Though i dont know, what is the cause of the missing mapping or some file system corruption happended that i was not able to see the internal storage.
after performing the steps as in my below post. it started detecting the drive.
not sure of the rootcause of this problem, but i found a solutions for this. even though the problem may recurr in future.
WD TV live team to please investigate this error and fix in coming future firmware upgrades…
