Programmatically, I'm not sure. But in Windows you can associate a drive letter to a disk number, then out in VMware you can associate a disk number to a VMDK filename.

That file stores all the writes that the virtual machine makes after the snapshot is taken. Having this second VMDK file absorbing the writes for the virtual machine has several important ...

The boilerplate answer is to shrink the VMDK... but these Linux VMs use an ext4 filesystem, which VMware does not support shrinking with their conventional tools (i.e. vmware-toolbox).