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.

Step 1

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).

Step 2

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.

Step 3

Once the download for macOS Sierra has been completed you will be automatically presented with the Sierra Installer. Quit the installer using the top menu.

Step 4

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)

Step 5

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).

Credits

Shout outs to the guys at BetaNews.com which I used as a source of reference for this post

Author: TFindley

Tristan is an IT Professional, Photographer and motorcycle enthusiast. Working full-time as a Systems Administrator for Royal Holloway, but running his own photography company, and the occasional IT Contract. Tristan has been riding motorcycles since 2016, and is the original author of "My First Motorcycle", the forerunner to this site. He built it with the intention of providing a resource to those interested in riding, and to give something back to the community that had helped get him started in the world of motorcycles. View all posts by TFindley

2 thoughts on “Building an macOS Sierra USB Stick”

Mike Northcutt says:

April 16, 2017 at 1:18 am

Hi. I’ll try this (terminal method). I’ve spent the last 3 hours unsuccessfully trying to get Diskmaker X to work with sierra. I would research issues with this and see about posting an update. I’ve had issues with error -10006 code, unmounting issues during sierra transfer to flash drive, etc. Also issues after successfully installing the installer then having it not be bootable in startup disk options. I’m using usb 3.0 disk. Best regards. Mike N.

1. TFindley says:
  
  August 11, 2017 at 12:20 pm
  
  Hi Mike
  
  Thanks for reaching out, and sorry for the late response. I’ve personally found the entire process of building a macOS USB stick to be riddled with uncertainty and problems. Sometimes it works, and other times It would just spit out a load of random errors at you. Othertimes it would appear to work until you tried to boot off the stick only to find out that it did not build correctly. Apple certainly don’t make it as easy as it could be. My previous method of using Apple Automator with an additional Automator task to build an Apple Mountain Lion Bootable USB Stick (that I documented back in 2012) all of a sudden stopped working, hence writing this guide. I’ll try to rebuild a new Sierra USB when I get a few minutes, and also try it with High Sierra when it comes out.
  
  As you posted this a few months ago, did you ever happen to find your own solution for this?
  
  All the best!
  Tristan