VMWare ESXi 5.5, thin provision still allocates full amount of space on disk

Solution 1:

This is because thin-provisioned files in ESXi are sparse files. The method you're using to move them around won't preserve that thin attribute.

There are ways around this. Please see: Move VMware ESXi VM to new datastore - preserve thin-provisioning

Solution 2:

That hundred gig file is a sparse file - there's nothing in it, the filesystem simply knows that's the intended size.

You can see the real size in the vSphere client:

..despite the apparent size when you're looking at the raw files..

The problem you're having is that you're removing that file from the VMFS filesystem. Wherever it's going and however it's getting there, the sparse file is only sparse as long as it's on VMFS; ESXi is forced to feed you the full apparent file, with all those extra 0s.

Storage vMotion and vmkfstools will handle thin disks correctly if you're moving between ESXi hosts; exporting to OVF is another good option for not moving around the full thick disk.

Generally speaking, you should avoid trying to work directly with the flat files, instead using the proper tools to move or clone the logical VMDK (which might have flat files, snapshots, etc).