Written by
Amanda Wong
Summary: A complete tutorial on how to dual boot two versions of macOS on your Mac. You can run macOS Sequoia with the macOS Sonoma or earlier versions on the same Mac. Free up disk space with iBoysoft DiskGeeker to ensure available space for the new macOS.
Apple introduced the latest macOS - macOS Sequoia at the opening keynote of WWDC 2024. The public version was finally released on September 16, 2024. If you want to safely install the macOS Sequoia on your Mac, you'd better install the macOS on a separate APFS volume without affecting your previous data.
Then you can boot Mac from two versions of macOS, the latest macOS Sequoia, and another Sonoma/Ventura/Monterey/Big Sur/Catalina. Besides, dual boot Mac is necessary if you want to test software on different macOS, continue to use certain applications with the compatible macOS to avoid the "This package is incompatible with this version of macOS" error, etc. Here, we will walk you through detailed steps to dual-boot two macOS versions.
What needs to be prepared for Mac dual boot?
There are some essential preparations you should make so that you can successfully dual boot MacBook Air/Pro/iMac.
1. Free up space on Mac. Installing a second macOS will occupy gigabytes of storage space. Therefore, you need to make more space on your hard drive for the new macOS. You can delete unwanted files from the Mac startup disk. With iBoysoft DiskGeeker's Space Analyze and Clean Junk features, you can easily remove unused files to release disk space. Free download it to have a try!
2. Back up your Mac. Whatever the changes you will make on your Mac hard drive, you'd better back up your Mac in the first place to avoid data loss caused by accidental misoperations or other errors. If something goes wrong, you can retrieve lost data with the created backup and restore Mac with Time Machine.
Read this post to prepare your Mac to update the new operating system -- macOS Sequoia. Using iBoysoft DiskGeeker to clean the startup disk is crucial for releasing enough space to install macOS Sequoia on your Mac.
How to add a new volume for the second macOS?
You need to create a new volume to install the second macOS. And there are two scenarios. Suppose you are running macOS High Sierra and later versions of macOS, which use APFS. In that case, you can straightforwardly add an APFS volume with the current volumes and data remaining unaffected thanks to the Space Sharing feature of APFS.
On a Mac running older macOS or even Mac OS X, you have to create a new partition to install a second macOS. But it will wipe all the contents on your drive, therefore, backup your Mac before you partition the drive.
Add an APFS volume in Disk Utility:
- Open Disk Utility, tap the View button, and choose Show All Devices.
- Choose the APFS container on the left sidebar.
- Click the + button above the Volume on the toolbar.
- Name the new volume and choose an APFS format.
Create a partition in Disk Utility:
- Boot Mac into macOS Recovery Mode.
- Choose Disk Utility on the macOS Utilities screen.
- Select the primary hard drive and click the Erase button.
- Reselect the drive and tap Partition.
- Allocate space for two partitions and name them.
- Restore the Time Machine backup to one of the partitions.
Get a new volume/partition prepared. Share it to guide more people!
How to Install macOS on the new volume?
With a new volume/partition prepared, you can now download and install the second macOS on the new volume to dual boot Mac. First of all, you need to know which macOS/Mac OS X can your Mac run. If you are using an Apple Silicon Mac, you can only install macOS Big Sur and later versions.
You can head to the Apple Menu > About This Mac to identify your Mac model and visit Apple.com to check whether the macOS you want to install is compatible with your Mac. Then, download the macOS installer from the Apple menu > General > Software Update or the Mac App Store, it will be opened automatically once completed, you should quit there and install it later.
There are effective fixes for the issue can't download macOS Sequoia in Software Update. Follow this post to solve the macOS Sequoia downloading problem and the received error messages like an error occurred while downloading the selected updates.
With the macOS installer prepared, you can follow the steps below to install macOS:
- Open the compatible macOS installer on your Mac.
- Follow the guides on the wizard that pops up to install the software.
- Click Show All Disks when it asks to choose where to install.
- Select the new volume to install macOS.
- Tap Continue, and enter your admin account password.
- Wait for the installation to complete and shut down the Mac.
If the steps above help install macOS on the new volume, you can share it with more people!
How to switch between macOS versions?
Now you have installed two versions of macOS on your Mac, then you can boot your Mac from the one you need with ease. Anytime you want to switch the macOS, you can restart your Mac to change the startup disk.
Steps to boot Mac from the second macOS once:
- Shut down your Intel Mac or Apple Silicon Mac.
- Press and hold the Option key while you start up an Intel Mac, or press and hold the power button
until you see the “Loading startup options” screen of Apple Silicon Mac. - Select the new volume/partition with macOS installed from the available ones.
- Then click the Up arrow or Continue button.
- It will boot your Mac from the disk selected.
The next time you restart the Mac, it will automatically load the startup disk you chose in System Settings, if you want to use another macOS more often, you can change the startup disk with a few steps:
- Head to the Apple menu > System Preferences, then click Startup Disk.
- Click the lock at the bottom left to unlock the preference pane.
- Select the volume/partition you prefer as the startup disk, then click Restart.
You can dual boot two versions of macOS with our help, why not share it to help more?
Conclusion
In this post, we show you how to dual-boot two versions of macOS on the same Mac. You can run a beta/standard version with a public version of macOS at the same time. In addition to installing different macOS, macOS also enables you to run Windows on Intel Macs with the assistance of Boot Camp Assistant, and run Windows on M1 Mac with a virtual machine, emulator, cloud server, etc.
