Many Mac users like to make a bootable installer drive for installing OS X El Capitan, whether for performing a clean install, or for making it easier to install OS X 10.11 onto multiple Macs. We will walk through creating a bootable install flash drive from OS X El Capitan with the final public.
With the release of OS X 10.7 Lion in 2011, Apple officially for its operating system installations. Instead of a traditional disc, customers could now purchase and download OS X directly from the. This approach brought many benefits, such as not having to keep and safeguard a physical disc, immediate access to the OS when purchased instead of having to wait in line, and server-side updates to the downloadable installer so that the most current version of OS X is always installed when updating new machines. But what if you’ve just installed a new hard drive in your Mac and have no version of OS X with the Mac App Store?
Or what if you don’t have a reliable Internet connection? In these cases, it’s always best to have a physical local copy of the OS X installer.
Here’s how to create your own USB or DVD Installer for OS X. First, you’ll have to purchase a copy of OS X from the if you don’t already have one. Note that you can always re-download the version of OS X that came with your Mac for free. As of the date of this article, OS X 10.8 Mountain Lion is the current OS, although the OS X 10.9 Mavericks is right around the corner. If you’ve already purchased OS X, open the Mac App Store and head over to the “Purchases” tab. Find your desired version of OS X in the list and click the “Download” button to the right.
OS X is a multi-gigabyte file so the download process may take a while depending on your connection speed. Once it’s complete, the OS X Installer will automatically launch. Quit it by pressing Command+Q; we don’t need the installer application, just what’s inside it. Open Finder and navigate to your Applications folder. Here you’ll find an app called “Install OS X 10.8 Mountain Lion” or something similar depending on the version of OS X you downloaded from the Mac App Store. Right-click (or control-click) on this file and select “Show Package Contents.” This will reveal the “guts” of the Installer’s application package.
Drill down to Contents SharedSupport and find the “InstallESD.dmg” file. This is the disk image we’ll need to create a local OS X installation disc or USB drive. Copy it from the installer package to your Desktop. Now you’ll need to decide what you’d like to use for your installation media. A USB drive is fast and durable, but you can also burn the image to a bootable dual-layer DVD. An external hard drive is also an option, although you’d want to specifically for the OS X Installer so as not to waste the entire drive’s capacity.
For our example, we’ll use a USB drive. Create an OS X USB Installer Mount your drive or disc of choice to your Mac and launch Disk Utility. Find your target drive in the list on the left and select the “Restore” tab on the right. You’ll see two fields: Source and Destination. Drag the InstallESD image from your Desktop and drop it over the Source box, then drag the USB drive from the list in Disk Utility and drop it on the Destination box. This is telling Disk Utility that we want to take the contents of the OS X Installer image and copy it exactly to our USB drive. Press Restore to start the process.
Disk Utility will warn you that this process will delete the contents of your USB drive and ask you for confirmation. Disk Utility will then ask for an administrator password. Enter it and then sit back and wait for the restore to complete.
Create an OS X Install DVD To create an Install DVD, insert a blank dual-layer DVD and open Disk Utility. Choose “Images” from the Menu Bar, and then “Burn.” Disk Utility will ask you which image you’d like to burn. Navigate to your Desktop and choose the InstallESD file you copied earlier, then click “Burn” to start the process. Once either step is complete, you’ll have a bootable OS X Installer that you can use to quickly upgrade your Macs in the future without having to download the installer from the Mac App Store. To use it, insert your disc or attach your USB drive to your Mac. Then reboot the Mac while holding down the Alt/Option key on your keyboard.
Keep holding the key until the Mac boot manager launches and shows you the available boot disks. Choose your DVD or USB installer and press Return.
The OS X installer will now launch and you will have the option of performing restore operations or wiping the Mac’s drive and installing a fresh copy of OS X.
Apple uses its App Store to distribute its software, like new Mac operating systems. It’s convenient, but sometimes it can take a while for a download to finish. And if you have multiple Macs, it’s inefficient to download the new OS to each and every Mac. That’s why I like to make a bootable external drive for the sole purpose of installing the Mac operating system. When I need to tend to a bunch of Macs, it’s much faster to use a bootable drive instead of going to each Mac, launching the App Store, searching for the operating system, downloading it (after entering my Apple ID), and then running the installer.
You can create a bootable USB flash drive with the macOS Sierra installer that’s now available. The installer software will take up nearly 5GB of storage space. Here’s how to create a bootable macOS Sierra installer drive. Macworld also has bootable-install-drive instructions for:. Download the macOS Sierra installer Launch the App Store app, then look for macOS Sierra in the store.
(.) Click on the Download button, and your Mac will download the installer to your Applications folder. If it automatically launches after download, quit the installer. Keep the installer in the Applications folder. If you’ve already upgraded your Mac to Sierra, the installer is removed from the Applications folder. You can download it again if you go to Purchased in the App Store. Look for macOS Sierra in the list of apps that you’ve bought, and click on the Download button. If it automatically launches after download, quit the installer.
Get an external drive You can use a USB flash drive or a hard drive with room for the installer software. I’ve used different drives with success, including a VisionTek 120GB USB 3.0 Pocket Solid State Drive ($83 on ) and an old 8GB Iomega Micro Mini Hard Drive. Don’t worry if the drive isn’t formatted for the Mac. The drive will be reformatted automatically as part of the process. Change the name of your drive to Untitled; you need to do this for the steps below. The quick and easy way The process detailed below involves the Terminal. If your really don’t want to use Terminal, there are a couple of free apps you can use.
is a straightforward way to create a boot disk. I was able to make a macOS Sierra external USB boot disk in a few minutes, and the installation worked without a hitch. Also works with older versions of OS X. is a popular app.
It also supports older versions of OS X. Use the Terminal to create a boot disk So you have your external drive, and the Sierra beta installer is in place.
Now you’re going to use Terminal to create a boot drive. If you’ve never used Terminal before, don’t worry. This is pretty easy. Here are the steps to create a macOS Sierra beta boot disk. (.). Connect the external drive to your Mac.
(In the Terminal command you will use, I use Untitled to represent your external drive. If your drive is named something else, you need to change Untitled to the name of your drive.). Launch Terminal (/Applications/Utilities/Terminal.app). Copy the following: sudo /Applications/Install macOS Sierra.app/Contents/Resources/createinstallmedia -volume /Volumes/Untitled -applicationpath /Applications/Install macOS Sierra.app. Go back to Terminal and paste the copied code at the prompt. Terminal will ask for a password. This is your user password.
Terminal doesn’t display characters when you type it in. Terminal will tell you that it will erase your drive.
To confirm that you want to continue, type Y and hit Return. You’ll see that Terminal erases your drive. When that part is done, your Mac may ask you if you want to use the drive for Time Machine.
Click Don’t Use. Terminal will copy the installer file to your drive. This will take a few minutes. After copying, Terminal is done.
You should see Terminal display a “Copy complete” and Done notice. You can quit Terminal and your drive is ready for use. How to boot from the installer drive.
Plug your external drive into your Mac. Power up (or restart) your Mac. Press down on the Option key while the Mac boots.
After a few moments, your Mac should display the Startup Manager, which will show you the available boot drives. Click on the external drive and hit Return. (You don’t need to select a network to proceed.). Your Mac will display an OS X Utilites window. If you want to install Sierra and leave the data intact, select Install OS X. If you want to start over and wipe out the data, you need to go into Disk Utility to reformat the internal drive first, and then install macOS Sierra.