Lesson 29 Flashcards
What are the primary system initialization stages in OS X? What are the visual and audible cues of these items?
Each primary stage of system initialization can be indicated by the following: firmware, startup chime or bright flash of the power-on light, followed by a light gray screen on the primary display; booter, a dark gray Apple logo on the primary display; kernel, a small dark gray spinning gear or spinning earth icon below the Apple logo; and system launchd, a white screen on all displays followed by the login screen.
What does the firmware do? What’s the POST?
The firmware initializes the Mac computer’s hardware and locates the booter file on a system volume. The Power-On Self-Test (POST) checks for basic hardware functionality when the Mac powers on.
What role does the system launchd process serve during system startup?
The system launchd process is ultimately responsible for starting every system process. It also manages system initialization and starts the loginwindow process.
Which items are automatically started by the system launchd during the system initialization process?
During system initialization, the system launchd process automatically starts /System/ Library/LaunchDaemons, / Library/LaunchDaemons, /Library/StartupItems (via SystemStarter), and the /etc/rc.local UNIX script if it exists.
What are the primary user session stages in OS X? What are the visual and audible cues of these items?
Each primary stage of the user session can be indicated by the following: the loginwindow process displays the login screen; the user launchd process loads applications like the Finder after user authentication; and the user environment is active any time the user is logged into the system.
What’s the difference between launch daemons, startup items, launch agents, and login items?
Launch daemons and startup items open during system initialization by the system launchd process on behalf of the root user. Launch agents and login items open during the initialization of the user environment by the user’s specific
launchd process.
What are Safe Sleep and Power Nap?
Safe Sleep is a feature of all OS X compatible portable Macs that saves the system’s state to permanent storage in cases where the computer’s battery drains completely. Power Nap is a feature of Mac systems introduced after mid-2011 that use all-flash storage. Power Nap allows the Mac to automatically wake in a low-power mode so the system can perform a variety of application and system updates.
What happens during user logout?
During user logout, the user’s loginwindow process does the following: requests that all user applications quit; automatically quits any user background processes; runs any logout scripts; records the logout to the main system.log file; resets device permissions and preferences to their defaults; and quits the user’s loginwindow and launchd processes.
What happens during system shutdown?
At system shutdown, the loginwindow process logs all users out and then tells the kernel to quit all remaining system processes. Once the kernel quits all system processes, the Mac shuts down.
Which keyboard shortcut is used to Safe Boot OS X?
A Safe Boot is initiated by holding down the Shift key during system startup.
Which keyboard shortcut can be used to temporarily choose another startup disk?
Holding down the Option key at startup opens Startup Manager, which allows you to temporarily choose another startup disk.
Which changes are made when OS X Safe Boots?
A Safe Boot performs the following permanent actions: attempting to repair the system volume structure, deleting system KEXT caches, and deleting font caches.
Which items aren’t loaded when OS X Safe Boots?
When performing a Safe Boot, OS X doesn’t load third-party KEXTs, third-party launch agents, third-party launch daemons, third-party startup items, third-party fonts, any user login items, or any user-specific launch agents.
How do you further resolve an issue that disappears when the Mac successfully safe-boots?
If an issue disappears when a Safe Boot is successful, you must find and remove the third-party startup resource that caused the issue. The best way to isolate the problem is to start up the Mac in Verbose mode and then observe where the startup process fails. Verbose mode is initiated by holding down Command-V during system startup.
