Disk usage / performance calculation
1. Calculate the optimal usage for a particular disk drive to maintain performance or calculate performance degradation based on information about the drive (areal density, size (TB), seek time, rotational velocity, etc.) and the % of disk space used assuming provisioning from the center outwards.
2. A cost/benefit calculation or method which given the cost of the disk space and an estimate of the cost of performance degradation (I'm not sure how to measure this) provides an estimate of the cost of that remaining disk space versus the cost of using it.
Goal: Provide management with information regarding the purchasing of disk when I see 80% utilization as beginning to impact performance and they see 80% as unused equipment they have already purchased. I need to be able to deliver hard numbers based on sound reasoning from reliable evidence. That "the tire salesman says we need new tires" doesn't work.