The 2017 WWDC keynote saw the announcement of Apple’s next operating system, named (somewhat incrementally) macOS High Sierra. As is their custom, the first developer beta of the OS was released along with the keynote, so that testing could begin.
In this guide, we’ll demonstrate how to create a USB install drive from your downloaded High Sierra beta, so that you can install it to multiple machines without re-downloading, perform clean installs, and keep a copy safe for troubleshooting purposes.
Remember, at the time of writing, macOS High Sierra is a developer beta only. This means it requires a paid developer account to download. If you do not have access to the developer beta I advise signing up for the public beta instead, and coming back to this guide once you’ve got your hands on the install files.
All you’ll need for this guide is a copy of the macOS High Sierra beta and a USB stick/external drive of at least 8GB capacity.
How to create a macOS High Sierra installer
1) Download the High Sierra Beta installer, and ensure that it is in your /Applications folder. This is the default download location through the Mac App Store anyway. If it is elsewhere on your computer, move it to the Applications folder. The guide will be marginally easier if you leave its name as the default: Install macOS 10.13 Beta.
2) Insert your >=8GB USB stick. If the stick is not already formatted as GUID Partition Map and Mac OS Extended (Journaled), launch the Disk Utility application and format it thusly. This will wipe all data from the drive.
3) Name the USB drive USB. This will make the guide marginally easier. Make sure there are no other volumes mounted with the same name.
4) Open a Terminal window, and paste in the following command to move the Beta Installer to the USB and make it bootable:
sudo /Applications/Install\ macOS\ 10.13\ Beta.app/Contents/Resources/createinstallmedia --volume /Volumes/USB --applicationpath /Applications/Install\ macOS\ 10.13\ Beta.app --nointeraction
If you renamed the High Sierra Installer or the USB drive to something other than what I advised, you must edit the command to reflect your chosen names. If you moved the Beta Installer out of /Applications against my advice, you must edit the command to reflect its current location.
5) Enter your account password when prompted, and the process will begin. The USB drive will be unmounted throughout the process and will disappear from the Desktop. Terminal will provide a readout of the progress; be patient!
Once the files have been copied and the drive has been blessed to make it bootable, your drive will reappear on the Desktop and Terminal will inform you that the process is complete.
How to use the macOS High Sierra USB installer
To use the USB installer simply boot your Mac whilst holding the option/alt (⌥) key. When you see the screen in the image below, select the drive entitled Install macOS 10.13 Beta (it’s not visible in my image, but it will be in your case).
The computer will then boot to the macOS 10.13 High Sierra Beta install screens, and you can deploy it as you see fit.
Remember, it’s devs only at present, but a public beta will be coming very soon! If you have tried it out, I’d love to know your thoughts so far in the comments section below.