VMware vSphere 4 and 5 has a powerful alerting / notification system built in called “Alarms”. Sometimes you may notice the alarm indicators are reporting incorrectly and therefore need to be manually reset.
By default vpshere has 33 pre-configured and enabled alarms. All of these pre-configured alarms are configured at the highest level (on the vCenter server). To reset the vSphere datastore alarms:
Login to Vsphere Client
First identify the name of the alarm to wish to reset. In this example I will use “ Datastore Usage on Disk”