How to keep NPM Interface Utilization charts longer without being averaged after 7 days

Hi All,

I want to know if we can or how to keep the granular data of interface utilization charts over the standard 7 days. At the moment I've configured for NPM to poll the interfaces on a per minute basis (rather than the default 9 minutes I think it was).

Because every time we go past the 7 days mark, it gets averaged out to 12 hours or once a day rather than per minute basis. May not be advisable, but I want to try 2 weeks or up to a month.

This is NPM Summary > Select a Node > Current Percent Utilization of Each Interface, then select any interface charts.

Thanks