We can make mac to boot in verbose mode permanently (i.e, show all log messages during boot) by setting the " nvram " variable in terminal. $ sudo nvram boot-args="-v" This will set the mac to show verbose messages when every time mac os x boots. To reset back again, run : $ sudo nvram boot-args= Note : If you want to see the verbose messages for momentarily then hold " Command+V " during the mac booting immediately after mac starts booting