Exercise 4.1 Use OS X Recovery
In this exercise you will start up your computer in OS X Recovery. OS X Recovery is stored on a hidden partition named Recovery HD that is created automatically when OS X is installed on the hard disk. You will review the included utilities as well as how OS X Recovery can reinstall the system itself.
Start Up Using OS X Recovery
To access the Installer and other utilities in OS X Recovery, you need to start up from the hidden Recovery HD partition.
- If your computer is on, shut it down by choosing Apple menu > Shut Down.
Press the power button on your computer, and then hold down Command-R until the gray Apple appears on the screen.
When you hold down Command-R during startup, the computer attempts to start up using a recovery partition on the hard disk.
If no recovery partition is available, Macs with newer firmware can actually start up from an Apple server over the Internet and get access to the OS X Recovery features.
If your computer starts up to the login screen instead of OS X Recovery, you may not have held Command-R long enough. If this happens, click the Shut Down button and try again.
If your computer displays a globe icon with the text “Starting Internet Recovery. This may take a while,” your computer was unable to find a local Recovery partition. If the Recovery partition exists, you can shut down your computer by holding the power button for 10 seconds, and then select the Recovery partition using the Startup Manager (see the instructions in Exercise 4.2, in the “Test the OS X Recovery Disk” section). If your computer does not have a Recovery partition, you can let it finish starting into Internet Recovery, and then proceed with this exercise.
- If a language selection screen appears, select your preferred language and click the right-arrow button.
After OS X Recovery starts up, you will see a Mac OS X Utilities window. This window is the primary interface for OS X Recovery.
If you see a Welcome screen instead, you probably pressed Command-R too late or did not hold it down long enough. You can start over by pressing Command-Q, and then clicking the Shut Down button.
Examine the Utilities Available in OS X Recovery
While running OS X Recovery, you have access to some utilities for recovering, repairing, and reinstalling OS X. In this part of the exercise you will look at some of these utilities in order to become more familiar with them.
View Help for OS X Recovery
You will use Safari to view the built-in instructions of OS X Recovery and to browse the web.
Select Get Help Online, and then click Continue.
Safari opens and displays a document with information about how to use OS X Recovery. Take a moment to skim the document.
This document is stored on the Recovery HD partition, but as long as you have an Internet connection available, you can also use Safari to view online documentation such as the Apple Knowledge Base.
Click the Apple bookmark.
Safari now displays the Apple website.
- If Safari displays a message that “You are not connected to the Internet,” you can join a wireless network using the Wi-Fi icon near the right side of the menu bar.
- If you are prompted to unlock the Login keychain, click OK.
Click the Support link near the top right of the page.
You are taken to the support section of the Apple site. If you were experiencing a problem with your computer, this would be a good place to look for solutions and information. You will use some of the Apple support resources later in this guide.
From the menu bar, choose Safari > Quit Safari to return to the main utilities screen.
Note that closing the Safari window does not actually quit Safari. This is common among Mac applications, but if you are accustomed to using Microsoft Windows it may be contrary to your expectations. Generally, the best way to quit a Mac application is to choose Quit <Application Name> from the application menu (the menu next to the Apple menu, named for the current application); you can use the keyboard shortcut Command-Q.
Examine Disk Utility
Disk Utility is provided in OS X Recovery to allow you to repair, image, reformat, or repartition your computer’s disk.
Select Disk Utility, and then click Continue.
In the Device List on the left, you will see your disk device and Mac OS X Base System disk image. Note the primary entry for each physical disk device and an indented list of volumes on each device (discussed in more detail in Lesson 10, “File Systems and Storage”).
Select the entry that represents your startup volume. It will typically be named Macintosh HD.
Notice the options available to perform on the volume: First Aid, Erase, RAID, and Restore. Among the reasons Disk Utility is provided in OS X Recovery is to allow you to verify or repair the startup volume’s file structure, or if necessary to erase the volume before reinstalling OS X.
Select the entry that represents your disk (just above the startup volume).
Notice that the Partition option is now available.
Quit Disk Utility by choosing Disk Utility > Quit Disk Utility (or by pressing Command-Q).
You are returned to the main screen.
Examine Time Machine Restoration
If you backed up your computer with Time Machine, OS X Recovery has the capability to do a full system restoration from that backup. Setting up Time Machine is covered in Lesson 17, “File Archives.”
Select Restore From Time Machine Backup, and then click Continue.
A page of notes on the restoration process appears. It is important to note that this restoration interface will erase all current data and replace it from the backup; other restoration interfaces that let you control which files or folders are restored are examined later.
The “Select a Backup Source” screen appears. If you had configured a Time Machine backup target, it would be available here as a source for restoring your system.
- Click Go Back to return to the Restore Your System screen.
- Click Go Back again to return to the main screen.
Examine the OS X Installer
Now you will examine the reinstallation process, but you will not perform the installation. By going through the following steps, you can experience the configuration of an installation without actually waiting for the OS X software to be copied to your system.
Select Reinstall OS X, and then click Continue.
The OS X Mountain Lion installer opens.
A dialog appears indicating that this computer’s eligibility will be verified with Apple.
- At the license agreement, click Agree.
In the license confirmation dialog, click Agree again.
The OS X installer displays a list of partitions where you could install or reinstall OS X.
- Quit the Installer.
Verify Your Startup Disk and Restart
The Startup Disk utility allows you to select the volume from which to start up. If you are having problems during system startup from your computer’s internal disk, you could connect a second disk with OS X installed and use Startup Disk to configure the computer to start up from the new disk.
- From the Apple menu, choose Startup Disk. Notice that Startup Disk shows you a list of all startup volumes. One of the options may be Network Startup or one or more NetBoot images, depending on what it finds on your network.
Verify that your computer’s normal startup volume (typically named Macintosh HD) is selected; if necessary, select it.
- Click Restart.
In the confirmation dialog, click Restart.
You could also restart without using the Startup Disk utility by choosing Apple menu > Restart.