alexk2016 , Sorry the limitation you're hitting isn't Isilon-specific, it'll happen on any NFS storage target with ESX, thin is always the only option. Here is a vmware community thread on the subject: [URL]  ~Chris Klosterman Advisory Solution Architect EMC Enablement Team chris.klosterman[NAME].com
Hi,  i have installed the EMC_Isilon_OneFS_8.0.0.0_Simulator on my ESXi 5.5 Server. Now i have created a NFS Share on it and added the Share to the Datastore of the ESX Server.  Now i want to create a virtual hard drive with Thick Provisioning but i can't chose it,  always change it automatically to thin provisioning. Is it the Hardware acceleration(it is not supported)? Is it possible to activate the hardware acceleration on the virtual emc isilon oneFS or is it the wrong way to get a hard drive with thick provisioning? Can someone help me with my problem? :-) Thanks.
EMC Isilon OneFS