Lesson 28: Troubleshoot Startup and System Issues Flashcards
• Describe the macOS startup process. • Examine the essential files and processes that are required to successfully start up. • Learn about macOS startup modes. • Troubleshoot startup and login processes.
What is the role of the T2 chip in a macOS Mojave startup?
The T2 Chip verifies every step of the boot process to ensure that the hardware and software haven’t been tampered with.
What happens if your macOS computer with a T2 chip identifies errors and experiences failures during the secure startup process?
If your macOS computer with a T2 chip identifies errors and experiences failures during the secure startup, then your Mac will enter macOS Recovery, Apple T2 Security Chip recovery mode, or Apple T2 chip Device Firmware Upgrade mode.
What are the primary system initialization stages in macOS Mojave?
What visual and audible cues do these stages provide?
Each primary stage of system startup can be indicated by the following cues:
- Firmware: Power on. Power-on Self-test (POST). Startup Chime (depending on model).
- Booter: The booter process starts. The Apple logo appears in the center of the main display.
- Kernel: Kernel startup. The progress bar appears.
- System launchd: Starting other items. The Apple logo is replaced with the login window.
What does the firmware do?
What’s the Power-On Self-Test (POST)?
The firmware initializes the Mac computer’s hardware and locates the startup file on a system volume.
The POST checks for basic hardware functionality when a Mac powers on.
What role does launchd serve during Mac startup?
launchd starts macOS Mojave processes.
It also manages macOS Mojave initialization and starts the loginwindow process.
Which items are automatically started by launchd during Mac startup?
During macOS Mojave startup, launchd starts these daemons and scripts:
/System/Library/LaunchDaemons/Library/LaunchDaemons
What are the primary user session stages in macOS Mojave?
What visual and audible cues do these stages provide?
Each primary stage of a user session can be indicated by the following signs:
- The login screen appears
-
launchdloads apps, such as the Finder, after user authentication - The user environment is active any time a user logs in to macOS Mojave
What’s the difference between launch daemons, startup items, launch agents, and login items?
The administrator account launchd process launches launch daemons and startup items during Mac startup.
User account launchd processes launch agents and login items during user environment startups.
What are Safe Sleep, Standby, and Power Nap?
Safe Sleep and Standby are modes used by Mac computers that use very little or no power to safeguard data.
When Mac computers go to sleep, they copy the entire contents of system memory to an image file on the system volume.
This way, if your Mac stays in sleep mode long enough to completely drain the battery, no data is lost when your Mac has to turn off.
- Safe Sleep: Your Mac enters this mode if the battery becomes completely drained or if you leave your Mac idle for a long time.
To wake your computer, restart your Mac just like it was shut down. All Mac models compatible with macOS Mojave support this mode.
* Standby: Your Mac enters this mode as a power-saving standby when it is asleep and completely idle for more than 1 hour, or after 3 hours, depending on the manufacture date.
To wake your Mac, interact with the keyboard, trackpad or mouse; you don’t need to restart your computer.
This mode is used by newer Mac computers with flash storage.
* Power Nap is a state that periodically runs updates while your computer is sleeping.
Information is periodically updated on your Mac while is sleeping.
The type of information that is updated varies, depending on whether your Mac is running on battery power or plugged into a power adapter.
Power Nap enablement varies by type of computer.
What happens during user logout?
During user logout, the user’s loginwindow process performs these actions:
- Requests that user apps quit
- Automatically quits user background processes
- Runs logout scripts
- Records the logout to the main system.log file
- Resets device permissions and preferences to their defaults
- Quits the user’s
loginwindowandlaunchdprocesses
What happens during Mac shutdown?
When a Mac shuts down, loginwindow logs users out and then tells the kernel to quit the remaining macOS Mojave processes.
Then the Mac shuts down.
Which keyboard shortcut is used to start up in safe mode?
Hold down the <kbd>Shift</kbd> key during startup to initiate safe mode.
Which keyboard shortcut can you temporarily use to choose another startup disk?
Hold down the <kbd>Option</kbd> key during startup to open Startup Manager.
This enables you to temporarily choose another startup disk.
What changes are made when macOS Mojave starts up in Safe Mode?
Startup in Safe Mode performs the following permanent actions:
- Attempts to repair the system volume structure
- Deletes system third-party kernel extension (KEXT) caches
- Deletes font caches
Which items aren’t loaded when macOS Mojave starts up in Safe Mode?
When macOS Mojave performs a startup in Safe Mode, it doesn’t load:
- KEXTs
- Third-party launch agents
- Third-party launch daemons
- Third-party startup items
- Third-party fonts
- User login items
- User-specific launch agents
