For years I have booted my 2012 Mac Mini computer from a 1TB external HD. Now that I have plunged into the M4 Mac mini how can I install Sequoia on this external HD. My attempts through the recovery process won't install for me. I know there is a big gap in age of computers but there must be a way.
Mac mini, macOS 10.15
The Mac mini M4 supports booting into an OS from an external hard drive, however, Catalina is not supported by the Mac mini M4 due to its new Apple Silicon architecture.
Use more than one version of macOS on Mac - Apple Support
if you need to access data from your external drive with Catalina on it, I would be possible. As soon as you plug in your external drive after booting up the M4 mini to Seqoia, you should see the Catalina drive appear on the desktop. If you don’t see it on the desktop, click on Finder, and it should appear in the side bar.
Basically reformat your external drive using ExFAT or APFS. you can do that with the Disk Utility on Mac OS.
Then download the Sequioa MacOS installer from the App Store.
Run the installer.
Choose the external hard drive as the install destination.
Complete the installation.
Restart your Mac mini and hold the option key when you hear the startup chime. It’ll ask you which drive to boot from.
if you’d like to permanently boot from the external drive, you can set that in
Apple menu > System Settings > General > Startup Disk
Select the external drive as you startup disk here.
I know some reported problems installing Sequoia to an external drive. Personally I just cloned the Sequoia install from the internal drive. That I know works.
At the moment I am coping all the data off the external HD so if need be I can then erase and install Sequoia. Worst case I hope this works. Just kinda surprised booting into recovery wouldn't simply install over the older OS unless there is some technical thing in the background preventing this.
Finished coping my data to another external drive. Booted into the recovery mode and erased the drive I want to use, installed Sequoia so when its finished I'll move the data back and start re installing apps. It will be a slower process but I do have the time. Thanks for all who read and or replied.
You can't boot Catalina on an M4 Mac mini.
You also can't boot Sequoia on a 2012 Mac mini.
Yes, I want to install Sequoia on the external HD that has Catalina on
You could erase the drive and clone Sequoia on it using SuperDuper! or Carbon Copy Cloner. You can clone it for free using SuperDuper!.
Install Sequoia on top of Catalina
