HP StorageWorks 2.140 Director Switch - Manual (Page 195)

Director Element Manager user guide 195
NOTE: You must either specify a value in the Threshold % column or click the Use
Algorithmic Threshold check box.
5. Set Event Notification options.
Note that if enabled event notifications occur the first time an event occurs. Notifications are not
re-sent while the problem persists.
• Unresolved Congestion. Click this check box to enable notification.
If enabled, an unresolved congestion entry is made to the Event Log and an SNMP trap is
generated if trap recipients are configured through the Configure SNMP dialog box.
NOTE: An unresolved congestion event occurs when the rerouting algorithm cannot find a
path for rerouting data flow and relieving congestion on an ISL.
• Back Pressure. Click this check box to enable this option.
If enabled, a back pressure entry will be made to the Event Log. An SNMP trap will be
generated if trap recipients are configured through the Configure SNMP dialog box.
NOTE: A back pressure event occurs when the percentage of time the ISL lacks BB_Credits
exceeds the threshold. A separate event also occurs when the backpressure condition ends.
6. Set the Low BB Credit Threshold:
NOTE: Using default settings for this threshold should work well in most cases. This step is
not required.
This is the percentage of time that the transmitting link cannot transmit because BB_Credit is
unavailable. It is also the percentage of time that the link can be treated as back-pressured by
the rerouting algorithm. This value is also used when determining routes for a transmit link. A
back-pressured ISL cannot be the recipient of traffic rerouted from other ISLs, and traffic on a
back-pressured ISL may be rerouted even if the ISL is not congested.
• Click Default Threshold and a default value (1 to 99%) is displayed in the Threshold
box.
If the default is enabled, you cannot enter values into the box.
• Click in the threshold box and enter a value from 1 to 99.
7. Click Activate.