I am unable to shrink my macOS volume/disk on my Intel 2019 15" MBP with a 1Tb disk to make space (128gb) for installing a linux distro in dual boot configuration.

Disk utility in macOS will not let me change anything in relation to disk size and it appears my macOS install is already taking up the full amount of space in the drive.

I had previously used Bootcamp to install windows 10/11 in a dual boot config, but i subsequently removed windows using Bootcamp and reclaimed the space.

I have disabled File Vault and also ran FirstAid on my disk and it reports no errors.

Within Disk Utility I see this message in relation to my disk:

This container has 373.14 GB used space. Its minimum size is 1 TB. Snapshot tidemarks can raise the minimum size above the used size. This container can’t be split because the resulting containers would be too small.

If I hold down command a little circle appears at the top of the line shown in the screen shot below, and I should be able to drag this to change the size of my disk but nothing happens when i do.

I have tried holding command at boot and using disk utility outside of macOS but i get the same thing.

As you can see from the screen shot I am using less than 400gb of a 1tb disk so I think I should be able to shrink the disk by 128gb without any probs.

I also tried resizing my macOS install partition using the Debian 12 installer but that errored out saying it was unable to modify the disk.

eDisk Utility Screenshot

Mac Model and Spec


I thought I would see if I could use bootcamp to recreate a partition for a windows install and then use that for linux, but when i try to run bootcamp I get:

Bootcamp space error message

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Any suggestions will be much appreciated, thank you.

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2 Answers 2


After much searching and trying all sorts, I bit the bullet, backed up my files and used the recovery/bios feature of my 2019 15" intel MBP to reinstall macOS - during this process I was able to select the size of the disk for the new macOS install and create a partition for use with linux in a dual boot...

This involved holding command+r during boot and then selecting to delete/erase my HD, creating a main 800gb partition for macOS which then left 200gb free - and then selecting to reinstall macOS on the 800gb partition.

Unrelated - but doing all this was a bit of a waste of time, I was trying to test the T2 versions of Arch and Ubuntu 24.04 to see if they would run well on my 2019 MBP hardware...

Even though I had a free 200gb partition, T2 Arch still wanted to reformat my entire disk...

So I switched to T2 version of Ubuntu 24.04.

This installed successfully on the 200gb partition but overwrote the macOS efi partition so now my Mac boots into linux by default - if I hold option before boot, I can select macOS as needed... and I am sure I can reset/correct this without to much pain.

In Ubuntu I could not get the wi-fi driver to work and I also found that bluetooth was a little hit and miss with my mouse and keyboard... other than that Ubuntu seemed to run quite well...

Having said all this, it seems reinstalling macOS has improved the performance of my system slightly and I will now be able to re-size my partition if needed in future...

Additional: I also tried to resize the partition after installing the latest macOS Sonoma 14.5 update but this didn't not help with the resizing issue so I decided to just go with the reinstalling of macOS...

All in all, putting a fresh install of maOS was probably a good thing as I had just kept upgrading the original 2019 macOS without reinstalling the OS each time a new version came out...


Boot from an external Linux usb or the Apple Internet Recovery. You can find multiple options, pick one you're comfortable with.

"No Bag Entry" when trying to reinstall Sierra

This first link shows that you need to be sure the time is correct on the machine.


This second link details how to create a Linux USB

Once you do that, you can use the partition tools for that software.

You've stated that you "messed" with the partitions. So, you should fix those also.

You could also use the macOS Terminal tool "diskutil".

diskutil addpartition disk0s1 APFS "Macintosh HD" 0

See this Apple Discussion

  • Your answer could be improved with additional supporting information. Please edit to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center.
    – Community Bot
    Commented May 7 at 15:57
  • It's not really clear how the links (especially the first one) are relevant. Also, the question is about shrinking a partition, can you elaborate on how this actually can be accomplished from Recovery or Linux?
    – nohillside
    Commented May 7 at 17:04
  • Sorry my friend, but i have already tried using a USB thumb drive to boot a linux live distro to resize my disk and I have also tried using Disk Utility and recovery options as well as bootcamp - but thanks for your input.
    – Mark Smith
    Commented May 7 at 20:06
  • The first link shows that you need to be sure the time is correct on the machine. The second link details how to create a Linux USB. Once you do that, you can use the partition tools for that software. You spent more time trying to tell me that I was wrong than you did on actually doing something. SMH You could also use the macOS Terminal tool "diskutil".
    – I O
    Commented May 9 at 13:01
  • In addition, you may have erased your original recovery partition, so, you may need to just start from scratch. Just saying... apple.stackexchange.com/questions/264170/…
    – I O
    Commented May 9 at 13:15

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