#vbox
VBoxManage clonehd T13.vdi t.vmdk --format vmdk --variant standard
0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100%
Clone medium created in format 'vmdk'. UUID: d26df585-6358-454d-aec2-8ee09bb40643

#esxi
vmkfstools -d thin -i t.vmdk t13.vmdk
Destination disk format: VMFS thin-provisioned
Cloning disk 't.vmdk'...
Clone: 100% done.