	0.09	4
Fibre Channel
		Auto Max 2 Gbps	0.4	0.045	2
switching
		1 Gbps	0.2	0.0225	1
module
24-port 4-Gbps		Auto 4 Gbps	1	0.27	4
Fibre Channel
		Auto Max 2 Gbps	0.5	0.135	2
switching
		1 Gbps	0.25	0.067	1
module

All ports in the 48-port and 24-port 4-Gbps modules can be configured to operate at 4 Gbps in shared mode even if other ports in the port group are configured in dedicated mode, regardless of available bandwidth. However, when oversubscription ratio restrictions are enabled, you may not have all shared 4-Gbps module ports operating at 4 Gbps.

All ports in the 48-port, 32-Port, and 24-port 8-Gbps modules can be configured to operate at 8 Gbps in shared mode even if other ports in the port group are configured in dedicated mode, regardless of available bandwidth. However, when oversubscription ratio restrictions are enabled you may not have all shared 8-Gbps module ports operating at 8 Gbps.

On the 48-port, 32-Port, and 24-port 8-Gbps modules, if you have configured one 8-Gbps dedicated port in one port group, no other ports in the same port group can be configured to operate at 8-Gbps dedicated mode. You can have any number of 8-Gbps shared and 4-Gbps dedicated or shared ports. On the 4/44-port 8-Gbps module, only one port per port group can be configured in 8-Gbps dedicated or shared mode.

In the following example, a 24-port 4-Gbps module has oversubscription ratios enabled and three dedicated ports in one port group operating at 4-Gbps. No other ports in the same port group can be configured to operate at 4 Gbps.

switch# show port-resources module 8 Module 8

Available dedicated buffers are 5478

Port-Group 1

Total bandwidth is 12.8 Gbps Total shared bandwidth is 0.8 Gbps Allocated dedicated bandwidth is 12.0 Gbps

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		Interfaces in the Port-Group	B2B Credit	Bandwidth	Rate Mode
			Buffers	(Gbps)
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		Cisco MDS 9000 Family NX-OS Interfaces Configuration Guide
	3-12				OL-29284-01, Release 6.x