vROPS allows you to see the active Guest Memory. Keep in mind that vRops collects statistics each 5 minutes.
From the “DIAGNOSE” tab , select a server
Go to the “METRIC PICKER”, select the metrics you want to display and set the “RANGE” in hours/days as you please.
Official VROPS page: Product Information Link
Official VROPS Documentation: Documentation Link
Official download page: Download here!