HP Cisco Nexus 5000 Cisco MDS 9000 Family CLI Configuration Guide - Release 4. - Page 1366

Example Configuration Chapter 56 Configuring Fabric Congestion Control and QoS Send documentation comments to [email protected] Example 56-10 Displays the Class Map Associated with a Specified Interface switch# show qos service policy interface fc3/10 qos policy-map pmap1 class cmap3 priority high class cmap4 priority low Example 56-11 Displays QoS Statistics switch# show qos statistics Total number of FC frames transmitted from the Supervisor= 301431 Number of highest-priority FC frames transmitted = 137679 Current priority of FC control frames = 7 (0 = lowest; 7 = highest) Example Configuration This section describes a configuration example for the application illustrated in Figure 56-3. Figure 56-3 Example Application for Traffic Prioritization OLTP server 21:00:00:0c:50:02:ca:b5 Disk 22:00:00:04:cf:22:eb:dc FC Congestion Backup server VOQ(s) Absolute VOQ(s) Absolute High 21:00:00:0c:50:02:c7:ff Medium Low High Medium Low 130667 Switch 1 Switch 2 Both the OLTP server and the backup server are accessing the disk. The backup server is writing large amounts of data to the disk. This data does not require specific service guarantees. The volumes of data generated by the OLTP server to the disk are comparatively much lower but this traffic requires faster response because transaction processing is a low latency application. The point of congestion is the link between Switch 2 and the disk, for traffic from the switch to the disk. The return path is largely uncongested as there is little backup traffic on this path. Service differentiation is needed at Switch 2 to prioritize the OLTP-server-to-disk traffic higher than the backup-server-to-disk traffic. To configure traffic prioritization for the example application, follow these steps: 56-12 Cisco MDS 9000 Family CLI Configuration Guide OL-18084-01, Cisco MDS NX-OS Release 4.x