Exercise 4.3 Create a Full OS X Recovery Disk
In this exercise, you will create a “Full” OS X Recovery disk, which not only includes the OS X Recovery environment and tools, but also a full set of installation assets. With a disk created by this method, you can reinstall OS X Mountain Lion without needing to redownload the installer application from the Internet.
Acquire a Copy of the Install OS X Mountain Lion Application
If you upgraded to OS X Mountain Lion following the instructions in Exercise 2.2 and saved a copy of the installer application, you may use it and skip this section. If you are performing these exercises as part of a class, the instructor may have provided a copy in the StudentMaterials folder. Otherwise, if you have already purchased OS X Mountain Lion from the Mac App Store you can redownload the installer with the following procedure:
- From the Apple menu, choose App Store. Note that the Mac App Store is discussed in more detail in Lesson 19, “Application Installation.”
- From the menu bar, choose Store > Sign In.
Enter the Apple ID and password you used to purchase OS X Mountain Lion. Click Sign In.
Hold the Option key as you click the Purchases icon in the toolbar.
Holding the Option key makes OS X Mountain Lion appear in your purchases list with a Download button, even though you have already installed it.
- Click the Download button for OS X Mountain Lion and wait for it to download.
Reformat the External Disk
Follow the instructions in the “Reformat the External Disk” section of Exercise 4.2, but do not quit Disk Utility at the end.
Create a Full OS X Recovery Disk
- In Disk Utility, click the Restore tab near the top right.
Drag the volume from your external disk (generally named Untitled since it was just erased) from the sidebar into the Destination field.
The image you need to use as a source is concealed inside the Install OS X Mountain Lion package, so you will need to use a special trick to find it. Packages are discussed in Lesson 14, “Hidden Items and Shortcuts.”
- Switch to the Finder, and find the installer app, in either the Applications folder or StudentMaterials/Lesson4.
- Control-click the installer app, and choose Show Package Contents from the shortcut menu.
Inside the package, navigate to Contents/SharedSupport.
In the SharedSupport folder, select the file InstallESD.dmg, and drag it into the Source field in the Disk Utility window.
The Disk Utility window now shows InstallESD.dmg in the Source field and Untitled in the Destination field.
- Click the Restore button near the bottom right of the window.
- In the confirmation dialog, click Erase.
When you are prompted, authenticate as Local Admin (password: ladminpw, or whatever you chose when you created the account).
It will take anywhere from a few minutes to a half hour to copy the full installer to the external disk.
- When the copy is complete, quit Disk Utility.
- If you like, you can use the Finder to change the disk’s name from “Mac OS X Install ESD” to something more descriptive. Adding the specific version number is a good idea.
Test the OS X Recovery Disk
Follow the instructions in the “Test the OS X Recovery Disk” section of Exercise 4.2, but note that the disk will be named either “Mac OS X Install ESD” or whatever you renamed it to in the previous section.