This particular system has 6 volumes & 3 aggregates (16TB capacity). The system is running Data ONTAP 7.2.3. They have noticed that the spike is occurring when they are on the dashboard page & is due to the performance charts.
I've suggested to the customer that they see if they experience the same condition when using "Filer-At-A-Glance" on the same system. However, they would like to see an option to turn off/on the performance charts and adjust the polling interval.
Ken