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.

First Look Big Sur Feature2
The free space issue has been addressed in a revised macOS Big Sur 11.2.1 update that was released this morning. According to Mr. Macintosh, the new update checks to make sure there is enough available storage space before installation starts.


If you don't have enough free space, the installer will say "There is not enough free space on the selected volume to upgrade the OS," and it will let you know how much additional space is required.

The new update that was released today is available only if you had not previously installed macOS Big Sur 11.2.1.

Related Forum: macOS Big Sur

Popular Stories

iOS 26 Feature

iOS 26.1 to iOS 26.4 Will Add These New Features to Your iPhone

Saturday October 18, 2025 11:00 am PDT by
iOS 26 was released last month, but the software train never stops, and iOS 26.1 beta testing is already underway. So far, iOS 26.1 makes both Apple Intelligence and Live Translation on compatible AirPods available in additional languages, and it includes some other minor changes across the Apple Music, Calendar, Photos, Clock, and Safari apps. More features and changes will follow in future ...
ios 26 1 liquid glass opaque

iOS 26.1 Beta 4 Lets Users Control Liquid Glass Transparency with New Toggle

Monday October 20, 2025 10:57 am PDT by
With the fourth betas of iOS 26.1, iPadOS 26.1, and macOS 26.1, Apple has introduced a new setting that's designed to allow users to customize the look of Liquid Glass. The toggle lets users select from a clear look for Liquid Glass, or a tinted look. Clear is the current Liquid Glass design, which is more transparent and shows the background underneath buttons, bars, and menus, while tinted ...
iphone air thickness

Apple Said to Cut iPhone Air Production Amid Underwhelming Sales

Friday October 17, 2025 8:29 am PDT by
Apple plans to cut production of the iPhone Air amid underwhelming sales performance, Japan's Mizuho Securities believes (via The Elec). The Japanese investment banking and securities firm claims that the iPhone 17 Pro and iPhone 17 Pro Max are seeing higher sales than their predecessors during the same period last year, while the standard iPhone 17 is a major success, performing...
iOS 26

iOS 26.0.2 Update for iPhones Coming Soon

Friday October 17, 2025 7:35 am PDT by
Apple's software engineers continue to internally test iOS 26.0.2, according to MacRumors logs, which have been a reliable indicator of upcoming iOS versions. iOS 26.0.2 will be a minor update that addresses bugs and/or security vulnerabilities, but we do not know any specific details yet. The update will likely be released by the end of next week. Last month, Apple released iOS 26.0.1,...
Apple iPad Pro hero M5

New iPad Pro Has Six Key Upgrades Beyond M5 Chip

Saturday October 18, 2025 10:57 am PDT by
While the new iPad Pro's headline feature is the M5 chip, the device has some other changes, including N1 and C1X chips, faster storage speeds, and more. With the M5 chip, the new iPad Pro has up to a 20% faster CPU and up to a 40% faster GPU compared to the previous model with the M4 chip, according to Geekbench 6 results. Keep in mind that 256GB and 512GB configurations have a 9-core CPU,...
iPhone Siri Glow

Some Apple Employees Have 'Concerns' About iOS 26.4's Revamped Siri

Sunday October 19, 2025 7:39 am PDT by
iOS 26.4 is expected to introduce a revamped version of Siri powered by Apple Intelligence, but not everyone is satisfied with how well it works. In his Power On newsletter today, Bloomberg's Mark Gurman said some of Apple's software engineers have "concerns" about the overhauled Siri's performance. However, he did not provide any specific details about the shortcomings. iOS 26.4 will...
HomePod mini and Apple TV

Apple's Next Rumored Products: New HomePod Mini, Apple TV, and More

Thursday October 16, 2025 9:13 am PDT by
Apple on Wednesday updated the 14-inch MacBook Pro, iPad Pro, and Vision Pro with its next-generation M5 chip, but previous rumors have indicated that the company still plans to announce at least a few additional products before the end of the year. The following Apple products have at one point been rumored to be updated in 2025, although it is unclear if the timeframe for any of them has...
maxresdefault

Here's How the iOS 26.1 Transparency Toggle Changes Liquid Glass

Monday October 20, 2025 1:55 pm PDT by
With the fourth beta of iOS 26.1, Apple added a toggle that makes Liquid Glass more opaque and reduces transparency. We tested the beta to see where the toggle works and what it looks like. Subscribe to the MacRumors YouTube channel for more videos. If you have the latest iOS 26.1 beta, you can go to Settings > Display and Brightness to get to the new option. Tap on Liquid Glass, then...
m4 macbook air blue

M5 MacBook Air Coming Spring 2026 With M5 Mac Studio and Mac Mini in Development

Thursday October 16, 2025 3:57 pm PDT by
Apple plans to launch MacBook Air models equipped with the new M5 chip in spring 2026, according to Bloomberg's Mark Gurman. Apple is also working on M5 Pro and M5 Max MacBook Pro models that will come early in the year. Neither the MacBook Pro models nor the MacBook Air models are expected to get design changes, with Apple focusing on simple chip upgrades. In the case of the MacBook Pro, a m...

Top Rated Comments

HiRez Avatar
61 months ago
Wow, this is a pretty basic thing to miss, with potentially terrible consequences. I mean checking free space before you install, wouldn't that be on the standard checklist since forever?
Score: 36 Votes (Like | Disagree)
NewUsername Avatar
61 months ago
Especially given how many Mac users still have a 128GB SSD.
Score: 25 Votes (Like | Disagree)
ouimetnick Avatar
61 months ago
Why does an OS take up 35GB of space? I remember back when Snow Leopard cam out Apple bragged that it took less space than it's predecessor. Try trimming some of the bloat out of the next macOS release.
Score: 23 Votes (Like | Disagree)
jz0309 Avatar
61 months ago
Apple SW QA still needs way more attention, way too many updates across ...
Score: 21 Votes (Like | Disagree)
Matthew.H Avatar
61 months ago

Choosing storage space during purchasing is the responsibility of the buyer, not the seller. When people cheap out on storage space they are entering at their own risk.
It doesn't help that Apple has frankly been stingy on storage for years. They've only just recently made 256GB the minimum when it should have been the standard base at least 5 years ago.
Score: 20 Votes (Like | Disagree)
now i see it Avatar
61 months ago
Newbie mistake. What's going on over there?
Score: 17 Votes (Like | Disagree)