Below Event Trigger; Changed Event Trigger; In-Between Triggers; Event Trigger - HP StorageWorks 2/64 - Core Switch Administrator's Manual

Below event trigger

The Below event trigger generates an event when a data value becomes less than the low threshold
boundary.
When a buffer is defined, the data value must be below the buffer value and the low threshold.

Changed event trigger

Use the Changed event trigger for an element that requires "rate of change" monitoring. When Fabric
Watch detects a change in the counter value between two sample periods (defined by the time base), it
triggers an event regardless of high or low threshold settings.
data value changes. Each arrow in the figure indicates a generated event.
Figure 7 Changed threshold
Use Changed event triggers with discretion. They are most useful when a change in value is expected to be
rare. Monitoring a fabric element that is subject to frequent change generates so many events that it can
render it virtually useless. For example, this trigger type is appropriate for FRU failures. It is not appropriate
for temperature monitoring.

In-Between triggers

Fabric Watch event triggers are usually set to notify the user of a warning or failure condition, but there is
an exception. You can define the In-Between trigger to receive a notification of fault recovery. For example,
when measuring port performance, crossing the high threshold triggers an Above threshold event, which
displays a warning message. The threshold might be crossed for a period so brief that is not a true cause
for an alarm. An In-Between trigger indicates that the port performance has returned to the acceptable
range.
Use the In-Between trigger to:
• Verify a successful recovery from a faulty condition.
• Reset the counter value for the next event.
• Identify an element that is consistently operating under marginal condition.
Figure illustrates event notification using an In-Between trigger. The arrow marked with one indicates the
point at which event notification occurs.
Figure 8 In-Between trigger
24 Fabric Watch concepts
Figure shows events generated when the