Cannot reset my MacBook Air
I’m trying to factory reset my MacBook air. I tried to update my computer but it is stuck
MacBook Air 13″, macOS 10.15
Question marked as
TheLittles wrote:
“This can be dangerous if done wrong. The macOS Base System image will appear in Disk Utility and users might try to erase it - even though they should not. (It contains the running Recovery system.)”
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“Dangerous”?
How can that be dangerous? I guess it’s risky business, if you’re not so familiar with doing so. You’re simply erasing the hard drive, and then by proceeding with the reinstall after you formatting it.
It completely depends on how the reformat is done.
The tried and tested method of erasing an Intel-based Mac (except for Fusion Drives) is to always target the top-level internal drive, and then erase/reformat that in Disk Utility. That method in particular completely reconfigures the drive from scratch, adds exactly one container and empty volume for macOS to use (plus the hidden EFI partition), and guarantees that nothing else remains - even if the user added their own volumes or partitions. No matter what the starting state is, the end state is always consistent and correct.
(As far as I'm aware, Apple Silicon Macs can be erased in the same way starting in macOS Big Sur 11.2 and later - I think. Disk Utility is smart enough to preserve the hidden system critical containers and just removes everything else. It also makes a new empty container and volume for macOS to be installed into.)
In contrast, there's several ways that the phrase "delete all the volumes" could be taken, and it could result in the user not being able to reinstall macOS.
- Delete all of the APFS volumes that appear in Disk Utility, by selecting each one and clicking the minus sign at the top. This could work for simple/default scenarios to remove the old data, but there wouldn't be a new empty volume for macOS to be installed in afterwards - thus making the macOS installer fail. Also, extra partitions or APFS containers previously made would survive.
- The macOS Base System volume also appears in Disk Utility, but not under the internal drive - it's part of a disk image instead. Nonetheless, users could try to delete it, not realizing it's critical. Luckily Disk Utility doesn't allow that volume to be erased or deleted.
- Delete all of the partitions on disk. If Disk Utility (the app) allowed users to do this, the disk wouldn't be usable until a partition was added or the disk was reformatted. Luckily, the only way to truly delete all partitions in Disk Utility is to erase the top-level drive itself, which recreates the correct default partitions.
In short, always erase/reformat the top-level internal drive (APPLE SSD) in Disk Utility to guarantee that everything gets wiped and that the correct volumes are recreated. If you have a Fusion Drive, run "diskutil resetFusion" in Terminal in macOS Recovery instead.
