FW V05.01.00-24/HAFM SW V07.01.00-09 HAFM 1U Server SW V07.02.00-09 HP StorageWorks HA-Fabric Manager User Guide (AA-RS2CD-TE, September 2003)

Optional Features
194 High Availability Fabric Manager User Guide
■ Back Pressure — Click this check box to display a check mark and
enable this option. If enabled, a back pressure entry will be made to the
Event Log and an SNMP trap will be generated if trap recipients are
configured through the Configure SNMP dialog box.
A back pressure event occurs when the percentage of time the ISL has no
available BB_Credit exceeds the low BB_credit threshold. A separate
event also occurs when the backpressure condition ends.
5. Set the Low BB_Credit Threshold.
Note: Using default settings for low BB_Credit threshold should work well in most
cases. This step is not required.
Note: Earlier versions of this dialog box could display Credit Starvation Threshold
instead of Low BB_Credit Threshold.
The threshold value is the percentage of time that the transmitting link has no
BB_Credit. This value is also used when determining routes for a transmit
link. An ISL that has no BB_Credit for longer than this time percentage
cannot be the recipient of traffic rerouted from other ISLs. Traffic on this ISL
may be rerouted by Open Trunking even if the ISL is not congested.
Two options are available:
■ Click Default Threshold and a default value (1 to 99%) appears in the
threshold field. If the default is enabled, you cannot enter values into the
field.
■ Click in the threshold field and enter a value from 1 to 99.
6. Click Activate to enable these values on the switch and close the dialog box.