This article covers how to manage space utilization in Data ONTAP SAN environment. You can get information on storage efficiency, space guarantee, space allocation in an aggregate, snapshot of a LUN,...This article covers how to manage space utilization in Data ONTAP SAN environment. You can get information on storage efficiency, space guarantee, space allocation in an aggregate, snapshot of a LUN, LUN space reservation and snapshot copy reserve. It also cover the options if you are running out of space.