MacRumors published a story that Apple has released a revised macOS Big Sur 11.2.1 update to properly checks free available space to prevent installation errors.
Revised macOS Big Sur 11.2.1 Update Properly Checks Free Available Space to Prevent Installation Errors
When upgrading to macOS Big Sur, there was an error that would cause issues if there wasn't enough storage space available. Unfortunately, the update was not checking if there was enough free space before the installation started, which could lead to data loss. The free space issue has been addressed in a revised macOS Big Sur 11.2.1 update that was released this morning.
