In this step-by-step tutorial, we explain how to convert your USB thumb drive into a macOS 27 installer so you can deploy macOS Golden Gate on multiple Macs without having to download the massive 17 GB file on each computer every single time.
Grab your external drive and make sure it has nothing of importance, as the drive will be fully erased and formatted during the process.
Note: We also have tutorials for creating a USB installer for macOS Tahoe and macOS Sequoia. Check those out as well if needed.
Create a bootable USB installer for macOS 27 Golden Gate
1) Download the macOS 27 developer beta file directly from Apple using this link. You can learn more about downloading the macOS installer file in our recent guide on installing macOS Golden Gate on a different partition of the same Mac.
2) Once the ~18 GB macOS 27 file is downloaded, double-click the InstallAssistant.pkg file and go through the simple installation process (Continue > Install > Close). Once again, we have explained it in our macOS Golden Gate installation guide.
3) Go to Finder Applications folder, and you should see the ‘Install macOS 27 Beta’ app there.
Now, Control-click or right-click on it and choose Rename. Change the name to GoldenGate (without spaces), as seen in the screenshot below. Of course, you can rename it to anything you want, but for simplicity and to avoid having to tweak the Terminal command in Step 7 below, I recommend you do as I say.
4) Connect your external thumb drive to your Mac.
5) Open Disk Utility, select the external drive in the left sidebar, and click Erase.
6) Set the following and click Erase:
- Name: Set it exactly to macOS27 (without spaces)
- Format: Mac OS Extended (Journaled)
- Scheme (if you see it): GUID Partition Map
Wait for Disk Utility to erase and reformat your external drive. Leave the USB thumb drive connected to your Mac and make sure you see it on the Desktop and/or in the Finder sidebar.
7) Open Terminal, enter the following command, and press the return / enter key.
sudo /Applications/GoldenGate.app/Contents/Resources/createinstallmedia --volume /Volumes/macOS27
Note: GoldenGate.app is the name we set in Step 3 above. And macOS27 is the name of the USB thumb drive we set in Step 6 above. If you used different names in Steps 3 and 6, be sure to update the Terminal command accordingly and use that.
8) Enter your Mac’s password (you won’t see any visual confirmation on the Terminal window) and press the return key.
9) Then type Y and hit the return key to begin the process.
Terminal will erase the external disk, then copy the macOS 27 installer to it, effectively turning it into a macOS Golden Gate deployer.
As Terminal progresses, you’ll see the percentage increase in increments of 10.
Do not stop the process or eject the file even if the ‘Copying to disk’ level reaches 100%. Instead, consider the process completed only when you see “Install media now available at “/Volumes/Install macOS 27 Beta” as shown with green underlines in the screenshot below.
You can now safely eject the USB thumb drive, which is now a macOS 27 installer.
Install macOS 27 on Mac using the bootable USB installer
Follow these steps to use the USB installer to deploy macOS 27 Golden Gate on a Mac (make sure the Mac has an Apple silicon chip):
1) Connect your USB thumb drive to the Mac where you want to install macOS Golden Gate.
2) Optional: Create a new volume on your disk if you want to install macOS 27 on a separate partition.
3) Shut down your Mac and wait for a minute.
4) Press and hold the power button until you see the ‘Loading startup options’ on the screen.
5) You should now see the Install macOS 27 Beta on the screen. Click Continue below it, then follow the steps to install macOS 27 on the same disk or a different one (if you had earlier created a new volume in Disk Utility).
6) Repeat the above steps to deploy macOS 27 on other Macs using the same USB bootable installer.
If you ever want to use this drive for anything else, just erase and reformat it using Disk Utility or by right-clicking on its name on the Desktop.
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