You cannot; the OVF spec has no way to specify this. You can ask this question over on the OVF forum; they may have future plans to support this.
t should be deployed with thick provisioning for perfomance reasons.
This is a little silly - modern versions of the hypervisor show almost no performance difference between thick and thin for 99% of workloads.
Ok, thank you for the answer.
Conpletely agree with Matt. I Recently ran some IO tests on a thick vs thin provisioning, and I saw no difference between them.. Go thin