How to use external drive as main drive on a MAC Mini

You can clone your current Mac Mini boot drive to an external SSD as follows:

I successfully cloned my Mac Mini M4 boot drive to an external SSD.  I had contacted CCC to ask them if I was using CCC correctly in trying to clone my drive but kept getting errors.  

Their reply and instructions for cloning the drive are as follows: 

Apple's APFS replication utility is consistently failing, it's not going to be able complete this task. I wish I had any insight at all into what kind of corruption it's finding, how serious it is, etc, but Apple's tool just doesn't provide that level of detail.

So, on to plan B:

1. Boot into Recovery Mode

2. Erase the external disk in Disk Utility

3. Install macOS on the external disk

4. When the installation has completed, accept the offer to migrate data from your original source disk

Best wishes,

Rob

Bombich Software, Inc.

I followed the directions to the letter and got a bootable clone of my internal SSD.   Then I can use CCC to update the clone user data from my internal SSD. 

However, there could be a problem if a later version of Sequoia or the next system required a firmware upgrade. That happened to me and caused my Mini M4 to crash with the dreaded flashing orange/amber light. Had to take the Mini into the Apple Genius Bar to get it cleared and reset with the proper firmware. Then had to use Migration Assistant to migrate my user data from the Time Machine backup.

So it will work by you'd have to update or upgrade your internal boot drive first each time an update or upgrade was available.

This will help: Use an external SSD as your startup disk … - Apple Community

iCloud storage is associated with the Apple Account and will be available when the same Apple Account is logged in.

This is the simplest method I have been using on my 2 minis for the past 2 years.

1. Install the macOS on the external drive after which it will ask you to set up the computer just like you do with any new Mac . . . name, location, time & date, wifi etc.
2. Open system settings and make sure you have selected the external as the startup disk.

That's it!

Those last 2 paragraphs are very interesting!

A few weeks ago I tried to boot back into the internal SSD and my mini crashed/froze.

I switched off and then tried to reboot but then the flashing orange SOS signal started.

Eventually I cured it by holding down the power key to start in recovery mode, ran First Aid on the disks and then restarted selecting the internal SSD and all was well.

Previously I had switched boot drives on several occasions and was puzzled by the catastrophic results this time.

I had probably updated the OS a week earlier.

After reading your final comments I am now wondering whether my problem was due to updating the external but not the internal?

Having said that, on the previous successful attempts at swapping between drives I have never had a problem even though the internal has always been several grades below the external.

I had the same issue with the orange flashing light when I attempted to boot from my external drive and system crashed. I kept holding down the power button to get to recovery and after I attempted 4-5 times it finally booted to recovery and I restarted from there on the internal and all was OK. I then redid my external using recovery for all to be fine again. I little nerve racking.

I had a near disaster experience when upgrading Sequoia on an external drive to an OS I was not allowed to talk about. I ended up with a computer that was in a boot loop that in a minute would stop and show the "www.apple.com/restore" . The computer would not boot into internal or external and would not even boot into recovery. The attempted to do a Restore on the internal to macOS Sequoia failed over and over and even took it to an AASP and they could not get it restored. Ended up buying a new Mac. On a whim and last ditch attempt to bring the old Mac back to life I did a restore to the OS I'm not allowed to talk about and that brought it back to life.

So, to me, it seems that external booting which was a no brainer for years has become somewhat risky and the fact that many functions of macOS are no longer being supported on external drives (Apple Intelligence, Wallet, etc.) makes me wonder how much longer this will be an option other than perhaps an installer.

What on earth is happening?

Somehow my words are being replaced by asterisks. I was able to correct one but no matter how hard I try to write "am" I get asterisks!

It's done it again . . . what's going on?

Just testing! I want to see if the forum will accept the first person in the present tense.

I am testing.

I'm testing to confirm your ** issue.

I also have a 2T external drive.

Is it a solid-state drive or a mechanical hard drive? If mechanical and set as the boot volume, your performance will be glacial at best.

tbirdvet wrote:

I'm testing to confirm your ** issue.

For those following along at home, some words including ɢᴇᴛ and ᴀᴍ are being erroneously filtered.

The Apple hosts are aware.

I just noticed the "**" phenomenon as well with my previous post and the words "censored?" were "was" and "**". The second is a with m. How absurd is this?