It was reported last week that macOS Big Sur has a serious problem that can lead to data loss when users try to upgrade a Mac to the latest version of the operating system without having enough space available. Apple has finally fixed the problem with a new version of macOS Big Sur 11.2.1, which checks - this time correctly - if the disk has the required space before the upgrade process begins.
The news Mr. Macintosh first reported that many users received an error message when upgrading a Mac to MacOS Big Sur, which did not allow the Mac to boot - and the only solution was to delete some files from the internal drive via Target Disk Mode (which does not work on some models) or wipe the entire disk.
Apple says upgrading to macOS Big Sur for the first time requires at least 35,5 GB available storage space - and this does not includes the macOS Big Sur 13 GB installer. Unfortunately, even if the Poppy If you do not have 35,5 GB of storage available, macOS will try to install the Big Sur update and then may to you lose all your data.
Apple has released its new version macOS Big Sur 11.2.1 (20D75) which no longer allows users to upgrade the operating system without having enough space available. Unfortunately, this does not seem to fix the Macs that got stuck after installation of MacOS Big Sur.
If you have been affected by this issue after trying to install MacOS Big Sur on your Mac, you can follow the detailed guideίs referred to in the blog Mr. Macintosh to recover them archives or at least reset and run your Mac again after installing non-build macOS errors.
Source of information: 9to5mac.com