elmurci@elmurci-desktop:~$ sudo umount /dev/sdb1
umount: /media/KINGSTON: device is busy.
        (In some cases useful info about processes that use
         the device is found by lsof(8) or fuser(1))
elmurci@elmurci-desktop:~$ sudo umount /dev/sdb
umount: /dev/sdb: no montado
elmurci@elmurci-desktop:~$