Removing Ubuntu from Dual Boot on Mac

[Ishmam-ul-Haque]

Hey, I signed up today and this is my very first post. I hope I'll get help; which I desperately need right now.

I just tried to uninstall and remove ubuntu from dual boot on Mac by just deleting the partition. Basically, I went to the 'Partition' tab and clicked both the partition and removed it. Now when I went to disk utility it seemed odd. It is showing the internal drive is divided into two sections and there are also two external drives namely MacBook Air and Container Disk.....

Did I do anything wrong? If yes, what should I do now it solve it?

 

[treekram]

Something's wrong - it could just be a bug in Disk Utility or something worse.

So what you should see (given the information you've presented) is "APPLE SSD ..." at the top level, and then "Container disk ..." indented below it (not under "External") and then "MacBook Air" below it and indented from "Container disk ...".

I would start a new Time Machine backup right now - if you have a backup disk, I wouldn't use that - just in case. I would also do a different type of backup - so if you use Time Machine, use something like CCC or vice-versa. This means you have to have two free HDD's available or at least free partitions on them that can hold your backup. I wouldn't put the different types of backups on the same disk. If you have to go out and buy an HDD or two, don't turn off the computer - you might even want to tell it not to sleep - and make sure it has AC power.
https://bombich.com/

This may seem over-cautious and a bit of trouble but that's what I would do given what I'm seeing. Once the backups are done you can try restarting and see if things get sorted out or not. If they don't, you can either live with what you have if it's working or re-install using your backup(s).

 

[Ishmam-ul-Haque]

Sadly I restarted my Macbook before seeing your comment. The whole MacOS is gone. All I'm left with is nothing but the ubuntu; which I wanted to uninstall at the very first place. Is it still possible to erase the entire SSD and reinstall macOS ?

 

[treekram]

You need to boot from either another High Sierra disk or a High Sierra installer, typically on a USB flash drive. Before doing the install, run Disk Utility, select the drive ("APPLE SSD ...") and select erase. If that doesn't allow you to erase the entire drive and format it as APFS, in Disk Utility erase the Ubuntu partition first and see if it will allow you to select and erase the entire drive. If that doesn't work, you can wipe out the entire partition table by doing the following:
- Start the Terminal app. If you're using the installer, under Utilities in the menu at the top, select "Terminal".
- Type in: diskutil list (and press the Enter key)
This command will produce a listing. At the very top of the list should be your internal disk and it should be "disk0". You should see your Ubuntu partition and it should be "disk0s3" - the number at the end may be different. If you don't see your Ubuntu partition there with the correct partition size, then I'm misunderstanding what your computer configuration is and you should stop because the next command will wipe out the partition table of this disk.
- Type in: "dd if=/dev/zero of=/dev/disk0 bs=2m count=1" (without the double-quotes)
If you're running from a bootable external drive or it says "Permission denied" or something similar, type in: "sudo dd if=/dev/zero of=/dev/disk0 bs=2m count=1"
This will make the drive look like an uninitialized drive and you should be able to erase the entire drive in the APFS format. You can then quit Terminal and install the OS.