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.
May 04, 2020 The above instructions can only be carried out on a mac that can run El Capitan, any mac that came preinstalled with. An OS newer than El Capitan will not be able to do this. The alternative would be to try and re install El Capitan from Apples Recovery Servers, have you tried that, Restart your mac, press and hold the Command and R keys. The above instructions can only be carried out on a mac that can run El Capitan, any mac that came preinstalled with. An OS newer than El Capitan will not be able to do this. The alternative would be to try and re install El Capitan from Apples Recovery Servers, have you tried that, Restart your mac, press and hold the Command and R keys.
What you need to create a bootable installer
- A USB flash drive or other secondary volume formatted as Mac OS Extended, with at least 14 GB of available storage
- A downloaded installer for macOS Big Sur, Catalina, Mojave, High Sierra or El Capitan
Download macOS
- Download: macOS Big Sur, macOS Catalina, macOS Mojave or macOS High Sierra
These will be downloaded to your Applications folder as an app named Install macOS [version name]. If the installer opens after downloading, quit it without continuing installation. 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. - Download: OS X El Capitan
This will be downloaded as a disk image named InstallMacOSX.dmg. On a Mac that is compatible with El Capitan, open the disk image and run the installer within, named InstallMacOSX.pkg. It will install 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.
Use the 'createinstallmedia' command in Terminal
- Connect the USB flash drive or other volume that you're using for the bootable installer.
- 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 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.
Big Sur:*
Catalina:*
Mojave:*
High Sierra:*
El Capitan:
* If your Mac is using macOS Sierra or earlier, include the --applicationpath
argument and installer path, similar to the way this is done in the command for El Capitan.
After typing the command:
- Press Return to enter 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 volume is erased. - After the volume has been erased, you may see an alert stating that Terminal would like to access files on a removable volume. Click OK to allow the copy to proceed.
- When Terminal says that it's been completed, the volume will have the same name as the installer you downloaded, such as Install macOS Big Sur. You can now quit Terminal and eject the volume.
Use the bootable installer
Determine whether you're using a Mac with Apple silicon, then follow the appropriate steps:
Apple silicon
- Plug the bootable installer into a Mac that is connected to the internet and compatible with the version of macOS you're installing.
- Turn on your Mac and continue to hold the power button until you see the startup options window, which shows your bootable volumes.
- Select the volume containing the bootable installer, then click Continue.
- When the macOS installer opens, follow the onscreen instructions.
Intel processor
- Plug the bootable installer into a Mac that is connected to the internet and compatible with the version of macOS you're installing.
- Press and hold the Option (Alt) ⌥ key immediately after turning on or restarting your Mac.
- Release the Option key when you see a dark screen showing your bootable volumes.
- Select the volume containing the bootable installer. Then click the up arrow or press Return.
If you can't start up from the bootable installer, make sure the External Boot setting in Startup Security Utility is set to allow booting from external media. - Choose your language, if prompted.
- Select Install macOS (or Install OS X) from the Utilities window, then click Continue and follow the onscreen instructions.
Learn more
A bootable installer doesn't download macOS from the internet, but it does require an internet connection to get firmware and other information specific to the Mac model.
For information about the createinstallmedia
command and the arguments you can use with it, make sure the macOS installer is in your Applications folder, then enter the appropriate path in Terminal:
The new OS X El Capitan features a new Split View, features in Safari, Mail, Notes, Maps, and Photos, and more. To get your hands on all this new stuff, you have to install the operating system on your Mac.
If you want to perform a typical OS upgrade, it’s easy. You download it through the App Store. Here, we’ll go through the steps of installing EL Capitan from Yosemite.
It’s about preparation
Before you install the upgrade, there’s a little bit of prep work you should do. Our article on how to get your Mac ready for OS X 10.11 El Capitan is what you should read before you proceed. It covers:
- Compatible hardware and older versions of OS X
- Verifying the health of your Mac
- Installing updates
- Backups
- Encryption issues
Go read that article and come back here when you’re ready to go.
How To Install El Capitan
How to download El Capitan
Apple provides the El Capitan upgrade through its App Store. The download is a bit over 6GB, so you may want to download it at a time when you have other things to do—how long the download takes depends on your Internet connection and the amount of activity at the App Store. Or you can use your Mac while you wait, but be ready to save your work and quit when the download is done.
To download El Capitan, launch the App Store app in your Applications folder (or go to Apple menu > App Store). You’ll probably find El Capitan right away, especially if go to the App Store soon after the official release. Apple will probably have a banner at the top promoting El Capitan, but if you don’t see one, you can probably find it in the Free section in the far right column (you might have to scroll down to see it). And you can always do a search on El Capitan.
When you get to the El Capitan page in the App Store, click on the Download button. You may have to enter your Apple ID name and password, and after you do, the installer will download.
Copy the installer
When the download finishes, the installer automatically launches. Don’t click Continue in the installer just yet. What you may not know is that the installer is downloaded to your Applications folder and then deleted after the installation is done.
If you ever need the installer again, you can get it in the App Store. But I like to make a copy of the installer. I often have to perform OS installations, so I make a bootable flash drive that I can use; it’s a lot faster than waiting for the download.
To copy the installer, you need to hold down the Option key as you drag the Install OS X El Capitan app in your Applications folder to the copy destination. If you don’t hold down Option, you’ll create an alias, not a copy.
Install El Capitan
Install El Capitan On Macbook Pro
OK, now you can click that Continue button in the installer window. (If the installer isn’t running, go to your Applications folder and double click the Install OS X El Capitan app.) You’ll be asked to agree and then confirm that you agree to the license agreement.
The next screen will ask you to select the disk for the El Capitan installation. If you have one storage device with one partition, you’ll see it in the installer window. But if you have multiple storage devices and/or multiple partitions, you can select the one you want by clicking the Show All Disks button. Make your selection and click Install.
To continue, you must enter your username and password. The install will prepare to install, restart your Mac, and perform the installation. The Mac may restart again during the installation process. The install will take several minutes, so you may want to go for a walk, call your mom, take a nap, or catch up on chores while the software does its thing.
When the installation is finished, the Mac will restart and you’ll need to log in with your username and password. You may be asked if you want to send diagnostic data to Apple and that you need to log in with your Apple ID, and then a setting up screen will appear and go away. You’re done.
Want to do a clean install of El Capitan?
A clean installation is when you install the operating system on a blank storage device. You can do this by creating a bootable El Capitan installer, and then use it as the boot drive for your Mac. You run Disk Utility to erase your drive and then proceed with the El Capitan installation.
Once the installation is done, you use Migration Assistant to transfer your data from a Time Machine backup.
Why should you do a clean install? Maybe you partitioned your storage device and want to change the scheme. Or maybe you’ve installed and removed lots of apps over time and want to get right of any lingering software components—if this is the case, don’t restore your data from a Time Machine backup. Manually copy your files and reinstall your software.