There were many discussion over storage UNMAP via thin provisioning and many called it a "myth". This was also discussed heavily in our Facebook VMUG - ASEAN group. This was due to many changes since VMFS3 to till VMFS5. Cody wrote a long history of what are the changes for those who have missed out here.
A KB was also release and this create some discussion VMFS3 with different block size would benefit thin provision so to speak before vSphere 5.0 Update 1. Sadly after which, all UNMAP was not possible via GUI or automatically other than via command line or script.
I try to ask internally as well and luckily Cormac with his findings has listed all the…