How to Make a Bootable OS X El Capitan GM / Beta USB Installer Drive
Many Mac users interested in running OS X El Capitan may wish to have a bootable install drive of the new operating system. We’re going to demonstrate how to do this with a USB flash drive, but technically you can create a boot installer out of just about any USB device which has sufficient space. The process of creating the boot installer for OS X 10.11 is easy enough, though users should have some experience and comfort with the command line before attempting to do so.
The basic requirements to make a bootable OS X El Capitan install drive are as follows:
- An 8GB or larger USB Flash Drive, this will be formatted and turn into the OS X El Capitan bootable installer
- The OS X El Capitan installer application, this can be downloaded from Apple (either as Public Beta or Developer Beta, or preferably the GM Candidate)
Naturally, you’ll also need a OS X 10.11 compatible Mac for the destination. Beyond that, we’re going to assume you have an appropriately sized USB drive ready, and the “Install OS X 10.11” application file residing in the /Applications/ folder of OS X, which is where it downloads to by default.
Make an OS X El Capitan GM / Beta Bootable Installer Drive
- Connect the USB drive to the Mac and launch Disk Utility, then select the USB drive from the left side menu and go to the “Erase” tab
- Format the USB flash drive as “Mac OS Extended (Journaled)” and choose Erase to confirm the process – this formats the USB drive which will become the installer, be absolutely certain you have selected the right volume or you will lose data
- Now go to the “Partition” tab and change the partition layout to “1 Partition”, then change the name of the partition to “ElCapInstaller” or another name of your choosing
- Click on “Options” and select “GUID Partition Table”, and click “OK”, followed by “Apply”, then quit out of Disk Utility
- Launch the Terminal application and paste the following string into the command line, if you changed the installer name “ElCapInstaller” to something else, be sure to adjust that in the syntax:
- Hit the Return key and enter the admin password when requested (this is necessary to use sudo), you’ll then see numerous progress indicators as the process completes, it will be finished when the last messages is “Done.”
- When completed, the USB bootable installer will be created and you have an OS X El Capitan installer drive, exit out of Terminal and you’re ready to go
For OS X El Capitan final release: (full tutorial for final version are here)
sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/ElCapInstaller --applicationpath /Applications/Install\ OS\ X\ El\ Capitan.app --nointeraction
For OS X El Capitan GM Candidate:
sudo /Applications/Install\ OS\ X\ El\ Capitan\ GM\ Candidate.app/Contents/Resources/createinstallmedia --volume /Volumes/ElCapInstaller --applicationpath /Applications/Install\ OS\ X\ El\ Capitan\ GM\ Candidate.app --nointeraction
For OS X El Capitan Public Beta:
sudo /Applications/Install\ OS\ X\ El\ Capitan\ Public\ Beta.app/Contents/Resources/createinstallmedia --volume /Volumes/ElCapInstaller --applicationpath /Applications/Install\ OS\ X\ El\ Capitan\ Public\ Beta.app --nointeraction
For OS X 10.11 Developer Beta:
sudo /Applications/Install\ OS\ X\ 10.11\ Developer\ Beta.app/Contents/Resources/createinstallmedia --volume /Volumes/ElCapInstaller --applicationpath /Applications/Install\ OS\ X\ 10.11\ Developer\ Beta.app --nointeraction
“Erasing Disk: 0%… 10%… 20%… 30%…100%…
Copying installer files to disk…
Making disk bootable…
Copying boot files…
You can boot from the drive by holding down the Option key and selecting “Install OS X El Capitan” from the boot volume menu.
If you’re going to install OS X El Capitan beta, you should do so safely on a secondary partition, if not a secondary Mac. Beta system software is often unstable and is not intended for primary use outside of development environments.
By the way, you may notice that drive creation command looks familiar, and that’s because it’s basically the same ‘createinstallmedia’ function that allowed for the creation of an OS X Yosemite boot install drive too,with the primary difference being the application path to the installer file, and of course, the version of OS X itself.
Unless something changes, this command will almost certainly work to make a boot installer with future versions of the OS X El Capitan installer app as well, just keep in mind the file name of the installer will change for beta versions and final version, so users would need to adjust that portion of the command syntax as necessary.