OS X: About OS X Recovery

OS X Lion and later include OS X Recovery. This feature includes all of the tools you need to reinstall OS X, repair your disk, and even restore from a Time Machine backup.

About Recovery

   

Recovery System

OS X Recovery includes a built in set of utilities as part of the Recovery System. You can use OS X Recovery to do the following:

• Restore your Mac from a Time Machine backup.
• Verify and repair connected drives using Disk Utility.
• Check your Internet connection or get help online using Safari.
• Install or reinstall OS X.

To start your computer from Recovery, restart your Mac and hold down the Command and R keys at startup.

Hold these keys until the Apple logo appears. After your computer finishes starting up, you should see a desktop with an OS X menu bar and an OS X Utilities window with the options listed above. If you see a login window or your own desktop instead of the Utilities window, it's possible that you didn't press Command-R early enough. Restart your computer and try again.

Choose the option you want to use from the Utilities window or the Utilities menu.

In order to reinstall OS X, you need to be connected to the Internet using Ethernet or Wi-Fi. If you're using a wireless Internet connection, click the Wi-Fi menu in the upper-right corner of the screen to select a nearby Wi-Fi network. Choose your preferred network name and enter a username and password to join the network if needed.

OS X Internet Recovery

Newer Macs include the ability to start up directly from an Internet-based version OS X Recovery. Your Mac automatically uses this feature when the Recovery System on the startup drive isn't available. For example, if your startup drive encounters an issue, or if your startup drive has been replaced or erased. Internet Recovery lets you start your Mac directly from Apple's servers. Starting up from this system performs a quick test of your memory and hard drive to check for hardware issues.

Internet Recovery initially asks you to select a Wi-Fi network and enter a network password when needed. Next, Internet Recovery downloads and starts from a Recovery System image. From there, you are offered the same utilities and options as the Recovery System on a startup drive.

Some Macs that came with OS X Snow Leopard can use Internet Recovery after installing OS X Lion or later and a software update.

Requirements for reinstalling OS X using Recovery

Reinstalling OS X using Recovery requires broadband access to the Internet using a Wi-Fi or Ethernet connection. OS X is downloaded over the Internet from Apple when OS X Recovery is used for reinstallation. You must use DHCP on your Wi-Fi or Ethernet network to reinstall OS X using OS X Recovery.

If you bought OS X from the Mac App Store, you may be prompted to enter the Apple ID and password you used to purchase OS X.

The time required to download OS X varies, depending on the speed of your Internet connection and the version of OS X you are installing. If your Internet connection has requirements or settings that are not supported by OS X Recovery, change the settings to a supported configuration for the duration of your OS X reinstall, or look for another place where you're permitted to access the Internet (like the home of a friend or family member, or possibly your place of employment with appropriate permission).

Supported network configurations and protocols

	local Recovery System	Internet Recovery
WEP	Yes	No
WPA/WPA2	Yes	Yes
WPA-Enterprise	Yes	No
PPPoE (where there is no router handling the PPPoE connection)	No	No
Captive-Networks (where you click an "Agree" button to access the Internet)	Yes	No
Proxies (where specific proxy servers must be configured in network preferences)	No	No
Certificate-based authentication / 802.1x	No	No

Which version of OS X is installed by OS X Recovery?

• If you use the Recovery System stored on your startup drive to reinstall OS X, it installs the most recent version of OS X previously installed on this computer.
• If you use Internet Recovery to reinstall OS X, it installs the version of OS X that originally came with your computer. After installation is finished, use the Mac App Store to install related updates or later versions of OS X that you have previously purchased.

Additional Information

Some drive partition configurations can result in the OS X Installer reporting that it cannot create a Recovery System. If this happens, you might want to quit the installation and create an external OS X hard drive with a Recovery System first. You can continue installing OS X on your computer's startup drive after creating an external Recovery System.

OS X Recovery must be present on the computer's startup drive in order to use FileVault full disk encryption. Using RAID partitions or non-standard Boot Camp partitions on the startup drive might prevent OS X from installing a local Recovery system. See "OS X: Some features of Mac OS X are not supported for the disk (volume name)" for more information.

OS X Recovery includes a version of Safari with links to resources at Apple's support website that you can use to get additional help. The network requirements listed above also apply to the version of Safari included with OS X Recovery. Plugins and Safari Extensions cannot be added to the version of Safari included with OS X Recovery.

https://support.apple.com/en-ap/HT201314