VM Host level Capacity reporting

Hi all

I am looking for ideas/products/solutions to do some chargeback reporting for a client who has various EMC storage devices and is running VMware and VIOS.I believe it is straightforward to get capacity details at the ESX Host level but customer wants to do chargeback at the vm level. The client has grouped their virtual machines into Busines Units and want to do chargeback at the BU level.

The customer is today using ECC but agent coverage is poor. We cannot propose deploying agents to each vm to understand how much disk has being presented to the vm's.

Host environment is a mix of Wintel and Unix.

Any advice appreciated.

BR

Steve