How can I revert from BigSur to Catalina

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Level 1

8 points

How can I revert from BigSur to Catalina

I love Big Sur, it is quite the change, but my MacBook Air 13" is not happy especially when I need to use it for work. I am not trying anything intensive, but it is very slow now to execute the computational models that it never had problems with before. Also the fan is consistently running now, and I am very concerned that the hardware is just not going to hold up.

I don't want to have to convert this to a Linux machine, so I would like to revert back to Catalina so that I can keep the performance and reliability and most importantly the Mac OS. The guide for Big Sur does not show reverting options, if it is in there I could not find it.

Thank you in advance for your help.

Mark

MacBook Air 13″, macOS 11.3

Posted on May 26, 2021 6:31 AM

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Answer 1

PRP_53

Level 10

91,747 points

Jun 4, 2021 9:56 AM in response to irishmhw

Jumping in here on the Bootable Media part. Must mention if going this route - implies will Format the Entire Drive and all is lost. Also, if this computer has the Touch ID - before doing anything MUST Read this now About Startup Security Utility and enable booting from External Drive Before moving forwards.

Need to perform this on a Qualifying Catalina Apple Computer - How to create a bootable installer for macOS on reliable USB Drive - Thumb Drive with minimum of 16 GB Space. Once the Catalina is downloaded and in the Applications folder run the supplied appropriate Apple Script in Terminal.

That done - shutdown the computer and disconnect all external drives except the Bootable Installer. Restart and immediately hold the Option key until the Boot Manage appears and choose the USB Installer. It will present much like Recovery Mode and get into Disk Utilities >> View >> View All attached Drives. Navigate to Upper Most Drive ( not volumes indented below ) usually called Apple Media or Apple SSD. Erase the Drive >> give it a name and use APFS Format and GUID Partition Map. That done back out of Disk Utilities and choose Install macOS. Follow the prompts and there will several Automatic Reboots along the way until the final reboot and Setup Assist of the OS will be presented.

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Answer 2

PRP_53

Level 10

91,747 points

May 26, 2021 6:32 AM in response to irishmhw

Revert your Mac to a previous macOS version

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Answer 3

irishmhw Author

Level 1

8 points

Jun 3, 2021 7:38 AM in response to PRP_53

Thank you for your response and I wish it was that easy.

I am in recovery, selected the time machine back up to use, chose the destination (only hard drive there), and entered one of the user passwords. Now All I see is a different volume calculation for the HDD, "Go Back", and "Unlock".

"Go Back" works, "Unlock" does not. It just stays on that screen, it has been 1 hour of the same screen. Do I need to delete the second user account on the computer before progressing or is there some other magic spell I need :=)

Thank you for any help you can give.

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Answer 4

Eau Rouge

Level 8

42,602 points

Jun 4, 2021 6:15 AM in response to irishmhw

To downgrade to an older OS you need to erase the Disk on your mac.

Boot to your Recovery HD, select Disk Utility press Continue.

Click on View on the menubar and select Show All Devices.

Highlight the Disk not any of the indented Volumes.

Click Erase.

Give the Disk a name.

Format: APFS.

Scheme: GUID Partition Map.

Click Erase.

Now reinstall Catalina. You did make a bootable USB installer beforehand, yeah, good.

Then restore only your personal data from your users folders from the back up you made before

erasing your disk.

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Answer 5

irishmhw Author

Level 1

8 points

Jun 4, 2021 9:15 AM in response to Eau Rouge

So I can't restore to Catalina from the Time Machine backup? Or is this another option.

No, I don't have a bootable USB Installer for Mac. I have tried but failed multiple times with Mac bootable media. Should I try and remove the other accounts and then go through Time Machine? How do I get bootable media for Catalina?

I have tried a similar approach with Windows machines in the past with disastrous results which is where I first started and continue using Linux on them. Essentially what seems simple never works well for me, I am the Murphy's Law of technology.

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Answer 6

irishmhw Author

Level 1

8 points

Jun 14, 2021 7:28 PM in response to PRP_53

So first off thank you for the help. But a few things.

I need to have a computer with Catalina on it to be able to downgrade to Catalina? What?

So, then what is the point of Time Machine? I use third party programs for all of my work save for MS garbage I must use. I just have a bash script to install all of those, so the original selling point of Time Machine is why I bother since I am obsessive about backups. Time Machine was supposed to be able to allow for easy restoring back to a previous (before mess up) time point and allow for that fresh start feeling. So, no more, or never?

I'll try and make the media on this Big Sur box, but I don't have a Catalina computer, friends don't either .... I guess it's Linux -- assuming the experience will be like the "easy process" for Windows that never worked and made me first use Linux.

Thank you again both, I do appreciate your time.

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Answer 7

PRP_53

Level 10

91,747 points

Jun 3, 2021 7:41 AM in response to irishmhw

The Account being Restore is an Admin Account ? The second account is Guest, Standard, Admin ?

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Answer 8

irishmhw Author

Level 1

8 points

Jun 3, 2021 8:15 AM in response to PRP_53

Thank you,

I am restoring to an Admin Account, the other is Admin too and there is a Guest account that is swtiched off (thus doesn't show up in the restore window).

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Answer 9

PRP_53

Level 10

91,747 points

Jun 4, 2021 4:01 AM in response to irishmhw

Honestly and never experienced such as situation before. So, am not totally sure what the next correctly answer is! Will research more and see if can find the answer and get back to you.

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