Exercise 4.2 Create a Minimal OS X Recovery Disk
The OS X Recovery partition can help you recover from many problems that might otherwise render your computer unusable, but there are a few issues it cannot help with. For instance, anything that renders the computer’s startup disk unreadable, such as a damaged partition table or even complete disk failure, will also prevent the Recovery HD partition from being used. This exercise will explore another option: You can copy OS X Recovery onto an external disk, such as a USB flash disk, for use in case of emergency.
Download the Recovery Disk Assistant
The following steps walk you through searching the Apple support resources for the OS X Recovery Disk Assistant, and downloading it.
Open Safari. Note the shortcut for it in your Dock.
- If you are not automatically taken to the Apple website, click the Apple shortcut in the Safari bookmark bar.
Click the Support link near the top right of the Apple web page.
The support section of the Apple website includes a wide variety of resources, including software downloads, manuals and specifications, the Apple Knowledge Base, and links to warranty and repair information.
In the search field to the right of the Support link (not the search field in the Safari toolbar), enter recovery disk assistant, and press Return.
The search results page has a number of options to change and refine your search, but you should not need these here; one of the first search results should be a download page (indicated by a green down-arrow icon) for OS X Recovery Disk Assistant.
- Click the link for the OS X Recovery Disk Assistant.
Click the Download button.
While it downloads, take a moment to skim the information in the download page. Note that it includes a summary of what the program is and how to use it, as well as its version, system requirements, and a list of supported languages.
- When the download is complete, quit Safari.
Reformat the External Disk
Most external disks come preformatted with the MBR partition scheme; in order to allow an Intel Mac to start up from it, you must reformat this disk with the GUID Partition Table (GPT) partition scheme. Disk formats are discussed in more detail in Lesson 10 “File Systems and Storage.”
- Open Disk Utility. It is located in the Utilities folder, which is inside the Applications folder. You can navigate to this folder in the Finder, use the Finder shortcut Command-Shift-U, or open Launchpad from the Dock and then select the Other icon in Launchpad.
- Plug the external disk into your computer.
- If you are prompted for a password to unlock the disk, the disk is encrypted and cannot be used for this exercise. If this happens, eject the disk and use a different disk for the exercise.
- Select the external disk device entry in the Disk Utility sidebar. Be sure to select the device entry, not the volume entry indented beneath it.
Check the Partition Map Scheme listed at the bottom of the window.
Depending on what this disk was used for most recently, the partition scheme could be anything. In order to convert it to the GPT scheme, you will erase the disk. If it is already using the GPT scheme, this is not strictly necessary, but you should erase it just to be sure.
It is also possible to partition the disk, and use only part of it for OS X Recovery. The download page has a link to more information about OS X Recovery Disk Assistant, including the partitioning procedure.
- Click the Erase tab.
Choose Mac OS Extended (Journaled) from the Format pop-up menu.
- Click the Erase button near the bottom right of the window.
- In the confirmation dialog, click Erase.
Verify that the Partition Map Scheme is now listed as GUID Partition Table.
Since you erased the entire disk, rather than a single volume within the disk, Disk Utility has rebuilt the partition map as well. Although a Mac OS Extended volume can be created under any supported partition scheme, Disk Utility created a GUID Partition Table because it is the best fit.
- Quit Disk Utility.
Create an OS X Recovery Disk
Near the right of the Dock is a shortcut for your Downloads folder. Click it once to show its contents.
Click RecoveryDiskAssistant.dmg to open it.
The disk image opens, and its contents—the Recovery Disk Assistant application—appear.
Open the Utilities folder by choosing Go > Utilities (or press Command-Shift-U).
A new Finder window opens, revealing the contents of the Utilities folder.
- Drag the Recovery Disk Assistant application to the Utilities folder.
A warning dialog appears. Click Authenticate and then enter the password for the Local Admin (ladminpw, or whatever you chose when you created the account).
Once the copy is complete, double-click the Recovery Disk Assistant in the Utilities folder.
Since this application was downloaded from the Internet, a warning dialog opens providing information about where the application came from. Since malware is sometimes distributed via web download, this warning gives you a chance to decide if you can really trust this software before running it. This feature is discussed in more detail in Lesson 19, “Application Installation.” As this application was downloaded directly from the Apple website, you can go ahead and trust it.
- Click Open.
- In the license agreement, click Agree.
Select the icon for your external disk and click Continue.
Authenticate as Local Admin when prompted.
The creation process takes a few minutes.
- When the process completes, click Quit.
Test the OS X Recovery Disk
- From the Apple menu, choose Restart.
- In the confirmation dialog, click Restart.
Hold down the Option key as the computer restarts. Keep holding it until a row of icons appears across the screen.
This is the Startup Manager, which allows you to choose which volume to start up from. You will see your regular startup volume (normally Macintosh HD), and two volumes named Recovery-10.8, one with a disk icon and one with a USB, FireWire, or Thunderbolt icon. Since both your external disk and your computer’s internal disk now have valid, up-to-date Recovery-10.8 volumes, you could access OS X Recovery with either one of them.
- If you have not used OS X Recovery before, you can select the Recovery drive, then click the up-arrow button that appears underneath it. Then, follow the instructions in Exercise 4.1 to explore the features of OS X Recovery.
- If you have already performed Exercise 4.1, you have already experienced OS X Recovery, and you can start up from your normal startup volume instead. Unplug the external disk, select the Macintosh HD icon, and then click the up-arrow button below it.