9

I would like to monitor the messages generated when I boot my Mac, similar to what you on a *nix box. Is there key-combo to press/hold that will let me do this?

2 Answers 2

11

You have to press cmd + v upon startup to see the boot output. Press this right after the chime.

If you want to make that permanent, you should probably do something along the lines of:

sudo nvram boot-args="-v"

To undo the above:

sudo nvram boot-args=

in the Terminal. (/Applications/Utilities/Terminal.app)

note: I haven’t tested the above commands, but I’m sure a google query will help you there if you want to make it permanent.

4
  • 3
    I can hardly wait to try this. I hate staring at the apple on boot.
    – chiggsy
    Commented Nov 24, 2010 at 3:29
  • 1
    Why? What's wrong with it? Commented Feb 12, 2011 at 9:55
  • As a Linux user, I am used to reading log messages during startup. They are far more interesting than a boring progress bar. Now that I've bought my first iMac, I'm pleased to have startup log messages on it too.
    – Christoph
    Commented Apr 8, 2023 at 17:11
  • boot-args allow much more, for instance not sleeping when closing the lid, despite having no external monitor, see: apple.stackexchange.com/a/301847/266584 Commented Jun 5 at 21:16
2

If you want to see the boot messages after the boot occurred, log in and run sudo dmesg in Terminal.app.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .