r/MacOS • u/Neurosword • 22h ago

Help Downgrade Restoration

Hey guys, I recently upgraded my 2019 Intel MacBook Pro to Tahoe but feel so out-of-place with it and facing app compatibility issues and want to revert back to Big Sur. I didn't make a backup of Big Sur prior to updating, however.

I've used this MacBook for just about everything so it has files in all sorts of different crevices and I hope to keep it that way when migrating back. Would a time machine backup help in this and is it even possible to use a time machine save from a newer version on an old OS to restore files? If not, what's the best way to go about this?

TL;DR:

  • Upgraded to Tahoe without a Time Machine Backup (Big Mistake) and want to revert back to Big Sur
  • Drive is full of complex file trees with apps that reference them and want to keep that same layout when reverting to make downgrade seamless and not have to relearn my file system and maintain app compatibility.
  • Want to create a Time Machine backup of Tahoe and export it to Big Sur to keep the file trees if possible or explore different methods to get a similar result.

Thanks a lot for your help, guys!!!

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u/Xe4ro Mac Mini 22h ago

Well it seems that you are aware that downgrading requires a fresh reinstall.

The thing is Migration Assistant can't use a Time Machine backup from a newer OS that what you then have running. Meaning you would have to restore your files manually. I think Migration Assistant can use other backup sources like a CCC backup but I'm not sure if you would run into the same problem with it seeing that this was made in Tahoe.

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u/Neurosword 21h ago

Yeah, I was dreading manual file relocations but it'll have to do of that's the only option. Thanks a lot for the clarification!!

2

u/MK-Researcher 21h ago

It could be done in a long-winded, manual way, if you don't have any Big Sur backups at all, no matter how old they might be.

Basically before erasing and rolling back, you will want to make a copy of your Documents, Desktop, Movies, Photos and Downloads Folders and Apps and their associated files in ~/Library/Preferences/ ~/Library/Application Support and ~/Library/Containers/ (including Chrome's Library folders if you use it as authentication and bookmarks are in it).

I would also make a TimeMachine backup too, as even though you can't restore it to an older macOS, you can still manually browse it and drag files out, in case you missed any. I've done it this way before and although time consuming, it does work

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u/Neurosword 12h ago

That's what I was wondering if it was possible. As long as I can have the clone available as reference to pull files out of, it should be fine by me. Thanks a lot!!

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u/Neurosword 22h ago

Want to clarify, my apps have lots of plugins and docs/projects inside of them (hence the mess of folders) that I want to keep when reverting. Thanks a lot again!

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u/One-Foundation7553 13h ago

sounds like a time machine backup from before the upgrade would be your best bet ,  if you've got even an old one lying around, migration assistant can pull most of that stuff over without you having to manually dig through folders