M1 mac external boot

Luposian wrote:

I love my new M1 Mac Mini, but I want to be able to boot macOS Big Sur from an external.

Until Apple fixes the flaw with the Startup Security Utility you won't be able to boot from a external.

Apple is aware of this major flaw. If it's not fixed within the next week or so I'll be forced to return my M1 and get a return.

Not being able to boot from a external is a deal breaker.

MyApple8MyPC wrote:

Luposian wrote:

I love my new M1 Mac Mini, but I want to be able to boot macOS Big Sur from an external.

Until Apple fixes the flaw with the Startup Security Utility you won't be able to boot from a external.

Apple is aware of this major flaw. If it's not fixed within the next week or so I'll be forced to return my M1 and get a return.

Not being able to boot from a external is a deal breaker.

If it is going to get fixed, it will likely happen with 11.1 or perhaps a point

release which will encompass many other issues. I really doubt Apple will

release an update just for this one issue as there are still a few others to deal

with.

Also, according to Bombich Software (CCC), there is a utility that still is not

ready for cloning the protected system volume to an external drive for

the M1 which is working on Intel Macs. Perhaps it is all inter related.

If haven't already, call Apple support and have them file a bug ticket,

but make sure you get booted up to a level two or three support

when you make the call. Typically in this sort of matter, level one support

is not really useful.

Also, I think releasing a significant OS change as Big Sur (a lot of underlying/

behind the scenes things have changed dramatically) and totally new hardware

was either a bit too much or was pushed a bit too fast. Given Apple resources

and my experience as an engineer with a "marketing driven" company, I believe

the latter is true.

I have found that the type of drive is also critical. I attempted to make an external boot drive using 6 different SSD's. Some error out like others have noted and some had to be repeated 2-3 times before any success. The only one that worked every time was when I used a WD Black M.2 drive in a TB3 enclosure. The speed may have something to do with it. I also had some luck with a Samsung 840 EVO after trying 2 times before it took.

tbirdvet wrote:

I have found that the type of drive is also critical. I attempted to make an external boot drive using 6 different SSD's. Some error out like others have noted and some had to be repeated 2-3 times before any success. The only one that worked every time was when I used a WD Black M.2 drive in a TB3 enclosure. The speed may have something to do with it. I also had some luck with a Samsung 840 EVO after trying 2 times before it took.

Sounds almost like it is looking for the underlying drive technology, i.e. NVMe, m.2, etc.

when trying to boot and SATA based SSDs are seen as bad when trying to boot external on

M1 machines?

I found this on the Carbon Copy Cloner (CCC) Blog...

"Apple Software Restore doesn't yet support the storage in Apple Silicon Macs

In the current shipping version of macOS Big Sur (11.0.1), Apple's

ASR utility cannot replicate the startup disk in an M1-based Mac.

Attempting to do so results in an error:

'Apple System Restore Tool': Source volume format not yet supported in this version of macOS

Apple is aware of the problem and is working towards resolving it for

a future update to macOS. CCC 5.1.23 will automatically perform Data

Volume backups on M1 Macs and avoid any attempts to copy a System volume

on those Macs. When Apple posts an update to macOS that resolves the

ASR problem, we'll post an update to CCC that adds back support for

copying the System volume on these Macs."

This is the closest to an "answer" (more like an explaination) that I have found, for the problem I am having... hopefully it's resolved in 11.1, which is now (today) showing up as available for install on my M1 Mac Mini.

FWIW, I updated to 11.1 and now the previously created external boot drive

is now showing up in the boot manager when entering Recovery and

can change the security to reduced without getting errors. However,

it wasn't bootable because of some other error, like because it was

created with the 11.0.1. To late today to try and start the process

again, so that task is for tomorrow. There could still be hope

that you don't need 1 of 3 of 4 SSDs made in the world that

will work.

Yeah, "updating" is never a good tactic, when dealing with issues like this. A clean format/install is really the best way. I learned this when I was using MacOS X 10.3 (Panther). But I have the time/interest to give it a shot and see what happens. Thanks for the info!

No joy in Mudville yet.

While the external drive now appears as a boot selection, booting it kicks

me into Boot Recovery which pops a dialog asking for my admin password

to verify the disk. After which, it says it can't verify the disk.

So, seems at least one step forward, but a baby step. I hate to have

to totally rely on Time Machine as I have had one experience where

it rendered itself useless (fortunately had the externally bootable system/clone

drive at the time to completely recover).

As tbirdvet noted, was successful with a couple drives but I hesitate

buying a drive just to find out it won't external boot. Then again,

having an extra drive around may not be a bad thing.

woodmeister50 wrote:

I hate to have to totally rely on Time Machine as I have had one experience where

it rendered itself useless (fortunately had the externally bootable system/clone

drive at the time to completely recover).

I too, have had bad experiences with Time Machine. That's why I also use CCC for backups.

I have several bootable drives. None work with the M1.

Jeffdoehring wrote:

I don't see why it wouldn't work unless the external drive does not have Big Sur. Anything below will not work on a M1

If you follow the entire thread, you will see many that cannot get Big Sur

to boot on an external drive with an M1 machine.

Trebleet. Purchased on Amazon. $129.99. Not cheap but is very fast when connected to the TB3 port. By the way I tried using my WD Black M2 drive in a USB-C enclosure which of course is slower than the TB3 and it would not complete the installation so speed or port compatibility may be an issue.

tbirdvet wrote:

Trebleet. Purchased on Amazon. $129.99. Not cheap but is very fast when connected to the TB3 port. By the way I tried using my WD Black M2 drive in a USB-C enclosure which of course is slower than the TB3 and it would not complete the installation so speed or port compatibility may be an issue.

Thank you so much.

I noticed that OWC has a new TB3 enclosure that is

~2/3 that cost (surprisingly). I may call or fire off an email to see

if they have tested it for booting on M1 Macs.

Just for info:

https://eshop.macsales.com/shop/envoy-express/thunderbolt-3

I noticed it as I have been checking daily for the availability

for their new TB3 hub, which should be soon if one believes

the ad. Powers a host (60 W) and gives 3 TB3 ports.

tbirdvet wrote:

By the way I tried using my WD Black M2 drive in a USB-C enclosure which of course is slower than the TB3 and it would not complete the installation so speed or port compatibility may be an issue.

There are some that swear they are booting into the M1 with USB enclosures.

woodmeister50 wrote:

I noticed it as I have been checking daily for the availability

for their new TB3 hub, which should be soon if one believes

the ad. Powers a host (60 W) and gives 3 TB3 ports.

I saw that hub the other day and it looks really nice. If I don't end up returning this M1 (because of the non-booting external drive issue) then I will probably get two of them. That would give you 6 TB3 ports.

Well, truth be told, I made an interesting discovery... I bought a Memorex 128GB USB 3.0 thumb drive from Target and tried installing Big Sur 11.1 to it and amazingly, it worked! Kinda. :-D It stuck a bunch of more stuff in the folders (instead of all but System being empty), but when all was said and done, it got stuck into a "boot loop" (white Apple logo with progress bar), where it would go so far and then restart and do the same thing. After shutting it down, it got stuck in that "mode" even with the USB stick removed. I booted into Recovery mode, ran "First Aid" on all the internal SSD drives/partititions and then specifically selected "Macintosh HD" as the Startup disk and rebotted. That seemed to work, to get it back to normal.

But given the result was significantly different, it makes me wonder... would attaching the 500GB USB-C drive via the USB-A adapter make it work, since it's a faster drive and the USB-A ports seem to work differently than the Thunderbolt 3 ports.

Another thought was that, I had the 128GB USB drive attached via the a passive (non-powered) 3.0 hub and not plugged directly into the USB 3.1 ports on the M1 Mac Mini. Could that have impacted the outcome?