Installing Linux on a Mac isn't quite as straightforward as installing it on an older Windows machine, and you need to make a few tweaks in the installation process. You'll need a USB Thumb stick (with at least 8GB of spare space). You will also lose your macOS/OS X installation (we don't recommend trying to dual-boot OS X and Linux, because they use different filesystems and there are many reported problems).
Be warned that you'll also lose your OS X Recovery Partition, so returning to OS X or macOS can be a more long-winded process, but we have instructions here on how to cope with this: How to restore a Mac without a recovery partition
Here's how to go about installing Linux on a Mac:
- Download your Linux distribution to the Mac. We recommend Ubuntu 16.04.4 LTS if this is your first Linux install. Save the file to your Downloads folder.
- Download and install an app called Etcher from Etcher.io. This will be used to copy the Linux install .ISO file to your USB drive.
- Open Etcher and click the Settings icon in the top-right. Place a tick in Unsafe Mode and click Yes, Continue. Then Click Back.
- Click Select Image. Choose ubuntu-16.04.1-desktop-amd64.iso (or the image you downloaded in Step 1).
- Insert your USB Thumb Drive. A reminder that the US Flash drive will be erased during this installation process. Make sure you've got nothing you want on it.
- Click Change under Select Drive. Look carefully and pick the drive that matches your USB Thumb Drive in size. It should be /dev/disk1 if you only have a single hard drive in your Mac. Or /dev/disk2, /dev/disk3 and so on (if you have more drives attached). Do not pick /dev/disk0. That's your hard drive. Pick /dev/disk0 and you'll wipe your macOS hard drive You've been warned!
- Click Flash! Wait for the iso file to be copied to the USB Flash Drive.
Remove the USB Flash Drive from your Mac.
- Shut down the Mac you want to install Linux on and attach the USB stick.
Power up the Mac while holding down the Option key.
- Choose the EFI Boot option from the startup screen and press Return.
You will see a black and white screen with options to Try Ubuntu and Install Ubuntu. Don't choose either yet, press "e" to edit the boot entry.
- Edit the line that begins with Linux and place the word "nomodeset" after "quiet splash". The whole line should read: "linux /casper/vmlinuz.efi file=/cdrom/preseed/ubuntu.seed boot=casper quiet splash nomodeset --. (See screenshot, below.)
- Ubuntu boots into trial mode.
- Double-click the icon marked "Install Ubuntu".
- Select English and choose Continue.
- Select "Install this third-party software" option and click Continue.
- Click Yes to the /dev/sdb alert.
- Select "Erase disk and install Ubuntu" and click Continue.
- Ensure that Select Drive is displaying the main hard drive. Click Install Now. Click Continue in the alert window.
- Select your location on the map and click Continue.
Choosing your keyboard layout and click Continue.
- Enter the name and password you want to use.
- Click Continue and Linux will begin installing.
When the installation has finished, you can log in using the name and password you chose during installation.
- Install Linux on a Mac using nomodeset
Above: Step 12
When you install Linux on your Mac, it removes all of the OS X installation including the recovery partition. If you want to reinstall OS X, you'll have to create an OS X recovery disk using the thumb stick.