Following on from a rather old guide that I wrote about how to create a OS X Mountain Lion USB Stick, I thought I would share the latest method for creating a macOS Sierra USB Stick.
Hey Siri: How do I build a macOS Sierra USB Stick?
The old method of using the System Image Utility built into macOS / OS X doesn’t appear to work any more, and when I tested using the Customise option in the app and working through Automator process as detailed in my Mountain Lion post, it resulted in a USB Key that was unbootable.
To build a macOS Sierra USB Stick, you will require:
- a Mac computer running at least OS X 10.7 with at least 5GB free disk space
- a single spare USB port
- a USB (2.0 or 3.0) stick at least 8GB in size
- Administrator privileges on the machine you’re using to build the stick
- About 30-60 minutes of time depending on the speed of your internet connection, Mac, and USB Stick.
Open the Apple App Store (Applications > App Store) and find macOS Sierra. If it is no longer on the front page, it can be found by searching, or under the Utilities category. Start Sierra downloading – it is 4.8GB so it may take some time (hence making this Step 1).
Insert a blank USB stick and start Disk Utility (Application > Utilities > Disk Utility).
Select the USB Stick in Disk Utility and select the stick (not the partition – see screenshot). Choose ‘Erase’ from the top and you will be given the option to create a new partition. Use the following settings and choose Erase.
- Name: macOSSierra
- Format: Mac OS Extended (Journaled)
- Scheme: GUID Partition Map
Remember that all data on the stick will be erased!
We have called the stick “macOSSierra” instead of “macOS Sierra” to make the next step easier.
Open Terminal (Applications > Utilities > Terminal) and enter the following command:
sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/macOSSierra --applicationpath /Applications/Install\ macOS\ Sierra.app --nointeraction
Now press Return and you will be prompted to enter your password.
When you type this you will not see any characters appear after the prompt – this is normal behaviour. Once you’ve typed your password press Return and the process will continue.
The process will now install macOS Sierra onto the USB key. Unfortunately there is no progress bar to show you how far along the process is. Do not close the Terminal window until you see your username appear again (see screenshot)
Eject the stick from your Mac using the regular method of ejection.
Now take your stick to another Mac, and with that Mac switched off insert it into the USB port. Now power on the Mac and immediately hold down the Alt (Option) key. A boot menu will be displayed giving you the option to boot from the Macintosh Hard Drive or to boot from the USB Stick to Install macOS Sierra.
Alternative (user friendly) method
Download and run DiskMaker X (formerly Lion DiskMaker) to create a bootable macOS Sierra USB Stick. You will still need to have downloaded macOS Sierra from the Apple App Store (Step 1).
Shout outs to the guys at BetaNews.com which I used as a source of reference for this post