Alarms signal the vCenter Server administrator about Guest Introspection events that require attention. Alarms are automatically cancelled in case the alarm state is no longer present.
vCenter Server alarms can be displayed without a custom vSphere plug-in. See the vCenter Server Administration Guide on events and alarms.
Upon registering as a vCenter Server extension, NSX Manager defines the rules that create and remove alarms, based on events coming from the three Guest Introspection components: SVM, Guest Introspection module, and thin agent. Rules can be customized. For instructions on how to create new custom rules for alarms, see the vCenter Server documentation. In some cases, there are multiple possible causes for the alarm. The tables that follow list the possible causes and the corresponding actions you might want to take for remediation.