OS X Support Essentials 10.8 - Training - Apple

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OS X Support Essentials 10.8 Exam Preparation Guide 1. What are the primary system initialization stages in OS X? What are the visual and audible cues of these items? 2. What does the firmware do? What is the Power-On Self-Test (POST)? 3. What role does the system launchd process serve during system startup? 4. Which items are automatically started by the system launchd during the system initialization process? 5. What are the primary user session stages in OS X? What are the visual cues of these items? 6. What is the difference between launch daemons, startup items, launch agents, and login items? 7. What are Safe Sleep and Power Nap? 8. What happens during user logout? 9. What happens during system shutdown? Answers 1. 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. 2. 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. 3. The system launchd process is ultimately responsible for starting every system process. It also manages system initialization and starts the loginwindow process. 4. 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. 5. 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. 48
OS X Support Essentials 10.8 Exam Preparation Guide 6. 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. 7. 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. 8. 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. 9. 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. Lesson Thirty review questions After completing Lesson Thirty, you should be able to answer the following questions. 1. Which keyboard shortcut is used to Safe Boot OS X? 2. Which keyboard shortcut can be used to temporarily choose another startup disk? 3. Which changes are made when performing a Safe Boot? 4. Which items aren’t loaded when performing a Safe Boot? 5. How do you further resolve an issue that disappears when a Safe Boot is successful? Answers 1. A Safe Boot is initiated by holding down the Shift key during system startup. 2. Holding down the Option key at startup opens Startup Manager, which allows you to temporarily choose another startup disk. 3. A Safe Boot performs the following permanent actions: attempting to repair the system volume structure, deleting system KEXT caches, and deleting font caches. 49
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