Can I use external boot drive with Apple Silicon Mac?

[krs]

I currently have been running the 2012 Mac Mini with Mojave using an external 1 TB SSD as the boot drive.
The original plan was to install the SSD inside the Mini; as a short term temporay measure (I as pressed for time), I instead installed that SSD into a USB 3 enclosure to use it instead of te internal 500GB spinner in the Mini and then just move the 1 TB SSD inside the Mini when I had more time.
Well, that was over a year ago and I never found the time to install the 1 TB SSD inside the Mini.
So I have been running like this ever since using the external as my main boot drive.
Turns out there is also a benefit in doing this, when I visit my kids who are also on Macs, I can just unplug my external 1 TB external, plug it into one of their MacBooks and I'm good to go during the visit.

Now thinking about moving to an Apple Silicon Mini in 2023, I wonder if I can do the same thing or if Apple prevents me from doing this because of their silicon integration.
Plan is to get an external 2 TB SSD wth a high speed connection to the new Mini (with the smallest SSD), install Ventura (or the next macOS) on it and then use that as my main boot drive.

 

[MacInWin]

It is doable, but you could only boot another Apple Silicon machine with that drive. So the use case of carrying the drive to visit the kids would only work IF they also had AS machines. There are also a lot of other complications with Apple signing, the new "Owner" concept and how security now works in AS machines, but if you, and your kids, are willing to put up with the rather painful process, it is possible.

That said, I would not recommend it as a regular way to business, nor would I spec out a Mini based on that plan. The boot process is entirely different with AS Macs.

You can do some reading here: Booting two Apple silicon Macs from one external disk

And some of these, too:

Search Results for “external boot ” – The Eclectic Light Company

Macs, painting, and more

eclecticlight.co

EDIT: Note the list of actions in the middle of the first article. He booted from the INTERNAL drive first, then changed the boot drive to the EXTERNAL and then booted from the external. And to back that out, you have to boot from the EXTERNAL first and then reset the boot drive to the INTERNAL to get it to boot again from there. So moving to your kids machine you would have to let them boot from the INTERNAL, set the boot to your drive, with it attached, and then boot from your drive. All of the drives need the same version and updates, or things will get complicated. (Even more than now.) And if you forget to reset your kids' machines, they will be stuck with a nasty situation where the boot drive is not there and changing it back to their own internal is non-trivial.

 

[pm-r]

Turns out there is also a benefit in doing this, when I visit my kids who are also on Macs, I can just unplug my external 1 TB external, plug it into one of their MacBooks and I'm good to go during the visit.

I don't see that as any big benefit does you could do the same thing with any old cloned external drive, even a much cheaper spinner, but SSDs probably travel safer and better.

Just a personal comment and you're welcome to disregard it. ;-)




- Patrick
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[krs]

It is doable, but you could only boot another Apple Silicon machine with that drive.

Thanks Jake,
Very informative and great links

 

[krs]

I don't see that as any big benefit does you could do the same thing with any old cloned external drive, even a much cheaper spinner, but SSDs probably travel safer and better.

Patrick,
The benefit over a cloned external is:
a. I can just eject the external drive I normally use as a boot drive, unplug it and I'm ready to go in 10 seconds or less. And the information on that drive is 100% up to date.
With a cloned external, either the data on it is not up to date or it would take me about 3 hours to make an up-to-date clone.
b. On return same thing in reverse - any changes, additions etc I made when visiting will be automatically on the external boot drive. Plug it in to the Mini at home, boot up and I'm exactly where I was at the end of my visit. With a clone I would have to update the internal Mini drive to get all the changes & additions back on the main drive.

But forget about the visiting part, there is also a large financial incentive, a 2 TB external SSD is a lot cheaper than the Apple upgrade cost for a 2 TB internal.
Upgrading an M1 Mini to 2 TB is $C925.- which with tax adds over $C1000 to the price.
I can buy a Crucial 2TB SSD for less than $C200.-

 

[MacInWin]

I can just eject the external drive I normally use as a boot drive, unplug it and I'm ready to go in 10 seconds or less.

Not really. The target Mac will have to be booted at least twice to get going and twice to get back to as it was before you started. So not 10 seconds, but maybe a couple of minutes on each end.

Plug it in to the Mini at home, boot up and I'm exactly where I was at the end of my visit.

Again, it's more than "plug it in and boot." You have to boot from the internal drive first, then set the external as the boot drive and reboot from it to be "exactly where I was at the end of my visit."

A lot has changed in AS/Ventura that makes the use of external drives much more tricky. Don't underestimate the work required to make it happen. It CAN be done, but it's a lot more than plug'n'play.

And although fast, externals drives are much slower than the internal storage, particularly on Apple Silicon. Have a look at this:

Should you pay the high price of a high-speed external SSD?

With a shiny new high-speed Samsung X5 SSD to test, I was looking forward to some real speed. Did it deliver good value for its high price, though?

eclecticlight.co

and

What performance to expect from SSDs

Before deciding on internal and external storage, you need to be realistic about the performance it will achieve. Here are the numbers – and a couple of things we tend to forget about.

eclecticlight.co

In that last article you will see that internal storage speeds are over twice the speed of the fastest external drive. So, maybe the price is worth it for the performance?

 

[krs]

Not really. The target Mac will have to be booted at least twice to get going and twice to get back to as it was before you started. So not 10 seconds, but maybe a couple of minutes on each end.

I guess I didn't make myself clear.

I was describing the way I do this currently, with the 2012 Mini and Mojave and comparing that to Patrick's comment that making a clone and taking that instead of my external boot drive is just as easy.

Trying to do this with an "M" Mac has become pretty cumbersome as you have pointed out.

 

[pm-r]

Again, it's more than "plug it in and boot." You have to boot from the internal drive first, then set the external as the boot drive and reboot from it to be "exactly where I was at the end of my visit."

Thanks Jake, so I gather from this comment that booting and holding the option key to select a boot drive is no longer an option and the feature has been removed from the later Mac OS and Mac models??? Hmmm...???



- Patrick
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[MacInWin]

Not removed, Patrick, relocated. On AS Macs you hold down the power key and it will show the options to boot. You get to Safe Mode through that, too.

But, in Ventura on AS Macs, the FIRST operation of the boot process is done on the internal storage, even with the Power button being held down. And there is a new security feature called "Owner" that has to be set for each drive from which you boot, and which is attached to the Mac itself by the process of boot from internal, set boot drive, boot from external. If that is not followed, the system won't boot from the external because the owner isn't set.

It is part of the new, tighter, security with AS and Ventura. It's not onerous, unless you want to do something like what @krs is attempting to do. He CAN do it, it just not as easy and clearcut as it was before.