You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Big Sur will not update

I've had major problems trying to update Big Sur as despite saying it needed 12 kb it then said it needed about 17kb and I had to delete loads of photos and emails to make room. It then said it would take 12 hours to download. It finally got to the end and said there was a security issue and the update couldn't be verified and wanted me to start all over again. I have wasted literally WEEKS trying to get this to update (on my MacBook Air) and don't understand why it needs such an enormous amount of space and why it is proving such an issue. Can anyone help?

MacBook Air 13″, macOS 10.15

Posted on May 11, 2021 1:14 PM

Reply
Question marked as Top-ranking reply

Posted on May 11, 2021 2:10 PM

Please re-read the details from Apple https://support.apple.com/en-ca/HT201475.


If upgrading from macOS Sierra or later, macOS Big Sur requires 35.5GB of available storage to upgrade. If upgrading from an earlier release, macOS Big Sur requires up to 44.5GB of available storage. To upgrade from OS X Mountain Lion, first upgrade to OS X El Capitan, then upgrade to macOS Big Sur.


The Empty Space requirements are to allow the Full Installer of Big Sur ( 12.24 GB 0 to reside on the computer and addition empty space for the Installer to Expand and only then will the Installation will commence


Another Suggest Reading Before attempting the upgrade to Big Sur


Tips How to Upgrade to Big Sur 


There are several points to consider before attempting the upgrade to Big Sur. The most important is Due Diligence on the part of the User and is a Prerequisite for a smooth upgrade.  


The below points should all be consider Before attempting the upgrade.


Point # 1 - There are unconfirmed reports that upgrading from earlier version of macOS will download a " Stub " of Big Sur. This " Stub " maybe about 25 MB is size and is not the Full Installer. If so, run this Application and it should pull down the remainder of Big Sur and commence the Installation


Point # 2 - Are there pre-existing Unresolved Software Issues. They should be resolved prior to upgrading - they may carryover to Big Sur making the system unstable / unusable.


Point # 3 - Are there any AntiVirus, Disk Cleaner, Optimizers, Defrag, VPNs etc installed which should be removed as per Developers Instructions. They are useless, unneeded, cause havoc and interfere with the normal operation of the OS and may even Corrupt the OS requiring a Reinstallation. The Built-in Security of Big Sur is all that is required.


Point # 4 - What are the System Requirements ie: Empty Space Requirements specific to the Big Sur.


Point # 5 - Does the intended computer qualify for the upgrade.


Point # 6 - Are the installed Applications / Extensions compatible with Big Sur. Check with the Developer for compatible Apps / extension or do they offer updates. Same goes for Third Party Drivers for Printer, Scanners etc.


Point # 7 - If upgrading from Mojave and earlier versions of macOS - Remember that Big Sur does not support anything 32 bit. These include Applications, Extensions and Drivers for any devices. There is no workaround.


Point # 8 - Do I have a Rescue Plan In-Place. This comprises having a Time Machine Backup and for addition purposes - two Tested Bootable Clones each to separate external drives. This is insurance incase the upgrades goes sideways


Point # 8  - To upgrade to Big Sur will require a quick, stable and reliable Internet Connection - preferred method is via Ethernet Connection. If not available and using Wifi - move computer as close to the Access Point / Router and disconnect all other devices connected to Wifi. Want the maximum bandwidth for the computer being upgraded to Big Sur.


Good Luck and come back to these Forums if there are questions, concerns or comments.

2 replies
Question marked as Top-ranking reply

May 11, 2021 2:10 PM in response to Beth Martin

Please re-read the details from Apple https://support.apple.com/en-ca/HT201475.


If upgrading from macOS Sierra or later, macOS Big Sur requires 35.5GB of available storage to upgrade. If upgrading from an earlier release, macOS Big Sur requires up to 44.5GB of available storage. To upgrade from OS X Mountain Lion, first upgrade to OS X El Capitan, then upgrade to macOS Big Sur.


The Empty Space requirements are to allow the Full Installer of Big Sur ( 12.24 GB 0 to reside on the computer and addition empty space for the Installer to Expand and only then will the Installation will commence


Another Suggest Reading Before attempting the upgrade to Big Sur


Tips How to Upgrade to Big Sur 


There are several points to consider before attempting the upgrade to Big Sur. The most important is Due Diligence on the part of the User and is a Prerequisite for a smooth upgrade.  


The below points should all be consider Before attempting the upgrade.


Point # 1 - There are unconfirmed reports that upgrading from earlier version of macOS will download a " Stub " of Big Sur. This " Stub " maybe about 25 MB is size and is not the Full Installer. If so, run this Application and it should pull down the remainder of Big Sur and commence the Installation


Point # 2 - Are there pre-existing Unresolved Software Issues. They should be resolved prior to upgrading - they may carryover to Big Sur making the system unstable / unusable.


Point # 3 - Are there any AntiVirus, Disk Cleaner, Optimizers, Defrag, VPNs etc installed which should be removed as per Developers Instructions. They are useless, unneeded, cause havoc and interfere with the normal operation of the OS and may even Corrupt the OS requiring a Reinstallation. The Built-in Security of Big Sur is all that is required.


Point # 4 - What are the System Requirements ie: Empty Space Requirements specific to the Big Sur.


Point # 5 - Does the intended computer qualify for the upgrade.


Point # 6 - Are the installed Applications / Extensions compatible with Big Sur. Check with the Developer for compatible Apps / extension or do they offer updates. Same goes for Third Party Drivers for Printer, Scanners etc.


Point # 7 - If upgrading from Mojave and earlier versions of macOS - Remember that Big Sur does not support anything 32 bit. These include Applications, Extensions and Drivers for any devices. There is no workaround.


Point # 8 - Do I have a Rescue Plan In-Place. This comprises having a Time Machine Backup and for addition purposes - two Tested Bootable Clones each to separate external drives. This is insurance incase the upgrades goes sideways


Point # 8  - To upgrade to Big Sur will require a quick, stable and reliable Internet Connection - preferred method is via Ethernet Connection. If not available and using Wifi - move computer as close to the Access Point / Router and disconnect all other devices connected to Wifi. Want the maximum bandwidth for the computer being upgraded to Big Sur.


Good Luck and come back to these Forums if there are questions, concerns or comments.

May 11, 2021 2:56 PM in response to Beth Martin

Thanks - I am away at present and have no Ethernet connection. Also I've just seen that the Big Sur installer is on my computer twice - both in apps and in "other" so is now taking up more than 24 GB. It won't let me delete either of them.


My MacBook Air keeps telling me every day I need to update to Big Sur but, if I don't have to, I would prefer not as it requires a ridiculous amount of space and is wasting hours of my time.

Big Sur will not update

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.