TimeMachine: restore data after a downgrade

[VitoBotta]

My understanding is that it's no longer possible to restore the full OS and data using TimeMachine after a macOS upgrade, if you decide to downgrade. So for example if you are on Monterey and upgrade to Ventura, and then for some reason you decide to reinstall Monterey, you are not able anymore to restore Monterey as it was before using the TimeMachine backup.

But can you restore the data/documents this way? Or does the TimeMachine backup get upgraded or something like that by the new macOS in such a way that it becomes incompatible with the previous macOS? If I have a TimeMachine backup with Ventura and I downgrade to Monterey with a manual reinstall, can I restore the data and documents with Migration Assistant using that TimeMachine backup?

 

[Fishrrman]

I've never used tm and I don't know how it works.

BUT... I have used cloned backups created with both CarbonCopyCloner and SuperDuper and I know how they work.

With a cloned backup, you CAN manually restore old apps and data. Because you're doing it "manually", it can be tedious, but it CAN be done.

 

[gilby101]

If I have a TimeMachine backup with Ventura and I downgrade to Monterey with a manual reinstall, can I restore the data and documents with Migration Assistant using that TimeMachine backup?

Migration Assistant: You can restore with from a backup which was made with Monterey - choose the most recent Monterey backup. Migration Assistant can't restore from a backup made with Ventura, because it does not understand the format of libraries used by Ventura. Does your TM still have the backups made with Monterey?

Finder: With Finder you can copy document and image files from the most recent Ventura backup to your restored Monterey. But don't try to recover Mail, Photos or Music libraries this way.

I have used cloned backups created with both CarbonCopyCloner

FYI: CCC backups can be restored with Migration Assistant.

 

[Rimmsi]

FYI: CCC backups can be restored with Migration Assistant.

So, if I make a Mojave backup with CCC, I can restore data in HighSierra and below with Migration Assistant?

 

[gilby101]

So, if I make a Mojave backup with CCC, I can restore data in HighSierra and below with Migration Assistant?

No.

Migration Assistant is part of each version of macOS and can be used to restore backups (CCC or TM) made with the same version of macOS or a previous version. But Migration Assistant made with version X can't know anything about future versions.

So if you make a Mojave backup (TM or CCC), you can use it to restore data, apps and settings to a Mojave or more recent macOS. You can't with High Sierra fully restore a backup made with Mojave which is a future (and so unknown to High Sierra) version of macOS.

Any mismatch of macOS versions will cause some issues (e.g. restoring apps which no longer work with a newer macOS). Always best to restore to same version of macOS as made the backup.

If you do need to go backwards, you can (in most cases) still use Finder to copy files from the backup to an older macOS. So Finder in your High Sierra will be able to copy files from a Mojave backup. This works because the HFS+ disk format used by Mojave backups is the known to High Sierra.

 

[VitoBotta]

Migration Assistant: You can restore with from a backup which was made with Monterey - choose the most recent Monterey backup. Migration Assistant can't restore from a backup made with Ventura, because it does not understand the format of libraries used by Ventura. Does your TM still have the backups made with Monterey?

Finder: With Finder you can copy document and image files from the most recent Ventura backup to your restored Monterey. But don't try to recover Mail, Photos or Music libraries this way.


FYI: CCC backups can be restored with Migration Assistant.

Are you sure that e.g. upgrading to Ventura doesn't change ALL the existing backups, and that I can restore from one backup made with Monterey if I downgrade?

 

[gilby101]

Are you sure that e.g. upgrading to Ventura doesn't change ALL the existing backups, and that I can restore from one backup made with Monterey if I downgrade?

Yes. I did this. I had Time Machine backups from both Monterey and Ventura on the same APFS destination. When I went back to Monterey, I chose the most recent Monterey backup. All went well.