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plasmoyzed Author

Level 1

4 points

SSD Format unsupported or broken

Hello, I have a 2015 MacBook Air, it was running Big Sur but recently I've wanted to downgrade to Catalina because of better app support and battery life, to achieve this I was going to boot into recovery mode, wipe my SSD clean and install macOS Sierra which I would later update to Catalina.

After wiping the drives, back at the main menu in recovery mode I only had the option to download Big Sur so I restarted my Mac in recovery mode, and it started internet recovery and then I ended up in macOS Sierra's recovery mode, I attempted to download macOS Sierra through it but it kept on failing, and so I opened Disk Utility and realized that my drive and it's partitions were in APFS which is not supported by any macOS version older than Mojave. So I tried to erase all the drives and reformat them to macOS Extended Journaled, but that didn't work. I tried First Aid on the drives as well, as many times as I could, and most of the time it failed, after some work arounds none of the drive show up as APFS, they just show as unformatted disk images even though that some partitions claim to be macOS Journaled, I tried to delete the "unformatted" partitions but it doesn't allow me to, but when I scan the disks with First Aid they don't show up as corrupted, except the main disk, which gives out an error code 8. For that I've tried multiple terminal commands recommended online but all of them give out random errors overtime, I've tried commands with sudo in front as well, no luck.

And now every time I restart my Mac into recovery mode it goes into internet recovery downloading recovery mode every time because my SSD is no longer supported.

How do I wipe my drive clean, delete all partitions and reformat it, at this point I don't mind running Big Sur on it as long as I get it to work.

MacBook Air 13″, macOS 11.4

Posted on Aug 1, 2021 9:55 PM

Top-ranking reply

PRP_53

Level 10

91,705 points

Posted on Aug 2, 2021 1:04 AM

1 - How to get old versions of macOS and verify what version this computer Qualifies to install. Make sure to use Only Safari to commence the download as Others may not work..

Above will be needed for actions to do in 2 - below

To perform this action will require booting from a Bootable Installer. This will have to be performed from a Qualifying Computer to run the version of macOS to be made on the Bootable Installer. Example : Bootable Installer of Big Sur would have the done on a computer that Qualifies to run Big Sur.

Once that is done read on for preparing the Destination computer >> Special Notation - works on Intel Based Apple Computers & May on Apple Silicon M1 CPU

Extra Special Notation regarding the Touch ID equipped Apple Computer. About Startup Security Utility and Must Enable from Recovery Mode the ability to boot from External Drive Before Attempting

Shutdown computer and disconnect all external drive Except the newly created Bootable Installer. Restart and immediately hold the OPTION key until the Startup Manager appears and choose the USB Drive. It will present options >> Disk Utilities >> View >> View ALL attached Drives. Choose the Upper Most Drive ( not the volumes indented and list below ). The drive normally is called Apple Media or Apple SSD - that is the drive to Erase and format as APFS with the GUID Partition Map. Once that is done >> backup out of Disk Utilities and choose install macOS. Follow the prompts and it may automatically reboot several time. Upon a final reboot - Setup Assist will present with the newer version of macOS.

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SSD Format unsupported or broken

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