and when i check in our esxi 5 version one of vm m/c i could not able to located file vmname.vmdk disk descrriptor file.(test file) but able to locate flat.vmdk(binary file).
The files you described are correct. If there's no descriptor file for a virtual disk, then you need o recreate it in order to use the virtual disk. Can you please provide some details about this, e.g. a screen shot.
André
