Brocade Fabric OS Command Reference - Supporting Fabric OS v7.0.1 (53-1002447-01, March 2012)

Fabric OS Command Reference 681
53-1001764-01
portCfgQoS
2
portCfgQoS
Enables or disables QoS, sets the default configuration, and sets and resets the ingress rate limit.
SYNOPSIS portcfgqos --disable | --enable [slot/]port
portcfgqos --setratelimit [slot/]port ratelimit
portcfgqos --resetratelimit [slot/]port
portcfgqos --enable | --disable [slot/]port[-port] csctl_mode
portcfgqos --default [slot/]port
portcfgqos --help
DESCRIPTION Use this command to configure traffic prioritization on a port. Two alternate modes of traffic prioritization
are supported by this command: Adaptive Networking/Quality of Service (AN/QoS) or Class-Specific
Control (CS_CTL):
• The Adaptive Networking with QoS feature allows latency-sensitive applications to share storage
resources alongside throughput-intensive applications. You can enable or disable Adaptive
Networking/Quality of Service (AN/QoS) on a port, set or reset the ingress rate limit for the specified
port, and set the default behavior. Ingress Rate Limiting delays the return of BB credits to the
external device. By limiting the throughput on the ingress side of a port, existing congestion can be
removed or avoided.
• In Fabric OS v7.0.0 and later, an alternate method of traffic flow prioritization based on the CS_CTL
bits of a Fibre Channel frame is provided through this command. This feature uses the value of the
CS_CTL bit of the frame to determine the virtual channel (VC), so each frame can be prioritized
based on the value of the CS_CTL bit.
CS_CTL flow prioritization is independent of traffic prioritization based on QoS zones; and both methods
are mutually exclusive. If CS_CTL VC mode is enabled on an F/FL_Port, QoS-based traffic flow
prioritization cannot be used between any two devices connected to these F/FL_Ports in that fabric and
vice versa.
If both QoS-based and CS_CTL-based traffic prioritization are enabled on the same F/FL_Port, the
CS_CTL-based method takes priority over the QoS zones. When QoS is enabled on an F/FL_Port and
you enable CS_CTL VC mode on the same port, the command displays a message stating that QoS
zones will lose priority to CS_CTL-based traffic prioritization. When you disable CS_CTL mode on a
given F/FL port, the QoS zones, if already enabled, become the effective frame classification method for
all devices connected to that F/FL_Port.
NOTES The execution of this command is subject to Virtual Fabric or Admin Domain restrictions that may be in
place. Refer to Chapter 1, "Using Fabric OS Commands" and Appendix A, "Command Availability" for
details.
Enabling and disabling QOS is potentially disruptive to the I/O on the affected port.
An Adaptive Networking license is required for using this command.
This command is not supported on all platforms. Refer to the Fabric OS Administrator's Guide for more
information.
The configuration changes effected by this command are persistent across system reboots.
The Fabric OS port configuration commands are not supported on FCoE ports.