vmkfstools -i newheader.vmdk -d thin test.vmdk If the disk is too corrupt for mounting:
(works for single-file growable VMDK)
vmkfstools -x repair /vmfs/volumes/datastore1/VM/VM-flat.vmdk If repair fails, clone the VMDK while forcing consistency checks: recover data from corrupt vmdk
vmware-vdiskmanager -d /path/to/your.vmdk vmware-vdiskmanager -k /path/to/your.vmdk If the VMDK is not recognized as a disk but contains intact data blocks: vmkfstools -i newheader