Thanks!
Yes I see that and it is intentional, I have a file server that basically has that VMFS volume dedicated to it. It just has a single VMDK on it. In any case there is still 7GB of space left, and that file system is not what is used for /var or /sbin for that matter on the ESXi host. In my tests I'm trying to write a mere 20MB worth of data.
Also the space on that VMFS volume has been unchanged for more than one year, the VMFS file is thick provisioned.
nate