Has anyone run into issues installing ubuntu 18.04 on an external ssd drive using the mac mini 2018? I'm receiving error message regarding the thunderbolt ports on the mac mini during the installation.


After struggling with this for many hours I thought I'd provide an updated write-up for installing Ubuntu 20.04 on a Mac mini 2018 running macOS Catalina.

The most important sources turned out to be a great answer here that also covers installing Windows, but lacks information about installing on newer Macs with a T2 chip. Another source is this Reddit post which, however, is more complicated than necessary IMO. So here goes:


For the installation, you're going to need a bootable USB stick and a partition on your Mac's internal drive or an external drive where the final installation shall reside.

  1. Follow the instructions in the link above for creating the boot stick.
  2. For the Linux partition, open Disk Utility, select the hard drive where you want to install Ubuntu and click "Partition". You are going to need at least 25 GB - I chose to allocate 50 GB which is enough for my use case.
  3. Select your new partition and click "Erase". Choose some name like "UBUNTU", Format "MS-DOS (FAT)" and Scheme "GUID Partition Map".

Boot and Install Ubuntu

  1. Disable the T2 Boot Security: Reboot and hold Command+R. Start the "Startup Security Utility". Select "No Security" and "Allow Booting from External Drive".
  2. Reboot your Mac and hold the Option key while it is starting. Select the "EFI Drive" - that is the boot stick you just created. You're presented with various options of which you'll choose the first one "Ubuntu".
  3. In the dialog that will appear, select "Try Ubuntu" to enter a live session.
  4. Now comes the part that took me forever to figure out: launch the Ubuntu installer via terminal with the command ubiquity -b. This way the installer won't try to install the GRUB boot manager which always failed for me. A warning will appear, that deprecated modules are being used. This seems to be due to ubiquity's implementation and can be ignored. Just wait for the installer window to appear and then proceed (this can take a few seconds).
  5. When asked where to install, select "Something Different". Highlight the previously created partition (the 50 GB one in my case) and click "Change". Select ext4 formatting, click the checkbox that you want the partition to be formatted and enter "/" (without quotes) as "Mount point".
  6. If you're on an external drive, be sure to select the right partition in the drop down menu (not just the drive). Then continue the installation.

Install rEFInd

Installing Ubuntu without its boot manager GRUB means that you cannot easily start it by holding Option when booting your Mac. That's why you'll install rEFInd which replaces the default boot manager of your Mac.

  1. Enter your Mac's recovery options by restaring and holding command+R. There, open a terminal and execute csrutil disable. Do not forget turning this back on again later!
  2. Boot back into macOS by restarting. You may have to hold Option and select your Macintosh-HD drive.
  3. Download from the link above.
  4. Open a new Terminal, drag "refind-install" into your terminal window and execute it by pressing Enter.
  5. Now you repeat step 1, this time typing csrutilenable.


Everything should work fine now. When you turn on your Mac, you're presented with the rEFInd screen where you can select which OS to boot. Have fun!


  • It seems some driver issues that previously existed (e.g. Bluetooth, affecting Magic Keyboard & Mouse) have been sorted out in the latest version of Ubuntu. One problem I did encounter was that scrolling on my Magic Mouse 2 didn't work. For that, consult this post.
  • As noted by David Anderson (see comments below), it is important to install Ubuntu first and rEFInd second.
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  • In Preparations, step 2: I think you mean to create the new partition on your internal drive - NOT on the USB. IMHO, you could improve the answer by making that a bit more clear. – Seamus Jun 4 at 10:05
  • In my case, I also wish to install Ubuntu 20.04 alongside macOS (i.e. dual boot), but on a late-2011 Macbook Pro currently running High Sierra. There is no T2 chip in this system. Can this step simply be omitted? If so, a couple of words to make that clear would help. – Seamus Jun 4 at 10:09
  • Step 3 under Boot & Install Ubuntu states, launch the Ubuntu installer via terminal with the command ubiquity -b. But this Ubuntu documentation does not show the -b option. Could you please reference the documentation for this? – Seamus Jun 4 at 10:15
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    @DavidAnderson Yes, I did install Ubuntu 20.04 LTS on the internal SSD of a Mac mini 2018. I did a complete reinstall and update of macOS Catalina before performing the steps that I describe above. I am updating the answer to reflect that. – japhwil Jun 4 at 14:25
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    Let us continue this discussion in chat. – japhwil Jun 4 at 17:24

I successfully installed 19.04 on the Mac Mini 2018. Had to add kernel params noapic efi=noruntime to USB Live Media to boot into live mode. Then I installed it onto an external USB-C drive and also added the aforementioned params to the GRUB config.

Now I can boot Ubuntu 19.04 from the external USB-C drive, but without some drivers (e.g. bluetooth and audio are not working).

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From what I've gathered, Apple is giving the middle finder to third party OS's (other than Windows) with the T2-enabled machines, at least by default. You have to go into recovery mode and disable Secure Boot before running anything other than macOS, even on an external drive.

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