HP StorageWorks Fabric OS 6.1.1 administrator guide (5697-0235, December 2009)

Fabric OS 6.1.x administrator guide 309
Limitations and restrictions for traffic prioritization
Note the following configuration rules for traffic prioritization:
• If a host and target are included in two or more QoS zones with different priorities, the zone with the
lowest priority takes precedence. For example, if an effective zone configuration has QOSH_z1 (H,T)
and QOSL_z2 (H,T), the traffic flow between H and T will be of low QoS priority.
Additionally, if QOSH_z1 (H,T) overlaps with a domain,port zone at the H port, the traffic flow
between H and T is dropped to medium priority and the H port is marked as a session-based soft
zoning port.
• Traffic prioritization is enforced on the egress ports only, not on the ingress ports.
• Traffic prioritization is not supported on 10 Gbps ISLs.
• Traffic prioritization is not supported on mirrored ports.
• If QoS is enabled, an additional 16 buffer credits are allocated per port for 8-Gbps ports in LE mode.
See ”Administering extended fabrics” on page 359 for information about buffer credit allocation in
extended fabrics.
• Trunking considerations: If some ports in a trunk group have QoS enabled and some ports have QoS
disabled, two different trunks are formed, one with QoS enabled and one with QoS disabled.
• Traffic prioritization is enforced on the egress ports only, not on the ingress ports.
Setting traffic prioritization
1. Connect to the switch and log in as admin.
2. Issue the zoneCreate command with the following syntax:
zonecreate "QOSp_zonename", "member[; member...]"
where:
• p is the priority of the traffic. Possible values are:
• H for high priority
• L for low priority
• zonename is the user-defined part of the name of the zone to be created.
• member is a member or list of members to be added to the zone. A zone member must be specified
using WWN only.
3. Issue the cfgAdd command to add the QoS zone to the zone configuration, using the following syntax:
cfgadd "cfgname", "QOSp_zonename"
where:
• cfgname is the name of the zone configuration
• QOSp_zonename is the name of the QoS zone to be added to the configuration.
4. Issue the cfgSave command to save the change to the defined configuration.
5. Issue the cfgEnable command for the appropriate zone configuration to make the change effective:
cfgenable "cfgname"
where: cfgname is the name of the zone configuration.
6. Issue the portCfgQos command to enable QoS on the E_Ports, using the following syntax:
portcfgqos --enable [slot/]port
where:
• slot/port is the slot and port number of the E_Port on which you want to enable QoS. The slot
number is required for a 4/256 SAN Director or DC Director.