Big Sur on external SSD

[Lnds500]

So I have upgraded my Catalina installation on my external T5 SSD to Big Sur and now the installation on the drive is not recognized in startup manager.

It appears in the recovery Startup Disk utility but it gives me an error if I try to select it.

Any help?

 

[Areyouwinningson?]

What error does it give exactly?

if you have a Mac with T2 chip, Apple has given some steps which can be found below:

https://support.apple.com/en-in/HT208198

Exapanding on that:

Open Startup Security Utility​

1. Turn on your Mac, then press and hold Command (⌘)-R immediately after you see the Apple logo. Your Mac starts up from macOS Recovery.
2. When you're asked to select a user you know the password for, select the user, click Next, then enter their administrator password.
3. When you see the macOS utilities window, choose Utilities > Startup Security Utility from the menu bar.
4. When you're asked to authenticate, click Enter macOS Password, then choose an administrator account and enter its password.

Change External Boot settings​

Use this feature to control whether your Mac can start up from an external hard drive, thumb drive, or other external media. The default and most secure setting is ”Disallow booting from external media.” When this setting is selected, your Mac can't be made to start up from any external media. Attempting to do so will cause your Mac to display a message that your security settings do not allow this Mac to use an external startup disk.
To allow your Mac to use an external startup disk:

1. Open Startup Security Utility.
2. Select ”Allow booting from external media.”
   Your Mac doesn't support booting from network volumes, whether or not you allow booting from external media.
3. If you want to select an external startup disk before restarting your Mac, quit Startup Security Utility, then choose Apple menu  > Startup Disk.

Note:
I would leave the Secure Boot option as it is and only make changes to external boot settings.

 

[Lnds500]

It doesn't have the T2 chip, it's a 2014 mini.

"The bless tool was unable to set the current boot disk" is the error that I am getting.

 

[Areyouwinningson?]

Which partition is the SSD set on?.

 

[Lnds500]

Which partition is the SSD set on?.

Not sure I understand.

It's an external formatted into APFS with the GUID partition Map option if that helps

 

[Areyouwinningson?]

Can you try swapping/reconnecting out with some extra/same pair of cables. Sometimes the cable are fault or loosely connected.

Also please try resetting the NVRAM

You did mention that the upgrade process went fine. So less reason to believe the boot volume might be corrupted.

 

[Lnds500]

Can you try swapping/reconnecting out with some extra/same pair of cables. Sometimes the cable are fault or loosely connected.

Also please try resetting the NVRAM

You did mention that the upgrade process went fine. So less reason to believe the boot volume might be corrupted.

I reset the NVRAM, nothing changed.

Also something weird is going on. When I start the startup manager 50% of the time the bootable USB and the external SSD don't show up. If I shut it down and restart it again they do.

I ended up erasing the SSD hoping that a clean installation will fix things. I reinstalled Big Sur and now it doesn't start either, I get a boot loop.

 

[Lnds500]

So after erasing the SSD I installed Catalina again.

It booted fine.

I downloaded Big Sur again and installed it anew to the SSD.

Now when I select it on startup manager, it looks like it's loading, then goes to black, starts loading again and boots into recovery.

I am really tired of this ****. I've been at it for 10 hours!

Here's a picture of the Disk Utility.

On Catalina I had the SSD with one container and 2 parts (macOS SSD/macOS Data)

Now I have 3 parts (?)

And the bootable section is gone from startup as well

 

[ab225]

So after erasing the SSD I installed Catalina again.

It booted fine.

I downloaded Big Sur again and installed it anew to the SSD.

Now when I select it on startup manager, it looks like it's loading, then goes to black, starts loading again and boots into recovery.

I am really tired of this ****. I've been at it for 10 hours!

Here's a picture of the Disk Utility.

On Catalina I had the SSD with one container and 2 parts (macOS SSD/macOS Data)

Now I have 3 parts (?)

And the bootable section is gone from startup as well

I can't explain this part of the issue, but I have been booting off an external SSD for while (before I swap out the internal drive) and recently updated Catalina to Big Sur with no problem. One consistent issue I've had however is if I have another thumb drive plugged in at the same time my boot drive doesn't show up as an option on the boot screen. Have you tried making sure it's the only drive plugged in?

 

[Lnds500]

I can't explain this part of the issue, but I have been booting off an external SSD for while (before I swap out the internal drive) and recently updated Catalina to Big Sur with no problem. One consistent issue I've had however is if I have another thumb drive plugged in at the same time my boot drive doesn't show up as an option on the boot screen. Have you tried making sure it's the only drive plugged in?

I had 2 USB devices, the bootable install media and the external SSD.


EDIT: **** IT BOOTED!!! OMG I don't know if that was the problem but thanks a lot!

Now to restore my files. I will post if I burn the house down

 

[ab225]

Glad to hear it might've helped!

Trust me, I had been scratching my head for a while before realising unplugging another disk made a difference

 

[kevbradfield]

Glad to hear it might've helped!

Trust me, I had been scratching my head for a while before realising unplugging another disk made a difference

Hey!

I was wondering if maybe you could help me out. I have a very similar issue to the original poster of this thread but mine isn't an issue of extra external disks being plugged in.

The macOS Big Sur update seems to have downloaded onto my External Hard Drive and now I can't access the original files I had on it? It used to be a silver icon, named 'G-Drive', and now it's yellow/orange and called 'Update'.

I'm just trying to figure out how I can access the original files I had because they're clearly still on there. When I click "get info" their is +/- GB660 in use and the files that pop-up don't even amount to more than +/- GB60..?

Any help would be greatly appreciated!

 

[ab225]

Hey!

I was wondering if maybe you could help me out. I have a very similar issue to the original poster of this thread but mine isn't an issue of extra external disks being plugged in.

The macOS Big Sur update seems to have downloaded onto my External Hard Drive and now I can't access the original files I had on it? It used to be a silver icon, named 'G-Drive', and now it's yellow/orange and called 'Update'.

I'm just trying to figure out how I can access the original files I had because they're clearly still on there. When I click "get info" their is +/- GB660 in use and the files that pop-up don't even amount to more than +/- GB60..?

Any help would be greatly appreciated!

That's a strange one. On the installation screen that comes up is it possible you had accidentally selected to install on the G-Drive?

Check disk utility as well in case G-Drive has been unmounted. If it has maybe you can just mount it again.

 

[kevbradfield]

That's a strange one. On the installation screen that comes up is it possible you had accidentally selected to install on the G-Drive?

Check disk utility as well in case G-Drive has been unmounted. If it has maybe you can just mount it again.

I think that's exactly what I did (accidentally installed the update on the G-Drive). The issue is, I don't know how to uninstall it now? Basically I just want to revert my G-Drive back to what it was before the update but I don't know how.

Any suggestions/thoughts?

(Thanks for responding)

 

[ab225]

I'm unsure about this tbh. First things first, does the old drive appear in Disk Utility? I wonder if it's just been greyed out and unmounted. It's probably worth finishing an update of Big Sur on your normal system disk too in case that's a factor in not reading a new system partition. Worst case scenario you could just follow through on installing on G-Drive and delete the system files again after (as far as I know, a system install shouldn't delete your other files on the disk)

 

[kevbradfield]

Yes, the old drive does appear in Disk Utility, but when I double-click it just shows me a bunch of files that either have nothing in them or don't do anything when I double-click. I do think I need to finish the update, unfortunately the update is massive and right now I don't have enough space to install it because of my apps. The good news is, I managed to locate the files using search - there's just no way to access them directly in the G-Drive so I've back them up one by one (took hours😅) and now I can format the G-Drive if need be (I'd rather have the update to be honest but the files were more important which is why I posted).

Really appreciate you humoring me. I think this was just a rookie error of me interrupting the update and then panicking when I couldn't find what I was looking for.

Thanks again for your help!

 

[ab225]

Nice, good to hear you found a solution!