Can't restore from Time Machine backup

[zzziggy]

Guys, I need your help!

I downgraded my MB Air 2017 from Monterey to Mojave. I have a backup on a portable ssd disc, but Migration Assistant doesn't see it.

I noticed that the format from my other machine's backups is different - it's not a disc image, but simply a folder with System, Users, etc sub-folders inside.

Is there really a way for me to restore it, or am I screwed?

 

[barbu]

If your backup is a disc image, it is not a Time Machine backup. So that will explain why Migration assistance doesn't see it. Can you see the files in the image? How did you create image? Is it bootable, etc...

 

[Fishrrman]

OP, you're not being clear here.

Was your "backup" created with a backup application, such as time machine, CarbonCopyCloner, SuperDuper, or something else?

OR... is it just folders and files that you "copied yourself" to the external drive?

Take a screenshot of the folder/file hierarchy on the backup drive and post it here so we can see it.

If it's "just folders and files copied by hand", then you'll have to "re-construct" the drive "by hand". That means, copying things over a little at a time, until you have it pretty much as it was before.

That's what it sounds like you have.
If that's the case, you can't use Migration Assistant.

You're going to have to get a pencil and paper (to keep track of things).

Also, you need to do this (to overcome permissions problems):
a. connect the backup drive
b. let its icon mount on the desktop
c. click ONE time on the icon to select it
d. bring up the "get info" box (you can type command-i)
e. at the bottom of get info, click the lock and enter your password (the one you are using with the newly-installed Mojave)
f. put a checkmark into "ignore ownership on this volume" (in sharing and permissions)
g. close get info.

Now you can copy files from the backup and they will "come under the ownership" of your account on the Mojave OS.
If you don't do this, you could end up in "permissions hell".

Special info about copying things in the home folder.
You CANNOT COPY the "top level" of folders in your home folder into the new home folder.
That is... you can't copy the folders named "movies", "music", "pictures", "documents", etc.

HOWEVER -- you CAN copy files (and folders) that are INSIDE of these folders.
So you have to go through them one-at-a-time and move things carefully.

Good luck.

 

[gilby101]

I downgraded my MB Air 2017 from Monterey to Mojave.

Even if you have used Time Machine for your backup, downgrades can be tricky. The only downgrade which is certain to work with Migration Assistant is using a TM backup created with the target version. In your case, a backup made when you were last running Mojave and not by a more recent macOS.

You are going to need to manually copy files from the backup (whatever it is) to Mojave. Fingers crossed that Mojave recognises an external disk which may have been formatted with a macOS three versions ahead. There is no promise of backward compatibility.

(Just adding to what @Fishrrman has already said).

 

[madrich]

You are going to need to manually copy files from the backup (whatever it is) to Mojave. Fingers crossed that Mojave recognises an external disk which may have been formatted with a macOS three versions ahead. There is no promise of backward compatibility.

Agreed. If your downgrade to macOS Mojave does not recognize the external disk data then you probably need to reinstall Monterey.