The Trifecta: How to Run Three OSes on an Intel Mac
2 min readNov 4, 2022
I purchased an Intel 27" iMac over the summer and especially enjoyed the crisp sound. During Week 44 of this year, I decided to triple boot this computer so as to run machine learning models on Linux/Ubuntu, create in Office 365/run various software on Windows 10 Pro, and all that smooth jazz on Mac OS as well.
Total estimated time: 1.5-3 hours.
I made sure to connect wired peripherals during this process. I found this method to work best, and I am now up and running on three operating systems on this beautiful machine:
- Ensure that the Intel Mac’s hard drive is still Fused, so to speak, because Mac OS’s BootCamp requires a Fusion hard drive to create a Windows-compatible partition. If you see the Fusion error message when trying to run BootCamp, restart your Mac in Recovery Mode, use Disk Utility to reset your hard drive to its initial Fusion state by running diskutil resetFusion, and then reinstall Mac OS within recovery mode.
- Install Windows on your Mac using BootCamp and be sure to save room on the Mac partition for installing Ubuntu later. * Using a Windows computer to create a bootable install USB works well. Or, you can download the .iso to your Mac. * BootCamp is designed to write the specific required drivers to Windows for your Mac, and I found that trying to copy the drivers manually was tough.
- Once you’re up and running on Windows, boot up your computer in Recovery Mode and run csrutil disable in Terminal to disable System Integrity Protection. You can and should re-enable SIP after installing all OSes by running csrutil enable in Recovery Mode.
- Boot up again in Mac OS and install rEFInd by downloading the binary and then running ./refind-install in Terminal from its directory.
- Create a bootable Ubuntu installation USB drive. And use Disk Utility to create a partition formatted as MS-DOS on which to install Ubuntu.
- Boot up your machine and you should see the rEFInd boot selection screen. Now you can install Ubuntu by following these steps.
- Badabim badaboom.
