Without the descriptor, partition table information may be missing. Use fdisk -l vmname-flat.vmdk to locate partitions.
vmkfstools -i /path/to/vm-flat.vmdk /new/path/recovered.vmdk -d thin vmware recover flat vmdk
This is the recommended method for production environments. It involves attaching the damaged flat VMDK to a healthy, functioning VM (the "Helper VM"). Without the descriptor, partition table information may be
Mount the flat VMDK as a loop device on a Linux VM or recovery appliance: Without the descriptor