How to charge "used storage GB" - 50 GB?

Hi all,

My vCloud customer wants to charge his customer for using a base configuration in a Pay as You Go vDC.

The base config looks like this: 10 GB vRAM, 10 vCPU, 50 GB storage. The customer will be able to grow, everytime that he does that, the maximum vCPU, vRAM and storage will be enlarged aproximately.

Let's say the base config costs around 200 dollar and every vCPU extra costs .1 dollar per hour, the same for vRAM and for storage.

So if the vCD customer uses 70 GB of storage, I want Chargeback to charge with .1 dollar * 20 GB of storage per hour plus the base rate of 200 dollar per month.

I have looked at all the documentations and howtos but I was unable to find the answer.

Can somebody please help me?

Thanks in advance!

Peter Oudman.