These advanced steps are primarily for system administrators and others who are familiar with the command line. You don't need a bootable installer to upgrade macOS or reinstall macOS, but it can be useful when you want to install on multiple computers without downloading the installer each time.
Mac mini introduced in early 2009 or later iMac introduced in mid 2007 or later Mac Pro introduced in early 2008 or later Xserve models introduced in early 2009. To find your Mac model, memory, storage space, and macOS version, choose About This Mac from the Apple menu. If your Mac isn't compatible with OS X Yosemite, the installer will let. Download the Yosemite installer from the Mac App Store and make sure it’s in your main Applications folder (/Applications)—it’s called Install OS X Yosemite.app. Connect to your Mac a. Nov 29, 2017 The following method allows you to download Mac OS X Lion, Mountain Lion, and Mavericks. Start your Mac holding down Command + R. Prepare a clean external drive (at least 10 GB of storage). Within OS X Utilities, choose Reinstall OS X.
Find the appropriate download link in the upgrade instructions for each macOS version:
macOS Catalina, macOS Mojave, ormacOS High Sierra
Installers for each of these macOS versions download directly to your Applications folder as an app named Install macOS Catalina, Install macOS Mojave, or Install macOS High Sierra. If the installer opens after downloading, quit it without continuing installation. Important: To get the correct installer, download from a Mac that is using macOS Sierra 10.12.5 or later, or El Capitan 10.11.6. Enterprise administrators, please download from Apple, not a locally hosted software-update server.
OS X El Capitan
El Capitan downloads as a disk image. On a Mac that is compatible with El Capitan, open the disk image and run the installer within, named InstallMacOSX.pkg. It installs an app named Install OS X El Capitan into your Applications folder. You will create the bootable installer from this app, not from the disk image or .pkg installer.
MyVolumein these commands with the name of your volume.
Yto confirm that you want to erase the volume, then press Return. Terminal shows the progress as the bootable installer is created.
* If your Mac is using macOS Sierra or earlier, include the
--applicationpath argument, similar to the way this argument is used in the command for El Capitan.
After creating the bootable installer, follow these steps to use it:
For more information about the
createinstallmedia command and the arguments that you can use with it, make sure that the macOS installer is in your Applications folder, then enter this path in Terminal:
Mac OS X Yosemiteis the eighth major release of Mac OS X (now named macOS), Apple's desktop and server operating system for Macintosh computers.
OS X Yosemite Requirements