Why Create a macOS Golden Gate USB Installer?

While macOS Golden Gate can be installed directly via Software Update, having a bootable USB installer offers significant advantages. It allows you to upgrade multiple Macs without downloading the full installer each time, which is especially beneficial for environments with multiple machines or slow internet connections. It also provides a reliable fallback for performing clean installs or troubleshooting system issues. This tutorial walks you through the entire process, from selecting the right USB drive to executing the necessary Terminal commands, ensuring you end up with a fully functional installer.

Selecting a USB Drive

You will need a blank USB drive with at least 16GB of storage capacity. Most modern flash drives, external SSDs, or even SD cards (with an adapter) work, but a drive with both USB-C and USB-A connectors offers maximum flexibility. For example, a SanDisk 128GB flash drive with dual connectors is a popular choice. Ensure the drive is empty or that you have backed up any existing data, as the creation process will completely erase its contents.

Downloading the macOS Golden Gate Installer

There are several ways to obtain the macOS Golden Gate installer, but the most efficient method is via the Terminal using the softwareupdate command. This approach downloads the installer directly to your Applications folder, ready for USB creation. Before beginning, if you are installing a beta version, you must enable Beta Updates in System Settings > General > Software Update.

Step 1: Open a new Terminal window and run the following command to list all available full installers:

softwareupdate --list-full-installers

This will output a list of available macOS versions, including their version numbers. Note the exact version number for macOS Golden Gate (e.g., 27.0 for the final release, or a beta number like 27.1).

Step 2: Use the following command, replacing the version number with the one you noted from Step 1:

softwareupdate --fetch-full-installer --full-installer-version 27.0

Press Return and wait for the download to complete. The installer will be saved as Install macOS Golden Gate (or Install macOS Golden Gate Beta for pre-release versions) in your Applications folder.

Creating the USB Installer

With the installer downloaded, you can now create the bootable USB drive. This process uses the createinstallmedia tool located inside the installer package.

Step 3: Navigate to Applications in Finder, right-click on Install macOS Golden Gate (or the beta version), and select Show Package Contents. Then open Contents > Resources. Inside this folder you will find a file named createinstallmedia.

Step 4: In Terminal, type sudo followed by a space. This command requires administrator privileges.

Step 5: Drag and drop the createinstallmedia file from the Resources folder into the Terminal window. Then type a space followed by --volume and another space. Do not press Return yet.

Step 6: Connect your USB drive to the Mac. Open Finder and locate the drive under Locations. Make note of its name and ensure it contains no important data. If the drive is formatted as APFS, it must be reformatted because createinstallmedia requires Mac OS Extended (Journaled). To reformat, open Applications > Utilities > Disk Utility, select the USB drive, click Erase, choose Mac OS Extended (Journaled) as the format, and click Erase again.

Step 7: In Finder, select Go > Go to Folder… and type /Volumes to see all mounted volumes. Identify your USB drive’s volume (e.g., MyUSB).

Step 8: Drag and drop that volume from the /Volumes window into the Terminal window, after the --volume flag. Your command should now look something like:

sudo /Applications/Install\ macOS\ Golden\ Gate.app/Contents/Resources/createinstallmedia --volume /Volumes/MyUSB

Step 9: Press Return. Terminal will prompt for your administrator password. Enter it (the cursor will not move) and press Return again. Then it will ask for confirmation to erase the drive. Type y and press Return. If Terminal requests permission to access files on the removable volume, click OK.

Step 10: The process begins by erasing the USB drive, then copying the installer files. This may take several minutes depending on the speed of your drive and system. Once complete, Terminal displays a success message. You can now safely eject the USB drive - it is ready to use as a bootable installer for macOS Golden Gate.

Using the USB Installer

To use the USB installer, connect it to the target Mac, restart the Mac, and hold down the Option (Alt) key immediately after the startup chime. Select the USB drive from the startup manager. You can then install macOS Golden Gate on any compatible Mac, performing a fresh install or upgrading an existing system. This method is especially helpful when installing on multiple Macs or when network speeds are too slow for a direct download.

Installing Beta Versions

If you are installing the macOS Golden Gate beta, it is strongly recommended that you install it on a separate APFS volume on your Mac rather than overwriting your current macOS Tahoe installation. This allows you to evaluate the beta without risking instability on your primary system. Use the USB installer to create a new APFS volume during the installation process, or use Disk Utility beforehand to partition your drive. The steps for creating the USB installer remain identical for beta versions; only the installer name changes slightly (e.g., Install macOS Golden Gate Beta).

Alternative Methods

While the Terminal method is the most direct and reliable, you can also download the installer using the System Settings app under Software Update if you have enabled beta updates. Some users prefer third-party tools like DiskMaker X or Install Disk Creator, but these often rely on the same underlying system commands. The method described here ensures full control and compatibility with both beta and final releases of macOS Golden Gate.

Remember that a USB installer is not required for a standard upgrade; it is an optional but highly useful tool for power users, IT administrators, and anyone who needs to deploy macOS across multiple machines. With this guide, you can create your own installer drive in just a few minutes and be prepared for any installation scenario.

Source: 9to5Mac News