Monday, February 8, 2021

Check Free Space Before Updating to Big Sur

Mr. Macintosh:

The macOS Big Sur upgrade is not checking for available HD space. The upgrade will run out of space and fail. Even worse, if FV2 encryption is enabled, you will be locked out of your data!


This isn’t the first time I’ve reported on update issues that could cause data loss. The 2019-001 Security update issue was close to this one. If you installed the 2019-001 Security Update and the Mac was encrypted, the user could be locked out.


If you have a T2 Mac, you will not be able to get into macOS recovery because your password will not work. This problem further complicates recovery efforts.


I feel for anyone who had this issue over the past 3 months. Almost every single situation ended up with an erase and reinstall losing all data.

The problem only seems to affect updating to Big Sur, not updating from macOS 11.1 to 11.2.


Update (2021-02-19): Adam Engst:

If you or someone you know ends up in the Boot Recovery Assistant loop after attempting to upgrade to Big Sur, there are various workarounds, depending on whether or not your Mac has a T2 chip and whether or not you have enabled FileVault.

Filipe Espósito:

Apple has finally fixed the issue with a new build of macOS Big Sur 11.2.1, which properly checks if the disk has the required space before starting the upgrade process.

5 Comments RSS · Twitter

Great job, Craig Federighi! The Mac OS has seen a steady decline after Snow Leopard (macOS/OS X's high point) when you joined. Keep it up!

This happened to me when updating one of my test systems to a newer beta of 10.15 back in July of 2019. The installer got part of the way through, then failed due to running out of disk space, leaving that system in an unbootable state.

Given it was an early beta of Catalina and the system was just a test system that I didn't rely on, I shrugged it off, and then sent a bug report to Apple using Feedback Assistant, suggesting that they thoroughly check to make sure there's sufficient free space before starting an installation. Naturally that bug report got no response from Apple, as seems to be typical these days. (At least their previous bug tracker would let me know if my bug report was a duplicate, and occasionally an Apple dev would actually ask me for more information!)

I'm now rather dismayed but not at all surprised to find that the problem has not been fixed over a year and a half later. I miss the days of Apple valuing the quality of their software.

@Martin Looks That era was when Scott Forstall was in charge. Software direction under Craig Federighi is just not -good enough.

Forstall was never in charge of Mac. Snow Leopard was Bertrand Serlet's, whose last release was Lion, a bad release that was the beginning of the end.

>Snow Leopard was Bertrand Serlet's, whose last release was Lion, a bad release that was the beginning of the end.

It was clearly a rush job, and felt unforced. I wonder how much of that was precisely due to leadership changes.

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