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.
Download macOS
Dec 25, 2007 I'd like to create a bootable Leopard DVD from which I can run third-party disk-repair applications. For example, can I create an image of the Tech Tool Pro CD, update its system to Leopard and burn a DVD from that image? Create a bootable Leopard DVD.
How to Create Bootable USB for Mac on Windows 10 with 4 Ways? The methods which I am using are, How to Create Bootable USB for Mac with TransMac? How to Create Bootable USB for Mac with Win32 DiskImager and Step by step guide to create Bootable USB with Unibeast and Finally How to Create Bootable USB with DiskMaker X 6. To create a bootable hard drive or flash drive. In Disk Utility, select InstallESD.dmg in the sidebar, and then click the Open button in the toolbar. This mounts the disk image’s volume in the. Sep 23, 2019 A copy of Apple’s macOS (DMG file). Now that you have all the necessary ingredients, you’re ready to make a Mac OS X bootable USB using the DMG file of the operating system with the steps below. How to create Mac OS X bootable USB installation media.
Find the appropriate download link in the upgrade instructions for each macOS version:
macOS Catalina, macOS Mojave, and macOS High Sierra 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. To get the required 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.
macOS Sierra downloads as a disk image that contains a file named InstallOS.pkg. Open this file and follow the onscreen instructions. It installs an app named Install macOS Sierra into your Applications folder.
OS X El Capitan downloads as a disk image that contains a file named InstallMacOSX.pkg. Open this file and follow the onscreen instructions. It installs an app named Install OS X El Capitan into your Applications folder.
Create Boot Disk From .dmg File
Use the 'createinstallmedia' command in Terminal
Connect the USB flash drive or other volume that you're using for the bootable installer. Make sure that it has at least 12GB of available storage and is formatted as Mac OS Extended.
Open Terminal, which is in the Utilities folder of your Applications folder.
Type or paste one of the following commands in Terminal. These assume that the installer is still in your Applications folder, and MyVolume is the name of the USB flash drive or other volume you're using. If it has a different name, replace MyVolume in these commands with the name of your volume. Catalina:* Mojave:*
High Sierra:* Sierra: El Capitan:
Press Return after typing the command.
When prompted, type your administrator password and press Return again. Terminal doesn't show any characters as you type your password.
When prompted, type Y to confirm that you want to erase the volume, then press Return. Terminal shows the progress as the bootable installer is created.
When Terminal says that it's done, the volume will have the same name as the installer you downloaded, such as Install macOS Catalina. You can now quit Terminal and eject the volume.
* If your Mac is using macOS Sierra or earlier, include the --applicationpath argument, similar to the way this argument is used in the commands for Sierra and El Capitan.
Use the bootable installer
After creating the bootable installer, follow these steps to use it:
Plug the bootable installer into a compatible Mac.
Use Startup Manager or Startup Disk preferences to select the bootable installer as the startup disk, then start up from it. Your Mac will start up to macOS Recovery. Learn about selecting a startup disk, including what to do if your Mac doesn't start up from it.
Choose your language, if prompted.
A bootable installer doesn't download macOS from the Internet, but it does require the Internet to get information specific to your Mac model, such as firmware updates. If you need to connect to a Wi-Fi network, use the Wi-Fi menu in the menu bar.
Select Install macOS (or Install OS X) from the Utilities window, then click Continue and follow the onscreen instructions.
Learn more
Create Boot Disk From Dmg
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: