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Free Space in Physical Disk unable to be merged back to the main disk.

Introduction

Hello there. I use a MacBook Air (13-inch, 2017) with macOS High Sierra currently running on Version 10.13.4 . CPU is an i5 and 8GB of RAM. The SSD I use contains about 251 GB of storage space, but only 197GB of that is allocated to the main Disk (Macintosh HD), with the remaining 53GB becoming "Free Space". When I run diskutil list I get the following output:

/dev/disk0 (internal, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *251.0 GB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_APFS Container disk1 197.0 GB disk0s2

/dev/disk1 (synthesized):
#: TYPE NAME SIZE IDENTIFIER
0: APFS Container Scheme - +197.0 GB disk1
Physical Store disk0s2
1: APFS Volume Macintosh HD 110.0 GB disk1s1
2: APFS Volume Preboot 22.2 MB disk1s2
3: APFS Volume Recovery 519.1 MB disk1s3
4: APFS Volume VM 2.1 GB disk1s4
5: APFS Volume Youtube Volumes 556.9 MB disk1s5

/dev/disk2 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: CCCOMA_X64FRE_EN-US... +5.8 GB disk2

As you can see, there's some notable storage space locked behind "Free Space". The main speculation behind that is that when Uninstalling Bootcamp through BCA, it crashed and could not reallocate the space back into the main drive, causing it to become free space.


Failure of Disk Utility

At first, I thought that maybe resizing the partition through Disk Utility would be possible. So I opened up DU in Both the Normal working environment and recovery mode. I ran a first aid but there was nothing wrong with the disk. So I tried to resize the partitions on the disk. The first problem I encountered is that when I tried to drag the circular slider to resize the Partition, DU Immediately crashes. Like the application just quits. In Recovery Mode, it just jumps back to the Utility page. No idea why.

I then tried to select the Free Space and clicked the "-" Button to remove it. There are 2 situations that I've encountered: One is that the new Macintosh HD Partition now becomes about 350GB of storage With the original Free Space multiplied by 3 times. When I clicked Apply, it told me that The allocated space to the Macintosh HD was larger than the allowed partition space (250 GB). So that failed obviously.

Another situation was that The free space was fully removed and Macintosh HD showed 251 GB of space. This was the correct situation so I clicked Apply. However, no matter how many times I've tried this method, It told me something like this:

Running operation 1 of 1: Remove “--”…
An internal error has occurred and the disk for one of the specified operations could not be found. This may be a temporary issue, try again.
Operation failed…

I've browsed the web for errors like these and all said that using BCA or Terminal was the correct way to solve the error. So I proceeded with BCA.


Failure using Bootcamp Assistant

Bootcamp Assistant did not recognize that I had previously had a copy of windows installed on the laptop before, so I could not recover the lost free space with its Uninstallation mechanism. So I decided to Install Bootcamp Windows again, to try to force that free space into BC Windows and Uninstall it to get all the disk space back.

At first, BCA told me that there was not enough space to be partitioned (40 GB). There was a bug with time machine local snapshots so I removed them and thoroughly backed up my laptop once again. After providing it with the ISO file, It told me this:

Your disk could not be partitioned
An error occurred while partitioning the disk. Please run Disk Utility to check and fix the error.

So apparently, both BCA and DU failed to solve the problem.

I'm a bit trash on console commands, so I did not try that at first. I was afraid that I would accidentally kill the drive if I deleted the wrong partitions as I have no clue on how to analyze them. Please give me some advice below so I can solve this problem that has been annoying me since earlier this year. I have also made a backup on a portable hard disk with Timemachine, so if the entire disk has to be wiped and reinstalled, I can just restore the Entire system back into the hard drive. However, will this cause the Original Partition to be restored as well, or will the free space just disappear? Thanks!

MacBook Air

Posted on Jul 4, 2021 9:01 PM

Reply
Question marked as Top-ranking reply

Posted on Jul 5, 2021 4:05 PM

Hello, Teinc3.


First things first. Please apply any macOS updates that are available for your computer. The latest update for High Sierra should bring the version to 10.13.6. Use Apple menu  > About This Mac > Software Update...


Second, the APFS format works differently than the traditional HFS+ Mac formatted drives. APF volumes dynamically share all of the space that is available within a container. Each volume will grow as the needs of the files within require. So, theoretically, you should never have to resize an APFS volume if the OS is doing its job properly. There are options -reserves and quotas- available for managing an APFS volume size, but they can only be accessed when you create a new volume.


In this case, because neither DU nor BCA can access the free space on the drive, I think it would be best if you made sure your Time Machine backup is current, then boot into recovery mode (⌘R), use Disk Utility to erase the drive and format it APFS with GUID partition map and finally reinstall the macOS on the drive.

How to reinstall macOS - Apple Support: https://support.apple.com/en-us/HT204904


After theOS is reinstalled, plug in your TM backup and either restart and work through the Setup Assistant and migrate your data back onto the internal drive. Or finish the set up without the backup drive attached and then afterward plug it in and use Migration Assistant.

Restore items backed up with Time Machine on Mac -Apple Support:

https://support.apple.com/guide/mac-help/restore-items-backed-up-with-time-machine-mh11422/10.13/mac/10.13


Set up your mac - Apple Support:

https://support.apple.com/guide/macbook-pro/set-up-apd831707cb3/2019/mac/10.14.5


Move your content to a new Mac - Apple Support:

https://support.apple.com/en-us/HT204350


Similar questions

4 replies
Question marked as Top-ranking reply

Jul 5, 2021 4:05 PM in response to Teinc3

Hello, Teinc3.


First things first. Please apply any macOS updates that are available for your computer. The latest update for High Sierra should bring the version to 10.13.6. Use Apple menu  > About This Mac > Software Update...


Second, the APFS format works differently than the traditional HFS+ Mac formatted drives. APF volumes dynamically share all of the space that is available within a container. Each volume will grow as the needs of the files within require. So, theoretically, you should never have to resize an APFS volume if the OS is doing its job properly. There are options -reserves and quotas- available for managing an APFS volume size, but they can only be accessed when you create a new volume.


In this case, because neither DU nor BCA can access the free space on the drive, I think it would be best if you made sure your Time Machine backup is current, then boot into recovery mode (⌘R), use Disk Utility to erase the drive and format it APFS with GUID partition map and finally reinstall the macOS on the drive.

How to reinstall macOS - Apple Support: https://support.apple.com/en-us/HT204904


After theOS is reinstalled, plug in your TM backup and either restart and work through the Setup Assistant and migrate your data back onto the internal drive. Or finish the set up without the backup drive attached and then afterward plug it in and use Migration Assistant.

Restore items backed up with Time Machine on Mac -Apple Support:

https://support.apple.com/guide/mac-help/restore-items-backed-up-with-time-machine-mh11422/10.13/mac/10.13


Set up your mac - Apple Support:

https://support.apple.com/guide/macbook-pro/set-up-apd831707cb3/2019/mac/10.14.5


Move your content to a new Mac - Apple Support:

https://support.apple.com/en-us/HT204350


Jul 5, 2021 3:15 PM in response to Teinc3

Good afternoon Teinc3,


Welcome to the Apple Support Communities!


It sounds like you are having issues with the partitions on your MacBook Air, and we'd like to help.


Based on everything you've tried, it might be helpful for you to speak with an AppleCare technical advisor about this issue. Click the link below, choose the phone number for your region from the list, and call when it is convenient.


Contact Apple for support and service


Take care.

Jul 5, 2021 9:48 PM in response to D.I. Johnson

Thanks! I've just erased the physical drive and all the free space finally went back into the new Macintosh HD Disk.

So now there's no free space and the problem is fully solved.

I used migration assistant to restore all my data from my backup successfully, and everything including my keychains are working well and fine.

Free Space in Physical Disk unable to be merged back to the main disk.

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