Mac OS X in a Nutshell

Starting Up and Logging In

When you turn on your Mac (or restart it), it spends a couple of minutes or so initializing various processes to ready the machine for user login, as well as whatever network service it may provide (see Chapter 7). Unix veterans are used to seeing this phase as a cascade of messages spilling down a text console, but Mac OS X hides all this information behind a plain white screen with a plain gray Apple logo on it.

Tip

You can see all that startup text if you really want to, by booting into single-user mode, as described in Chapter 11. This can be a useful diagnostic tool for hardcore Unix-heads who know what they’re doing, or a way for the merely curious to watch the strange sight of their Mac rolling out of bed and stumbling around in pure-Unix mode before it puts on its Mac OS face. Use the exit command at the single-user shell to resume the normal Mac OS X boot process.

You may also view some of the machine’s startup messages after the fact by looking at the file /var/log/system.log. (Note that only users with admin access can read the file.)

Eventually the system either settles on the login screen, or goes ahead to log in a specific user, depending upon the machine’s configuration. In the former case, you’ve got to provide your username (either by choosing it from a list or typing it in—again, based on configuration settings in the Accounts preference pane) and password before you can continue into the Finder, whereupon you can actually start using ...