Repairing my Mojave MBP

[B-bob]

I have kept my MBP on Mojave as I need to run software that is not compatible beyond it.

I am now sending my MBP in for repairs (SSD and front case replacements) and the agreement Apple had me sign says...
"Apple may install system software updates that will prevent your Apple product from reverting to an earlier version of the system software."

I have both a time machine backup and a CCC backup. If they install Big Sur on my computer, why would I not be able to wipe the drive and revert to either of these backups?

 

[barbu]

They will almost certainly not do a major version update to your machine.

 

[appltech]

If they will be installing a fresh SSD, I'm almost sure, they will install the latest OS.
But yes, if your backups are in order, you should be able to erase whatever they install, and restore your current OS and everything.

 

[Fishrrman]

The CarbonCopyCloner backup is "the key".

No matter what OS they send it back with, you can just boot from your cloned backup, erase the internal drive and then "re-clone" your backup BACK TO the internal drive, and it should be "as it was before".

That's the beauty of keeping a cloned backup.

 

[B-bob]

Thank you, guys. That's what I anticipated. I was just thrown by their comment that a system software update could "prevent [my] Apple product from reverting to an earlier version of the system software."

 

[B-bob]

Actually, I have a new related question now...

As I said, the Apple Store is replacing the SSD in my MBP. I wanted to use a CCC backup of my MBP so I could restore it to the new SSD after it is installed. I just noted however that CCC is warning me that "the APFS helper partition couldn't be mounted." I understand the backup it created cannot boot a computer, but I don't necessarily need it to. Can I still use this backup to restore my data to the new SSD after it is installed? Or will the computer also be unbootable afterwards?

 

[Fishrrman]

When you get the computer back, this is what I'd do:
1. Boot from the cloned backup
2. Open disk utility
3. Go to the view menu and choose "show all devices"
4. On the left, click the "topmost" line that represents the physical drive inside the MacBook
5. ERASE it to "APFS with GUID partition format".
6. Quit disk utility and open CCC
7. RE-CLONE the backup BACK TO the internal drive. If CCC asks if you wish to clone the recovery partition as well, YES, do this too.

That's what I'd try first.

 

[B-bob]

Thanks. That is what I had hoped to do. The problem is CCC was not able to create an AFPS Helper Partition so my backup is not bootable.

When you get the computer back, this is what I'd do:
1. Boot from the cloned backup
2. Open disk utility
3. Go to the view menu and choose "show all devices"
4. On the left, click the "topmost" line that represents the physical drive inside the MacBook
5. ERASE it to "APFS with GUID partition format".
6. Quit disk utility and open CCC
7. RE-CLONE the backup BACK TO the internal drive. If CCC asks if you wish to clone the recovery partition as well, YES, do this too.

That's what I'd try first.

 

[Fishrrman]

"The problem is CCC was not able to create an AFPS Helper Partition so my backup is not bootable."

OK, then I'd try this:
Boot the MBP to a SPECIAL VERSION of internet recovery:
Command-option-shift-R

This will install the original OS that shipped with the MBP you have.
Something "earlier than" Catalina, I reckon.

You'll need your wifi password.
The internet utilities will take a while to load.

When the utilities are loaded:
a. Open disk utility
b. Go to the view menu and choose "show all devices".
(if there is no "view" menu, don't worry about it, go to step c)
c. Select the topmost line on the left that represents the internal drive
d. Erase it to Mac OS extended with journaling enabled, GUID partition format.
If that doesn't work, repeat steps a-d and this time try APFS with GUID partition format. ONE of these will work.
e. When done, close disk utility and open the OS installer.
f. Install a copy of the OS onto the internal drive.
When done, begin the setup process. When setup assistant asks if you wish to migrate data from another drive, connect the CCC backup and give it time to "digest things".
g. Setup assistant will present you with a list of stuff to migrate -- I'd just "do it all".
h. Let setup assistant do its thing. When done, you should see the login screen.

I don't know which version of the OS this will result in.
You didn't tell us WHICH YEAR your MBP was made and WHICH OS originally came on it.

But... if it's an OS version earlier than Mojave, you may now be able to upgrade TO Mojave.

When you get there, TURN OFF FOREVER the option to "automatically keep my computer up to date".

In the future, when you do a CCC backup, it might be worth "testing" it by booting from it.
Just to be sure...

 

[B-bob]

"The problem is CCC was not able to create an AFPS Helper Partition so my backup is not bootable."

OK, then I'd try this:
Boot the MBP to a SPECIAL VERSION of internet recovery:
Command-option-shift-R

This will install the original OS that shipped with the MBP you have.
Something "earlier than" Catalina, I reckon.

You'll need your wifi password.
The internet utilities will take a while to load.

When the utilities are loaded:
a. Open disk utility
b. Go to the view menu and choose "show all devices".
(if there is no "view" menu, don't worry about it, go to step c)
c. Select the topmost line on the left that represents the internal drive
d. Erase it to Mac OS extended with journaling enabled, GUID partition format.
If that doesn't work, repeat steps a-d and this time try APFS with GUID partition format. ONE of these will work.
e. When done, close disk utility and open the OS installer.
f. Install a copy of the OS onto the internal drive.
When done, begin the setup process. When setup assistant asks if you wish to migrate data from another drive, connect the CCC backup and give it time to "digest things".
g. Setup assistant will present you with a list of stuff to migrate -- I'd just "do it all".
h. Let setup assistant do its thing. When done, you should see the login screen.

I don't know which version of the OS this will result in.
You didn't tell us WHICH YEAR your MBP was made and WHICH OS originally came on it.

But... if it's an OS version earlier than Mojave, you may now be able to upgrade TO Mojave.

When you get there, TURN OFF FOREVER the option to "automatically keep my computer up to date".

In the future, when you do a CCC backup, it might be worth "testing" it by booting from it.
Just to be sure...

All done. The guide above helped tremendously. Thank you. My only complaint is that File Vault got turned off in the process. I guess I will have to reenable that later.

Do you know if the restore process validates that the data was copied accurately? I understand CCC checks for corrupt files when it makes the backup (depending on the settings), but I don't know if MacOS does the same when it restores from that backup.