Dell POWEREDGE M1000E - Manual (Page 37)

Fabric Watch Administrator’s Guide 17
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Fabric Watch alarm behavior
2
Figure 4 shows a sample graph of data obtained by Fabric Watch (the type of data is irrelevant to
the example). A high threshold of 2 is specified to trigger an event. A time base of minute is
defined. An event occurs only if the rate of change in the specific interval (one minute in this
example) is across the threshold boundary. It should be either higher than the high threshold limit
or lower than the low threshold limit.
As illustrated on the tenth sample, the counter value changes from 0 to 1; hence calculated rate of
change is 1 per minute. At the thirteenth sample, the rate of change is 2 per minute. The rate of
change must be at least 3 per minute to exceed the event-triggering requirement of 2, which is met
on the eighteenth sample.
FIGURE 4 Event trigger
Fabric Watch alarm behavior
Fabric Watch alarm behavior depends on the threshold states associated with the Above, Below
and Changed thresholds. Threshold states can be INFORMATIVE, IN_RANGE, and OUT_OF_RANGE.
Notifications are generated only for the following transitions:
• IN_RANGE to OUT_OF_RANGE
• OUT_OF_RANGE to IN_RANGE
No alarm is generated for INFORMATIVE to IN_RANGE (or IN_RANGE to INFORMATIVE).