Se è possibile avviare normalmente in OS X, quindi creare un programma di installazione USB OS X. Vedi, Crea un programma di installazione avviabile per OS X (citato sotto) o se non vedi, Come reinstallare OS X .
Use the 'createinstallmedia' command in Terminal
Download the OS X installer from the Mac App Store. Quit the installer if it opens automatically after downloading. The installer
will be in your Applications folder.
Mount your USB flash drive or other volume. You could also use a secondary internal partition.
Open the Terminal app, which is in the Utilities folder of your Applications folder.
Use the createinstallmedia command in Terminal to create the bootable installer. Examples of this command are in the next section.
For detailed usage instructions, make sure that the appropriate
Install OS X app is in your Applications folder, then enter one of the
following paths in Terminal:
Path for El Capitan:
/Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia
Path for Yosemite:
/Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia
Path for Mavericks:
/Applications/Install\ OS\ X\ Mavericks.app/Contents/Resources/createinstallmedia
Examples
This is the basic syntax of the command. Replace volumepath with the
path to your USB flash drive or other volume, and replace
installerpath with the path to the Install OS X app.
createinstallmedia --volume volumepath --applicationpath installerpath
The following examples assume that the OS X installer is in your
Applications folder and the name of your USB flash drive or other
volume is MyVolume:
Example for El Capitan:
sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia --volume
/Volumes/MyVolume --applicationpath /Applications/Install\ OS\ X\ El\
Capitan.app
Example for Yosemite:
sudo /Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia --volume
/Volumes/MyVolume --applicationpath /Applications/Install\ OS\ X\
Yosemite.app
Example for Mavericks:
sudo /Applications/Install\ OS\ X\ Mavericks.app/Contents/Resources/createinstallmedia --volume
/Volumes/MyVolume --applicationpath /Applications/Install\ OS\ X\
Mavericks.app