How to make a partition with Mac OS Extended Journaled on a SSD with APFS macOS 10.14?

Big Sur which 11.0 not 10.14 can only run on an APFS formatted disk.

Open Disk Utility click on View in the menubar and select Show All Devices.

Highlight the Disk not any of the indented Containers or Volumes.

The Disk is probably called Apple SSD.......

Click on the Partition button.

Click the + button.

Use the toggle on the rim of the circle to create your 50GB partition

give it a name and then at Format select Mac OS Extended (Journaled)

then click Apply.

In the example below my Disk has three partitions.

The first is SSD APFS which has Mojave 10.14 on it which is of course

formatted as APFS, the other two partitions for El Capitan and macOS Sierra

are formatted as Mac OS Extended (Journaled).

Can you share screenshots of what you see in Disk Utility and then a screenshot of Disk Utility

after click ing on the Partition button.

When you open Disk Utility did you click on View in the menubar and select Show All Devices.

This will show the Container Disks and the Volumes under the Disk.

To get the partition screen as active you must click on the Disk not any indented Volumes or Containers

and then click on the Partition button. As I said above the Disk is probably called Apple SSD.....

In my example below my Disk is called CT500MX500SSD1 Media

I am working from macOS Mojave so I am hoping that Apple haven't completely changed the way Disk Utility in Big Sur

behaves so some screenshots would be nice.

Ok I think I might know why this is not working for you I forgot to tell you to boot up to your

Recovery HD. You can also do this by booting to a bootable USB installer if you have created one.

Restart your mac while pressing and holding down the Command and R keys, or the option/ alt

key if booting from a bootable USB installer.

In a few minutes your mac will boot to your Recovery HD or USB and you should see a Utilities panel.

Select Disk Utility and press Continue.

Click View in the menubar and select Show All Devices.

Highlight Aura Pro X2 Media as shown in this screenshot you sent me.

Now click on the Partition button. The Disk should now show a striped section which is the used space on the Disk and a

section without stripes which is the free space. It is this free space that you should be able to create your new partition with.

The plus button should be available now.

If you can post screenshots you will probably have to use a phone or camera to take the screenshots as you are booted to your Recovery HD/ USB and the usual screenshot keyboard shortcuts are not available.

Hope this has a better outcome now.

FWIW, you can't install a version of macOS that is earlier then what your Mac was shipped with. You don't mention which Mac or what year it is.

You're welcome. First, are you running Big Sur 11.* or Mojave 10.14? There is no "macOS 10.14 Big Sur".

I see you have an answer. Good luck.