Bigsur dmg downgrade gone wrong

[DazTazKafraz]

Hi all, new here, could really use some help…
I’m currently using a 2017 256G 13inch MacBook Pro, and I upgraded to Monterey right after its release (a very dumb decision in hindsight). Aftering playing around with the new features, I decided to downgrade back to Bigsur because of app compatibility issues that were unlikely to be solved in the near future.

I followed a Youtube (YT) tutorial and got a thumb drive with the os, but didn’t use Time Machine (TM) for the backup as I did not have the external drive space for that(cuz that would require me to format my 2T drive that contained stuff I had no where else to relocated ). Instead, I used the byte-to-byte functionality of DiskDrill to create a dmg file, and I then saved it to my external drive.

The downgrade process went smoothly until I realized that this dmg file that I saved can not be recognized by Migrant assistant, which meant that I had to manually dissect the file’s content of my user data (files, apps, preferences, and etc) to Monterey. This was rather simple to do as I just had to copy the user and application folder to my “new” disk, but major problems began to emerge after I restarted from security boot to reset user disk permissions (I used [diskutil resetUserPermissions] with the response of most but some of the permissions were resetted, the home directory is among those that didn’t.):

• User login screen had a monochrome black background
• upon my first login it prompted me that my previous keychain was not accessible
• some of the keys are disabled (not the physical keyboard as I hooked up an external one that also did not work)
• Only some of my user preferences were migrated, including wallpapers and gesture settings, but not things like how the finder settings and desktop organizations, Those returned to vanilla settings. Omnifocus retained its task data but lost its user preferences. This is a trend that is mostly consistent with other apps like smooze or pdfpenpro (this is my biggest grievance really)

Is there anyway to smoothly transition with a dmg, currently in heavy lockdown so storage devices won’t be coming in the near future, a TM version of this won’t be likely.

Huge thanks in advance!!!

The other options would just be to restore back to my original state with Monterey, but its a last resort now because of all the efforts I have already put forth.

 

[Fishrrman]

"didn’t use Time Machine (TM) for the backup as I did not have the external drive space for that(cuz that would require me to format my 2T drive that contained stuff I had no where else to relocated ). Instead, I used the byte-to-byte functionality of DiskDrill to create a dmg file, and I then saved it to my external drive."

In "old speak", that's what's known as "being too clever by half".

What I would recommend:

1. Get an external drive and "restore" the disk image to that.
Is the restored drive "a copy of" the internal drive as it was before?

2. Erase the internal drive on the MBP and do a clean install of the OS.

3. Begin initial setup. See if setup assistant can find and migrate your data from the external drive, including:
- account(s)
- applications
- data
- settings

This may work (then again, it might NOT work since you are attempting to migrate from "newer" to "older").

If it DOES NOT work, then you will have to "rebuild" the drive manually.
I'd suggest you move applications first, checking them one-by-one.
Then, you can move data.
BUT --
You will have to take steps to avoid permissions problems.

This can be done by connecting the external drive (NOT the .dmg), then doing a "get info" on the drive icon, click the lock at the bottom, put a checkmark into "ignore ownership on this volume" (sharing and permissions).

Now you can copy stuff from the external drive, and the items you copy should "come under the ownership" of the new account on the internal drive.

You have A LOT OF WORK in front of you.

And you DO need to buy another drive to get your files OUT OF "dmg" and into "regular finder format"...

 

[BigBlur]

If you can't get a second drive, you could use Disk Utility to create a partition on your existing one. If done correctly, it should just shrink your existing partition without losing data, and create a new/empty one with it's own filesystem. That will make it appear/mount as its own disk...and you could do what Fishrrman suggested, or it could be used as a Time Machine disk.

Then when you're all done, delete the partition and extend the main one to cover the whole disk again. Or keep it for backup purposes.

 

[DazTazKafraz]

Thank you for replying!

Is the restored drive "a copy of" the internal drive as it was before?

It should be the exact copy of the one before. When I mount the dmg. file to my current os (the fresh install of bigsur), I can access all of the files, so I think it should be a copy of the entire internal disk.
My question is about the restoration process, which I assume is done through disk utility in recovery mode.
What do I do when the system prompts me the following when I try to use Images>scan image for restore
Scanning "APFS physical store disk0s2.dmg" for restore.
can't open "/Volumes/EDrive/Stuff/Backup/MacOS/APFS physical store
disk0s2.dmg" read/write
Operation failed with status-1: Undefined error: 0
Operation failed...

Do I convert the drive into a compressed format using images>convert; if so, what specific settings do I use?

 

[DazTazKafraz]

If you can't get a second drive, you could use Disk Utility to create a partition on your existing one. If done correctly, it should just shrink your existing partition without losing data, and create a new/empty one with it's own filesystem. That will make it appear/mount as its own disk...and you could do what Fishrrman suggested, or it could be used as a Time Machine disk.

Then when you're all done, delete the partition and extend the main one to cover the whole disk again. Or keep it for backup purposes.

Thank you!
I'll try this, but not sure if I have enough space for that since I almost filled up my entire internal drive previously.

That will make it appear/mount as its own disk...and you could do what Fishrrman suggested, or it could be used as a Time Machine disk.

Will the TM backup be the same or larger than my actual drive content, which is about 210G? Weirdly enough, when I try to use About this mac to see my current storage, I get this:

I estimate that after pulling over my user data and some of the applications over from the mounted image for make-do purposes, I have around 90G left out of my 210G disk space. Will this be enough?