[Guide] Multi Boot Ubuntu and macOS (UEFI) on Separate Drives

[EliteMacx86]

Multi Booting Ubuntu and macOS on two separate drives is simple as Multi Booting Ubuntu and macOS on single drive.
(See https://www.elitemacx86.com/threads/guide-multi-boot-ubuntu-and-macos-uefi-on-single-drive.113/)

This guide explains Multi Boot Ubuntu and macOS on two separate drives. Multi Booting on two separate drives is the best way to multi boot. The current release is Ubuntu and macOS High Sierra. Ubuntu and High Sierra will be used for this guide.

This guide is bit lengthy so has been divided into 5 chapters.
The chapters includes.

Requirements

• 3x USB Flash Drive for Windows, macOS, Ubuntu and Post-Installation
• A working Internet connection to download the files.

Step 1: Creating macOS Installation USB

The very first step is to create the Installation USB for macOS High Sierra. To create Installation USB for macOS Sierra, follow the guide here.

Step 2: Creating Ubuntu Bootable USB

Now after creating macOS High Sierra Installation USB, the next step is to create a Bootable USB for Ubuntu. You've two ways to create the Bootable USB either on Windows or Mac.

If you're having a system running Windows, follow the guide here.

If you're having access to Mac, follow the guide here.

Step 3: Copy Post installation tools and Drivers

Insert your third USB Flash Drive and copy the necessary drives for Ubuntu, and tools and kexts for Mac. Once the network is enabled, you can continue with the progress.

So now as you’re having macOS High Sierra Installation USB, Ubuntu Bootable USB and the post installation tools and drivers, so you’re ready to Multi Boot on your computer.

Step 4: BIOS Settings
If you're installing on a desktop with AMI UEFI, the options are simple. For other systems using a different vendor, make sure to set your BIOS or UEFI to Optimized Defaults, and the SATA Mode to AHCI.

Here's a Recommended BIOS/UEFI Settings for Optimal performance.

To access your BIOS/UEFI, press and hold Delete key on your Keyboard. The key maybe different in your case. Refer to your Motherboard Guide/Manual.

• Set Optimized Defaults.
• Set X.M.P. Memory Profile to Profile 1 (Optional, if using a High Frequency RAM).
• Set Windows 8/10 Features to Other OS.
• Set Network Stack to Disabled.
• Set Secure Boot to Disabled.
• Set Intel Platform Trust Technology (PTT) to Disabled.
• Set XHCI Hand-Off to Enabled.
• Set SATA Mode to AHCI.
• Set Internal Graphics to Auto.
• If your system has a VT-d Option, Disable it.
• If your system has Intel Virtualization Technology, Enable it.
• If your system has Serial Port, Disable it.
• If your system has Parallel Port, Disable it.
• If your system has Fast Boot Option, Disable it.
• Save & Exit Setup.

Note :

• If you're using a external Graphics Card for your build, such as NVIDIA or AMD GPU, set Initial Display Output to PCIe Slot 1

Step 6: Installing macOS High Sierra

Now the next step is to install macOS Sierra. Follow How to Install macOS High Sierra for this guide. Please be sure to follow the appropriate guide as per your build.

Also will recommend to complete each specific install at one time to avoid confusions and hassle free installation.

Once the post installation is completed for macOS, Shut Down your PC.

 

[EliteMacx86]

Installing Ubuntu
Step 7: Preparation for installing Ubuntu

So after installing macOS High Sierra and completing post installation, the next step is install Windows 10. Before you install Windows 10, you’ll need to create a free partition. To create a free partition, follow the steps below.

@Gbilato has written a great guide about using Disk Utility on Mac. You can follow How to Use Disk Utility on Mac

But to make it moreeasy and avoi confusion, i'll explain the required process.

Go to Utilities and open Disk Utility.

Now select your Drive, not the partition.

Click on partition button and then click on + (plus) button.

Under Name you can type any name but for instance we’ll be using Windows 10.

Under Format select Mac OS Extended (Journaled).

Under Size you can choose according to your Hard Drive and workload on Ubuntu. But as stated above, we’ll be using 160 Gigs each for Ubuntu and macOS High Sierra.

Click on Apply button and then click on partition button.

Click on Continue.

Now it will create a free partition for Ubuntu.

When done, close Disk Utility.

The created partition will appear on your Desktop.

Now restart your PC.

Step 8: Installing Ubuntu

While restarting your PC, plug your Ubuntu Flash Drive.

Press F12 to enter your Boot Menu.

Select your USB Flash Drive with the UEFI Prefix.
Select Install Ubuntu and press enter key
When at welcome screen, select your language and click on Continue
Select Install third party software for Graphics and Wi-Fi hardware, MP3 and other media and click on Continue
When at Installation type, select Something else and click on Continue
Select free space, this is the space which we created using Windows Installation Drive in the third part of this guide
Now assign the space for the Ubuntu installation
Note :
Do not assign the whole space as you need to also assign space for swap area
Type 90000
Select Use as : Ext4 journaling file system
Under Mount Point select / and click on OK
Select free space 10000 MB and click on + button
Under use as select Swap area and click on OK
Select /dev/sdb5 ext4 /
Click on Install Now
Click on Continue
Select your Country and click on Continue
Select your Keyboard Layout and click on Continue
Now Ubuntu will copy files. This process will take some time to complete.
When the installation completes, it will show a confirmation message
Click on Restart now and eject your Ubuntu installation USB
Select Ubuntu and press enter to boot
Login to your user name
Complete the post installation

Now all the fixes have been applied. The Post installation has been completed successfully for Windows 10. The macOS High Sierra has been installed already.

Now eject your second USB Flash Drive and Shut Down your PC.

 

[EliteMacx86]

Configure System for Multi Boot

Step 2: Configure PC for Dual Boot

Connect your macOS drive back.
Start your PC
Press DEL key to enter your BIOS Menu. Navigate to BIOS Features Tab and change the first boot option to the UEFI OS internal drive instead of the Windows Boot Manager.

Select your Hard Drive with UEFI Prefix so that the Clover boots first.

Go to Save & Exit Tab and Save the changes and exit the UEFI BIOS.

Step 10: Restart your System!

After restarting your PC, it will boot to Clover Welcome screen automatically. You can choose between which OS to Boot either Windows or macOS.

And you're done!
Multi Boot on Separate Drive is just how simple it is.