In some cases, you might want to remove obsolete alarm actions and triggers.

Connect to a vSphere server.

1

Remove the first one from the action triggers found for an alarm definition.

Get-AlarmDefinition -Name AlarmDefinition | Get-AlarmAction | Get-AlarmActionTrigger | select -First 1 | Remove-AlarmActionTrigger -Confirm:$false
2

Remove all the actions for an alarm definition.

Get-AlarmDefinition -Name AlarmDefinition | Get-AlarmAction | Remove-AlarmAction -Confirm:$false