Installation guide

Table 21-22 lists the command-line substitution parameters for scripts that run as alarm actions.
Table 21-22. Command-Line Parameters for Alarm Action Scripts
Variable Description
{eventDescription}
Text of the alarmStatusChange event. The {eventDescription} variable is
supported only for Condition and State alarms.
{targetName}
Name of the entity on which the alarm is triggered.
{alarmName}
Name of the alarm that is triggered.
{triggeringSummary}
Summary info of the alarm trigger values.
{declaringSummary}
Summary info of the alarm declaration values.
{oldStatus}
Alarm status before the alarm is triggered.
{newStatus}
Alarm status after the alarm is triggered.
{target}
Inventory object on which the alarm is set.
Alarm Reporting
Alarm reporting further restricts when a condition or state alarm trigger occurs by adding a tolerance range
and a trigger frequency to the trigger configuration.
Tolerance Range
The tolerance range specifies a percentage above or below the configured threshold point, after which the alarm
triggers or clears. A nonzero value triggers and clears the alarm only after the triggering condition falls above
or below the tolerance range. A 0 (zero) value triggers and clears the alarm at the threshold point you
configured.
vCenter Server uses the following calculation to trigger an alarm:
Condition threshold + Tolerance Range = Trigger alarm
For example, an alarm is defined to trigger a warning state when a host’s CPU usage is above 70%. If you set
the tolerance range to 5%, the warning state triggers only when CPU usage is above 75% (70 + 5) and resets to
a normal state only when CPU usage falls below 65% (70 - 5).
The tolerance range ensures you do not transition alarm states based on false changes in a condition.
Trigger Frequency
The trigger frequency is the time period during which a triggered alarm action is not reported again. When
the time period has elapsed, the alarm action occurs again if the condition or state is still true. By default, the
trigger frequency for the default VMware alarms is set to 5 minutes.
For example, if the Host CPU Usage alarm triggers for a warning state at 2 p.m. and an alert state occurs at
2:02 p.m, the alert state is not reported at 2:02 p.m. because the frequency prohibits it. If the warning state is
still true at 2:05 p.m., the alarm is reported. This guards against repeatedly reporting insignificant alarm
transitions.
Creating Alarms
Creating an alarm involves setting up general alarm settings, alarm triggers, trigger reporting, and alarm
actions.
Required Privilege: Alarms.Create Alarm
Chapter 21 Working with Alarms
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