Track utilization of a VMDK file

Hi,

I´m running vSphere 4.0 U1 (ESX) and wonder if there is a way to track the utilization of a default format VMDK file (zeroed thick?)?

The thing is we´re running thick VMDKs on thin storage, v-max (to only have one point of oversubscription to monitor) and now need a way to see which VMDK files are contributing to the growth of data inside the datastore. Right now we can only monitor the utilization of the actual LUNs.

Is there any such counters inside the vSphere stack, that can be queried through API or such? It feels to me that there might be something in the vStorage CBT area that could be useful.

This must be a common problem I think, but can´t find anything in the docs, forums or the knowledge base.

Thanks!

Regards,

Andreas