Brocade FICON Administrator's Guide v7.1.0 (53-1002753-01, March 2013)

30 FICON Administrator’s Guide
53-1002753-01
Automating CS_CTL Mapping
2
3. Enter ficonClear rnid to remove all the RNID records marked “not current” from the local RNID
database.
Automating CS_CTL Mapping
The CS_CTL-based frame prioritization feature allows you to prioritize the frames between a host
and target as having high, medium, or low priority, depending on the value of the CS_CTL field in
the FC frame header. High, medium, and low priority frames are allocated to different virtual
channels (VCs). High priority frames receive more VCs than medium priority frames, which receive
more VCs than low priority frames. The virtual channels are allocated according to the CS_CTL
value.
NOTE
Check with your host and storage manufacturer to determine if they support Fibre Channel CS_CTL
prioritization on their devices.
The Fabric OS Administrator's Guide provides additional information on this feature and steps to
enable CS_CTL-based frame prioritization on your switch using the portcfgqos command.
The configurechassis command allows you to set chassis-level configuration parameters, such as
cfgload, custom, system, and Fabric OS attributes, to be used by ASIC drivers. The following
procedure uses the Fabric OS attribute, CSCTL QoS Mode, to change CSCTL values mapped to VCs
for priority levels from default to auto mode. While default mode maps CSCTL values 1-8 (low), 9-16
(medium), and 17-24 (high) to specific VCs, auto mode maps CSCTL values 1 (low), 2 (medium),
and 3 (high) to VCs based on the ASIC supported by your platform. For DCX 8510-4, DCX 8510-8,
and 6510 models, a single CSCTL value is mapped to multiple VCs.
To enable auto mode for CSCTL-VC mapping on a FICON switch, use the following steps.
NOTE
This process is disruptive as you must reboot the chassis to reset the configuration in the ASIC. You
cannot enable CS_CTL mapping on individual ports until this is done. If Auto Mode is selected, you
must select Auto Mode for each chassis in the fabric. Not doing so will mean different virtual
channels (VCs) will be used across the fabric with undesirable results.
1. Connect to the switch and log in to an account that has admin permissions.
2. Launch the configurechassis command.
3. Select no when prompted to modify cfgload attributes, custom attributes, and system
attributes, then select yes to modify Fabric OS attributes as in the following example:
root> configurechassis
Configure...
cfgload attributes (yes, y, no, n): [no]
Custom attributes (yes, y, no, n): [no]
system attributes (yes, y, no, n): [no]
fos attributes (yes, y, no, n): [no] y
4. Select 1 (auto mode) when prompted to configure CSCTL QoS Mode as in the following
example:
CSCTL QoS Mode (0 = default; 1 = auto mode): (0..1) [0] 1