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Lynne326

macrumors regular
Original poster
Jun 25, 2011
128
12
Hi everyone!

I have a Mac Mini and I foolishly did an upgrade of the OSX to Catalina. I hate it, it's SUPER slow. I have read how to downgrade, but can't get anything to work. I don't really need any of the stuff on the Mini since it's a second computer, so I'd like to just wipe it and a clone of an old internal hd from my Macbook, which I have from when I replaced it with an SSD drive. It's in an enclosure,

Questions:

1) I don't know the OSX version that my Mini came with, is there a way to find out? OR,
2) Would the clone install it's OSX version along with the everything else?
3) Assuming it's compatible with the Mini, what are the steps to overwrite the current Mini HD with a clone of the old Macbook internal hd?

Thank you for the help!!

Lynne
 

steve217

macrumors 6502a
Nov 11, 2011
533
792
NC
Hi everyone!

I have a Mac Mini and I foolishly did an upgrade of the OSX to Catalina. I hate it, it's SUPER slow. I have read how to downgrade, but can't get anything to work. I don't really need any of the stuff on the Mini since it's a second computer, so I'd like to just wipe it and a clone of an old internal hd from my Macbook, which I have from when I replaced it with an SSD drive. It's in an enclosure,

Questions:

1) I don't know the OSX version that my Mini came with, is there a way to find out? OR,
2) Would the clone install it's OSX version along with the everything else?
3) Assuming it's compatible with the Mini, what are the steps to overwrite the current Mini HD with a clone of the old Macbook internal hd?

Thank you for the help!!

Lynne
From the “About this Mac” dialog, what does the model number say?
 

IngerMan

macrumors 68020
Feb 21, 2011
2,005
902
Michigan
First you should edit your post and delete your serial number. It’s kinda like giving your social security number.

It could be claimed in different ways that it is lost stolen etc.

Website I got the below How to from.




How to downgrade to the OS that shipped on your Mac
While we are talking about Recovery, you might like to try the following method of downgrading your Mac to the version of macOS it shipped with. (It didn't actually work for us when we tried, perhaps because our internet connection wasn't good enough, but it should work in theory!)

This has been a feature in macOS Recovery since macOS Sierra 10.12.4, and it should reinstall whatever version of the macOS your Mac shipped with, according to Apple.

Apple explains that you should shut down your Mac and then as you restart press Shift-Option/Alt-Command-R together (this is not easy one-handed!).

Here are the steps Apple describes:

  1. Start up your Mac pressing Shift-Option/Alt-Command-R.
  2. Once you see the macOS Utilities screen choose the Reinstall macOS option.
    Recovery Mode Mac
  3. Click Continue and follow the on-screen instructions.
  4. Select your startup disk and click Install.
  5. Your Mac will restart once the installation is complete.
Note: This will wipe your Mac.
 

Lynne326

macrumors regular
Original poster
Jun 25, 2011
128
12
Thank you for the tip about my serial number, Ingerman, I didn't realize that. Ok, I'll try what you sent here. Thank you!!!
 

Lynne326

macrumors regular
Original poster
Jun 25, 2011
128
12
Ingerman, on #4 of the instructions, I don't have a startup disk. Is there a work around?
 

IngerMan

macrumors 68020
Feb 21, 2011
2,005
902
Michigan
You do have a startup disk. It’s your hard drive in the mini, you just have to pick it. That will be the only choice unless you have external drives attached.

Your start up disk is what your using now with the current operating system to start up. Most likely your current HD in the Mini.
 
Last edited:

Lynne326

macrumors regular
Original poster
Jun 25, 2011
128
12
Hi Ingerman, I finally got around to trying your suggestion but I'm not having any success. I keep getting this error:

"an error occurred while preparing the installation. try running this application again installing macOS Sierra on disk macintosh HD- Data".

I've tried multiple times.

Any suggestions?

Thanks!
 

Fishrrman

macrumors Penryn
Feb 20, 2009
28,346
12,461
OP:

You have a bootable copy of the OS on the external drive, is that correct?

Have you tried BOOTING THE MINI from the external drive, just to see if it will do it?

1. Power down ALL THE WAY OFF
2. Connect the external drive to the Mini
3. Press the power on button and IMMEDIATELY hold down the option key and KEEP HOLDING IT DOWN
4. Does the startup manager appear?
5. Do you see the external drive there?
6. If so, click on it with the pointer and hit return.

What happens next?
If the Mini boots, go to "about this Mac" and see if you really are booted from the external.

Then... report back to us.
 

IngerMan

macrumors 68020
Feb 21, 2011
2,005
902
Michigan
I think the problem might be your HD is now APFS format. I picked up on that when you wrote "HD-Data"

Some one that has more practice with this will hopefully chime in. But I think you will have to goto "Disk Utility" vs "Reinstall MacOS" And format your APFS HD to Mac OS Extended

File system formats available in Disk Utility on Mac​

Disk Utility on Mac supports several file system formats:

  • Apple File System (APFS): The file system used by macOS 10.13 or later.
  • Mac OS Extended: The file system used by macOS 10.12 or earlier.
 

Lynne326

macrumors regular
Original poster
Jun 25, 2011
128
12
I was thinking that I might need to do the disk utility also. I'll wait and see if anyone else has any thoughts on it.

Thanks so much!
 

IowaLynn

macrumors 68020
Feb 22, 2015
2,145
588
You can make a bootable cone for startup and those are always handy. Sounded like you have one.

Catalina was bonkers for me, old junk, out of date stuff left hanging around from years of updates and NOT doing a clean yearly install or clone setup. Clean system plus restore some of the data needed.

Seems like the Home Library is where Apple is keeping stuff and it keeps growing. You can force ~/Library to show on side bar in Finder. Might even copy / move it to another disk and delete it.

Catalina on 128GB (256 prefer) ad 8GB can run okay. For me my 2015 MacBook has seen it is time and Apple took it in trade ($250) for new 16/512GB Mini that can't wait. But you is more a backup computer, doesn't need to be faster, and could act as a media server for the house.

HFS+ is more suitable for HDD on-SSD while APFS is aimed at SSD. But there are issues. CCC or SuperDuper! are A1 for cloning backups that can be booted from. I think you can install MacOS to external drive as well as internal drive as the destination. Disk drives use to need to be reformatted to map out weak/bad areas, even SSD's can have pages that need to be mapped out. And cause trouble. One reason I try to keep drives 40% free space.
 

brianmowrey

macrumors 6502
Oct 5, 2020
419
133
I keep getting this error:

"an error occurred while preparing the installation. try running this application again installing macOS Sierra on disk macintosh HD- Data".

You will want to reformat your internal drive to remove the Catalina format. It's very easy. In the (original OS) Recovery Mode, open Disk Utility. Make sure you are set to view All Devices (you should be by default in the Sierra version of Disk Utility.) Select the drive itself, not any of the nested containers or volumes, and Erase. Use Mac OS Journaled.

This image is from Catalina Disk Utility, but I'm selecting my HDD which is currently on High Sierra. It's just to demonstrate what setting you want for HD drives / any OS before High Sierra.

Screen Shot 2020-10-27 at 9.31.14.png


Once that is done, run First Aid on the drive and the nested volume, to make sure everything passes. Then quit Disk Utility. Connect to your wifi in the menu bar, if you have not already. Then open Install Mac OS X Sierra. (*edit: or boot to the external drive by restarting and holding Option, and start the cloning process).

Older OS's sometimes take a while to download, depending on where you are, because they are on slower servers. If you find that Sierra is taking ages to download, or just don't want to use internet recovery, there's another option. You can also cherry-pick what OS you want to roll back to by creating a bootable installer. Apple provides instructions for El Capitan, High Sierra, and Mojave here.
 
Last edited:

Lynne326

macrumors regular
Original poster
Jun 25, 2011
128
12
Thank you both for the detailed information, I appreciate it. Some of it is a little over my head, but this gets me started to figure it out. :)
 
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Lynne326

macrumors regular
Original poster
Jun 25, 2011
128
12
Brian, in disk utility I see "AppleAPFSMedia". From there should I choose "Macintosh HD", "Macintosh HD- Data", or "APPLE HDD HTS541010A9E662 MEDIA" ?
 

brianmowrey

macrumors 6502
Oct 5, 2020
419
133
It is not. The default name Apple uses for the main boot drive is “HD”, but you can name it whatever you want.
 

Lynne326

macrumors regular
Original poster
Jun 25, 2011
128
12
Yes, I chose Disk Utility under MacOS Utilities where I was previously choosing "reinstall MacOS"
 

brianmowrey

macrumors 6502
Oct 5, 2020
419
133
K. Next step is run First Aid on the drive itself and all nested volumes. If it seems like First Aid fixed something, you can try erasing HDD again. If First Aid finds something it cannot fix, you likely need a new drive.
 
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