Use alarms for proactive monitoring.
vCenter Server offers extensive alarms for alerting vSphere administrators to excessive resource consumption or potentially negative events. You can create alarms on virtually any type of object found within vCenter Server, including datacenters, clusters, ESX/ESXi hosts, and virtual machines. Alarms can monitor for resource consumption or for the occurrence of specific events. Alarms can also trigger actions, such as running a script, migrating a virtual machine, or sending a notification email.
What are the questions a vSphere administrator should ask before creating a custom alarm?
You should ask several questions before you create ...