Missing 500gb of space after deleting Bootcamp

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Missing 500gb of space after deleting Bootcamp

I'll try to keep this short, but essentially I wanted to add space to my bootcamp partition using a wizard tool on Windows 10. Originally, I had 1TB of space on my iMac and I gave Bootcamp like 300gb (something like that I don't remember this was a year ago), so I decided to add space to it since the instructions seemed pretty straightforward (wrong). Once I did that successfully and added space to the Windows Bootcamp partition, I couldn't boot up my Mac OS X anymore at all, possibly because I removed too much space from that partition? After reinstalling Mac OS via Recovery Mode, I then couldn't boot up my Bootcamp and instantly got hit with a blue wall.

I messed around and decided the best course of action is to factory reset my iMac, starting with attempting to delete my Bootcamp partition entirely, followed by deleting my Mac OS too; a full reset. I started with deleting the whole Bootcamp partition so I can re-install it after the factory reset, but it wasn't letting me at all (I deleted it, said operation successful, but the partition still appeared and couldn't be booted). I then used the terminal diskutil command and after a while managed to finally delete my Bootcamp partition. I don't see it on my diskutil list anymore... good.

Then I deleted the Apple partition and fully re-installed Mac OS again. Everything looks smooth and operates fine on Apple.

Now I want to reinstall Bootcamp, however in Disk Utility it only says I have 500gb of space for my Mac when originally I have 1TB of space. I don't want to split my HDD 50/50 between 500gb for Bootcamp, my plan was doing a 50/50 split with the 1TB my computer came with.

Here is the screenshot of my diskutil list: (It even shows the 1TB)

And here are the screenshots of my Disk Utility:

Everywhere I look it mentions to go to Recovery Mode and either re-install Mac OS (I've done this twice already) or go to Disk Utility in Recovery Mode and partition the main disk/add the unallocated space to it (which also doesn't work)

It's as if 500gb ceased to exist in my computer, when I click partition, it asks to partition from the 500gb as if that's all the space there is. Did I accidentally permanently delete 500gb of space from my Mac? Help is appreciated and in case you're wondering, all of my important data and info is backed up in an external HDD so no worries. I'd love if I could factory reset everything and re-install everything from scratch and allocate 500gb of 1TB to Bootcamp and keep the the 500gb for my Mac OS. How can I fix this?

I have a 2020 iMac 27-inch 5K Retina running macOS Catalina

iMac 27″ 5K, macOS 10.13

Posted on Jun 23, 2022 11:10 AM

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Answer 1

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HWTech

Level 9

60,554 points

Jun 25, 2022 2:20 PM in response to nicopancho787

While booted from the macOS installer (USB or Internet Recovery Mode) use Disk Utility to erase the whole physical SSD as GUID partition and APFS (top option). If you are not given the whole 1TB, then you will need to try the following option to destroy the partition table located at the beginning of the SSD using the following Terminal commands. I highly recommend disconnecting all external devices just to be safe as it will make things easier and there will be less risk of making a mistake which could accidentally destroy data.

Usually when booted from the macOS installer, the internal physical drive will usually have a drive identifier of "disk0". Make sure to verify the physical drive is indeed "disk0". All of my commands will use "diskX" instead so make sure to replace "diskX" in all of the commands with the correct drive identifier for your physical internal drive. You can use Disk Utility to do this (make sure to click "View" within Disk Utility and select "Show all Devices" so that the physical drive appears on the left pane of Disk Utility. You can also get the drive identifier using the command line.

Get drive identifier for internal physical drive:

diskutil  list  internal  physical

Unmount all volumes on the selected drive identified as "diskX" in the command (make sure to replace "diskX" with the correct drive identifier for your physical internal drive):

diskutil  unmountDisk  diskX

Write zeroes to the beginning of the physical internal drive identified as "diskX" (again use the correct identifier in place of "diskX"):

sudo  dd  if=/dev/zero  of=/dev/diskX  bs=100m  count=10

This command will prompt you for your admin password. Nothing will appear on the screen as you type the password. Press the "Return" key to submit the password. If these command all complete without error, then you should be able to properly use Disk Utility to erase the whole physical drive as GUID partition and APFS (top option). If this still does not work, then we may need to check some other things.

FYI, once you have multiple partitions and operating systems set up on a drive, you really should never modify those partitions or you are likely to break one or both operating systems. Tools made for Windows should never be used on a Mac. Windows tools are made only for Windows only systems. The rule I was taught which has served me well is to remember to only use the tools included in the host OS to work on the drive of the host OS even if those other tools are capable of potentially working with that OS. Only the OS itself really knows all the subtleties of its system and third party tools are usually going to fall short at some point. With mixed OS systems, things should never be readjusted unless you fully remove the one OS (usually only the later added OS unless you really know what you are doing and are willing to risk the main OS).

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Missing 500gb of space after deleting Bootcamp

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