There are a few weeks left, Apple will roll out the stable macOS Mojave version. If you’ve already joined the beta program and want to leave it out, you can now downgrade back to MacOS High Sierra to wait for the official Mojave.
What You Should Know
If you have already installed macOS 10.14 Mojave beta version on a secondary volume partition on your Mac, you can quickly delete that volume.
Otherwise, the process will be very easy if you already created a Time Machine backup before setting up the Mojave beta version. The entire Time Machine backup can be restored to put your Mac return to the state before installing macOS Mojave. You can revert your files to that state, so back up any new files or files, which have changed since the Mojave beta was installed and you could restore them afterward.
If there is not a full Time Machine backup that you have created on your MacOS High Sierra, you need to install this version from scratch. Everything such as your personal files, installed applications will be lost, so make sure you have everything backed up first.
How to Delete a Secondary Mojave Partition
If you have already created a secondary partition for macOS Mojave, the process is simple. If you could not remember if you created a secondary partition, you didn’t. The default option is updating from a stable High Sierra version to the Mojave beta.
First, boot your Mac into High Sierra. Reboot your Mac. When it starts, press & hold the “Option” button and you can access the Startup Manager and choose the High Sierra drive. After that, head to Finder > Applications > Utilities > Disk Utility, and choose the Mojave volume and then click the “–” button above Volume to remove it.
Warning: All files on your macOS Mojave volume will be lost, so back up anything important before you do this.
How to Restore High Sierra from a Backup
If there is a High Sierra backup and you want to restore, you can do it from Recovery Mode. But you have to format the macOS Mojave drive before restoring the backup.
Boot your Mac into Recovery Mode by pressing and holding Command+ R keys when it boots. Your Mac will then download the recovery files from Apple’s servers and load Recovery Mode normally.
- Now, from Recovery Mode, click on the “Disk Utility” option.
- Choose the macOS Mojave volume and click on “Erase” from the toolbar. Set the volume a new name—like “macOS High Sierra”—and then click on “Erase” to continue the process.
Warning: The process will remove the contents of the macOS Mojave volume even including your personal files. So make sure the important files are backed up first.
Now, exit the Disk Utility app and return to the main Recovery Mode screen. Next, click on “Restore from Time Machine Backup.”
When you’re prompted to choose a backup, select the recent one that you have made on macOS High Sierra. Finally, select the drive that you want to restore your Mac.
The process could take a while, depending on the size of the backup as well as the speed of your backup drive. Once it’s done, your macOS High Sierra system will be brought back, as it was when creating the backup.
How to Format Your Mac to Install High Sierra
If you don’t have any High Sierra backup available, you need to start over from scratch. It means you will need to erase your macOS Mojave system and then install a fresh High Sierra version. You will also need to create High Sierra installation media. In case your Mac originally comes with High Sierra, you don’t have to create a bootable installer.
However, if your Mac does not originally come with High Sierra, you need to create a High Sierra from macOS Mojave. To do so, visit the macOS High Sierra page and click on “View in App Store” and“Get” to download MacOS High Sierra.
Click on the “Download” button when you are prompted if you want to download High Sierra. The file size is about 5.22 GB.
You will see a warning that High Sierra is too old and can’t be opened on Mojave. Don’t worry about that
Once the download is done, use the Terminal to create a bootable USB installer. You will need to prepare an at least 8GB USB drive for storing files.
Plug the USB drive into your Mac and launch a Terminal window by heading to Finder > Applications > Utilities > Terminal. Next, enter the following command, and point it at the path of the USB drive. For example, if the USB drive is named “HighSierra” and is mounted at /Volumes/HighSierra after plugging it in, open a Terminal and run the following command:
sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/HighSierra --applicationpath /Applications/Install\ macOS\ High\ Sierra.app
The command will then take on the “Copying installer files to disk” phase. It will need a while, so you should be patient.
Once the process is done, reboot your Mac and hold Command+ R keys to boot into Recovery Mode. Next, click on the “Disk Utility” shortcut in Recovery Mode.
Choose your macOS Mojave volume and click on the “Erase” button. Next, enter a new name for the volume.
If your Mac originally comes with High Sierra, you can quit Disk Utility and select the “Reinstall macOS” option from Recovery Mode to install High Sierra again.
If your Mac does not originally come with High Sierra, simply reboot your Mac and quickly hold the “Option” key while it’s booting up to go into the Startup Manager. From there, choose the “Install macOS High Sierra” section to boot your computer from the drive and start installing MacOS High Sierra on your Mac.
Now, wait for the stable MacOS Mojave and you will be updated to it normally. Let’s know if there are any issues happening with you.