Experienced Mac users can create MacOS Catalina's bootable installer using a USB flash drive. It offers an easy way to install the beta version of macOS 10.15 on a test Mac, either on a separate disk or on a partition.
Using a bootable installation disk also makes it easy to format and split disks, making it easy to install a clean beta of macOS Catalina 10.15 on a target Mac. Of course, the boot installer can also be used to upgrade an existing installation to MacOS Catalina beta.
This tutorial will show you how to create a bootable USB-drive for MacOS Catalina 10.15 beta.
Requirements for creating MacOS Catalina 10.15 Beta USB Installer
To create a bootable installation disc for MacOS Catalina beta, you need the following:
We assume that you have knowledge and understanding of the command line. Creating a bootable USB-drive using this method requires the use of the Terminal, and the syntax must be exact to avoid mistakenly deleting the wrong disk. If you don’t feel comfortable on the command line, it’s probably best to skip this.
How to create a bootable MacOS Catalina 10.15 Beta USB installer
Connect a USB flash drive to Mac
Open the Terminal application located in the / Applications / Utilities / directory
Enter the following command at the terminal command line, replacing “UNTITLED” with the name of the USB flash drive of the device you want to convert to the Catalina boot installer:
sudo / Applications / Install macOS 10.15 Beta.app/Contents/Resources/createinstallmedia --volume / Volumes / UNTITLED && echo Catalina Startup disk created
Make sure the syntax is correct, then press Enter / Return
Log in with the administrator password (this is required to use the sudo command)
Let the installer creation process complete, it may take some time.
After creating a MacOS Catalina 10.15 installation USB disk, you can use it like any other bootable Mac disk.
You can immediately launch the installer from the MacOS Catalina 10.15 boot disk, otherwise you can use it to boot any Mac compatible with MacOS Catalina.
After completing the creation of the MacOS Mojave 10.14 Installation USB Disk, you can use it just like any other Mac OS boot disk. You can immediately launch the installer, or eject the disk and use it on another Mac, or reboot the computer with a connected one so that you can boot from the Mojave Beta installer to install the update, perform a clean install, or partition the Mac to install the beta – Mojave version for this section. There are many options for using the MacOS Mojave installation disk.
Please note that if you encounter a “command not found” error, this is probably due to a syntax error, and you should check the command being executed, or because the Install macOS 10.15 Beta.app application is not in the / Applications as expected.
The above steps work to create a MacOS Catalina Beta Boot Installer disk, usually the public Beta has an installer application with a different name, and therefore the command to create a bootable USB drive for the MacOS Catalina Public Beta is slightly different. We will update it when it is released and available.
How to download MacOS Catalina Beta USB Installer
Connect the MacOS Catalina 10.15 beta drive to install to the Mac on which you want to install Catalina.
Immediately hold down the OPTION key while loading, continue to hold Option until you see the boot menu.
Select the volume to install the beta version of macOS Catalina 10.15 to download
After downloading from the MacOS Catalina installer, you can format the target disk using Disk Utility, select the disk to install macOS 10.15, use Time Machine, access the Terminal from the recovery mode and perform any other typical operation performed from the boot install disk.
Have you made a boot disk to install the beta version of macOS Catalina? Do you have another way to create a boot disk for MacOS 10.15? Share your comments and experiences below!