What happens when cloning VM?

Hi,

Environment: vCenter 6.7 with ESXi 6.7 and datastores are NFS hosted by NetApp OnTAP 9.5

I have a VM in an NFS datastore and I need to clone it to another datastore. I use the same ESXi host to clone. The vmdk is 250GB thin-provisioned and the actual usage is only 10GB. When I look at the the file size on the NFS volume, it shows 250GB. Does it mean when I clone the VM, 250GB is copied? or only 10GB is copied?

Thanks,