Missing 2TB of 4TB SSD?

Question

Missing 2TB of 4TB SSD?

Bear with me, I may not be using the terms "partition," "volume" or "container" properly.

I installed a new 4TB SSD brick in my iMac 27-inch 5K (Late 2015). Initial setup had 2TB MacOS partition and a 2TB Bootcamp partition for Windows 10.

I deleted the 2TB Bootcamp partition thinking the space would be restored to the 2TB MacOS partition. What happened instead is that my iMac now thinks it has a 2TB SSD brick.

Here's what's seen in Disk Utility:

and

Here's what Terminal shows:

I'd like to do one of two things: 1) restore the 2TB Bootcamp partition, or 2) restore the drive to a single partition, then re-create a MacOS and Bootcamp partition.

Any suggestions? Thanks in advance!

Posted on Mar 27, 2021 5:57 PM

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Answer 1

Top-ranking reply

Francis Drouillard Author

Level 1

22 points

Mar 28, 2021 9:09 AM in response to Loner T

Thanks for helping. The MacOS partition is fine. I got the free space back by using Terminal. Afterwards, I used Boot Camp Assistant to create a Boot Camp Assistant.

It now looks like I should have skipped creating a new partition in Terminal and used Boot Camp Assistant instead. It's likely that I can now delete the NewAPFS volume in Disk Utility.

Using Terminal and BC Asst. to recover free space

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Answer 2

Mar 27, 2021 7:11 PM in response to Francis Drouillard

As part of using Boot Camp Assistant to remove Windows, the last part is this:

Do one of the following:
- If your Mac has a single internal disk, click Restore.
- If your Mac has multiple internal disks, select the Windows disk, select “Restore disk to a single macOS partition,” then click Continue.

Did that not happen here?

If that restore did happen and things are still messed up, I’d expect to need to back up everything, wipe the whole volume, and reload.

But then I always assume partitioning will cause problems. Always.

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Answer 3

Loner T

Level 9

59,513 points

Mar 27, 2021 7:47 PM in response to Francis Drouillard

APFS Containers cannot grow 'backwards', that is, from higher disk block addresses to lower addresses. If you have a Time Machine Backup, you can erase your whole disk, and restore your TM backup. If you do not have a TM backup, you can create one now.

Your Bootcamp/Windows installation was at lower disk block addresses before you remove Windows. BC Assistant has the same limitation.

See

for reference.

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Answer 4

Mar 27, 2021 6:10 PM in response to Francis Drouillard

Apple requires use of Boot Camp Assistant to remove Boot Camp partitions:

Remove Windows from your Mac using Boot Camp - Apple Support

As is usual with partitions, expect everything to get blown away due to some problem or another with some tool, and accordingly always have backups of everything across all partitions you care about.

Partitions are a technology that unfortunately far too often involves data loss when something goes wrong. And things can and do go wrong.

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Answer 5

Mar 27, 2021 6:59 PM in response to MrHoffman

Thank you for that helpful reply!

All of my data is backed up, both MacOX and Windows 10.

I used Boot Camp Assistant to remove the Boot Camp partition. I then used this Terminal command:

diskutil apfs deletecontainer disk1

Running "diskutil list" shows the output above.

This thread suggests I should delete all the volumes and containers, then repartition, but I'm not sure that will get everything into a single 4TB partition.

I'd like to return to a single container with 2TB for MacOS, then use Boot Camp Assistant to create another container with 2TB for Boot Camp/Windows 10.

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Answer 6

Mar 27, 2021 7:23 PM in response to MrHoffman

Only one internal disk, so I selected "Restore."

I have another thing to try before I wipe everything and start over:

https://apple.stackexchange.com/questions/406962/how-to-make-remove-free-space-and-make-apfs-container-take-it-up/407055#407055

(Hope that's allowed here.)

Thanks again for your timely help and advice!

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Answer 7

Loner T

Level 9

59,513 points

Mar 28, 2021 9:17 AM in response to Francis Drouillard

Do you have a functional Windows up and running? Be aware that the layout you have is non-standard and will cause issues in the future, if you need to Repair Windows. BC Assistant will not properly support the layout that you currently have.

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Answer 8

Mar 29, 2021 1:52 PM in response to Loner T

I have a functional Boot Camp partition that starts to Windows 10. No problems so far.

Boot Camp Assistant created the OSXRESERVE and BOOTCAMP partitions. I don't know why they aren't part of Container 2.

Any advice on how to achieve a proper layout?

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Answer 9

Loner T

Level 9

59,513 points

Mar 29, 2021 5:06 PM in response to Francis Drouillard

Francis Drouillard wrote:

I have a functional Boot Camp partition that starts to Windows 10. No problems so far.

Good.

Boot Camp Assistant created the OSXRESERVE and BOOTCAMP partitions. I don't know why they aren't part of Container 2.

They are separate partitions. APFS volumes cannot be used when installing Windows.

Any advice on how to achieve a proper layout?

My recommendation would be to use Time Machine and backup macOS/erase the whole disk/restore the TM backup and then install Windows.

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Answer 10

Mar 27, 2021 7:18 PM in response to Francis Drouillard

The thread: https://discussions.apple.com/thread/251226595

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Missing 2TB of 4TB SSD?

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