New iMac Pro unable to backup from Mojave TM

[Daftfunk100]

Hello and thanks in advance if anyone can help. I have just this week bought a new iMac Pro.

What I am trying to do is get a carbon copy of my previous computer on the new iMac Pro.

My previous computer is a late 2013 model iMac running Mojave.

I have been onto Apple support and have been given varying accounts of whether or not this is even possible. One agent told me that it could not be done because the new computer has been shipped with Big Sur. Another agent told me that because this was a 2017 computer that it would be possible.

So far I have tried using migration assistant which didn’t work, followed by utilising disk utility to erase the hard drive and then attempting to restore with Mojave from my backup.

Presently, the computer has finished restoring from that back up, but automatically loaded Internet recovery and demanded an Internet connection.

Can anyone please advise me on how to solve this problem? Many thanks in advance.

 

[Fishrrman]

My pre-written advice on how to do this:
=========================
Fishrrman's "you can do it!" routine for migrating to a new Mac:

If you follow my instructions below, I guarantee a success rate of 98%:
PRINT OUT these instructions and check them off as you go along.

1. BEFORE you do anything else, run a "final" backup on your old Mac. Use an external drive for this. It can be either TM or a cloned backup using CarbonCopyCloner or SuperDuper. I prefer CCC.
I STRONGLY RECOMMEND THAT YOU DO NOT USE TM AS YOUR "MIGRATION EXTERNAL DRIVE". INSTEAD, USE EITHER CCC OR SD. Things will go better this way!
2. Shut down the old Mac and disconnect the external drive
3. Take the new Mac out of the box and set it up on the table. DO NOT PRESS THE POWER ON BUTTON until step 8 (read on). You don't want to begin setup until "the right moment".
4. If you're using an external display, connect the display using the usb-c/VGA adapter/cable that you have
5. Connect the keyboard and mouse if you use them. I STRONGLY SUGGEST that you connect them DIRECTLY to the Mac.
6. If you use a hub, leave it DISCONNECTED for now
7. Connect your backup drive -- use a usb-c adapter if needed.

OK, we're ready-to-go, so let's get goin':
8. Press the power on button for the first time.
9. The new Mac may ask for help "finding" the keyboard, just follow instructions.
10. Begin setup. At the appropriate moment, setup assistant will ask if you wish to migrate from another Mac or drive. YES, you want to do this.
11. "Aim" setup assistant at the external backup. Setup assistant will need a little time to "digest it all". BE PATIENT and give setup assistant the time it needs.
12. You will now see a list of things that can be migrated, such as applications, accounts, settings and data.
13. I suggest that you select ALL of them.
14. Let setup assistant "do its thing". It's going to TAKE A WHILE to move things over. Again, be patient. If you have a lot "of stuff", it will take a lot of time!
15. When done, you should see the login screen. Go ahead and login.
16. Once logged in, things should look pretty much as they looked on your old Mac.
17. You should check all your apps. Some may not run, and may require upgrading.
18. You can set aside the old backup, or ... "repurpose it" to become the backup for the new Mac. I'd keep the old one around for a week or so, at least.

 

[Daftfunk100]

My pre-written advice on how to do this:
=========================
Fishrrman's "you can do it!" routine for migrating to a new Mac:

If you follow my instructions below, I guarantee a success rate of 98%:
PRINT OUT these instructions and check them off as you go along.

1. BEFORE you do anything else, run a "final" backup on your old Mac. Use an external drive for this. It can be either TM or a cloned backup using CarbonCopyCloner or SuperDuper. I prefer CCC.
I STRONGLY RECOMMEND THAT YOU DO NOT USE TM AS YOUR "MIGRATION EXTERNAL DRIVE". INSTEAD, USE EITHER CCC OR SD. Things will go better this way!
2. Shut down the old Mac and disconnect the external drive
3. Take the new Mac out of the box and set it up on the table. DO NOT PRESS THE POWER ON BUTTON until step 8 (read on). You don't want to begin setup until "the right moment".
4. If you're using an external display, connect the display using the usb-c/VGA adapter/cable that you have
5. Connect the keyboard and mouse if you use them. I STRONGLY SUGGEST that you connect them DIRECTLY to the Mac.
6. If you use a hub, leave it DISCONNECTED for now
7. Connect your backup drive -- use a usb-c adapter if needed.

OK, we're ready-to-go, so let's get goin':
8. Press the power on button for the first time.
9. The new Mac may ask for help "finding" the keyboard, just follow instructions.
10. Begin setup. At the appropriate moment, setup assistant will ask if you wish to migrate from another Mac or drive. YES, you want to do this.
11. "Aim" setup assistant at the external backup. Setup assistant will need a little time to "digest it all". BE PATIENT and give setup assistant the time it needs.
12. You will now see a list of things that can be migrated, such as applications, accounts, settings and data.
13. I suggest that you select ALL of them.
14. Let setup assistant "do its thing". It's going to TAKE A WHILE to move things over. Again, be patient. If you have a lot "of stuff", it will take a lot of time!
15. When done, you should see the login screen. Go ahead and login.
16. Once logged in, things should look pretty much as they looked on your old Mac.
17. You should check all your apps. Some may not run, and may require upgrading.
18. You can set aside the old backup, or ... "repurpose it" to become the backup for the new Mac. I'd keep the old one around for a week or so, at least.

Hi thanks but I don’t think you’ve actually read the above. The problem isn’t migrating data. It’s getting the Mac to run off of the OS I want.

 

[Fishrrman]

What OS is on the iMac Pro?
Have you considered that the version of Mojave from your iMac CAN'T BOOT the iMac Pro?

Have you gone to the Startup Security utility on the iMac Pro (I believe it has a "T" chip, right?) and DISABLED all startup security provisions?

 

[DeltaMac]

Disable startup security, as Fishrrman suggests.
Your iMac Pro will boot nicely to Bug Sur, but you want to migrate from another iMac, running Mojave...
"Backgrade" to Mojave on your new iMac Pro:
Connect the old iMac to your new iMac Pro. An ethernet cable would be ideal.
The organization of the volumes for Big Sur is seriously different from that of Mojave, so you will need to remove the existing partitions, and revert to an older partition setup that Mojave will "like"
Get a bootable installer for Mojave, Boot to that installer.
Use Disk Utility to format the internal drive. MacOS Extended (journaled) will work just fine for this. (You will need to format the device, not just a volume or two, so the drive format is something that Mojave can use.) then install Mojave.
The installer will automatically modify the partitions to APFS, in case you might be wondering about using that format.
After the install, choose to migrate from "another computer". Follow the steps to migrate from the old iMac to the new Pro.
And, after the successful transfer of your apps and files - upgrade to Bug Sur (if you want to do that)