Why does my late 2012 Mini refuse to boot from Ext HDD?

[BingClawsby]

Whenever upgrading the OS, people always talk about putting a test on an external. But I'll be damned if I can get the mini to boot from one. USB 3 hdd? it won't even show as a boot option. USB 2 will, but after a looooong booting process, at about 3/4 the way on the progress bar, it pops over to my Mac HDD to finish the job.

I use SuperDuper. Figuring maybe that was the problem, I tried a trial of CarbonCopy on a usb3 drive. IIRC, that actually managed to both show as a boot option and actually boot from it once, but then stopped doing both things altogether.

So today I'm wanting to go from High Sierra to Mojave, the end of the OS line for this machine. As an experiment, I created a partition on a firewire 400 drive and cloned my system onto that. I figured, Apple seems to hate USB since they didn't invent it afaik, and wants its users to suffer for it, but surely firewire will work cuz that's their baby!

And that's what I did.... and fark me if that doesn't flipping work either. Infuriating.

Going into startup prefs and choosing any of those externals as startup disk never helped either. I mean, is this all supposed to be some kind of a joke? My old '07 Macbook could boot from an external.

BTW, I choose the FW as startup, waited about 15 minutes for it to boot, gave up to come and write this, then checked on the machine..... still hasn't booted..... about a half hour so far. It as least jumped over to the main drive to finish the first time. Now just hanging forever. Grrrrrrr

So what I'll wind up doing is just install right onto my system and cross my fingers like I wound up doing with all the other OS upgrades I've done. Of course I keep 2 up to the last minute clone copies when i've done so. However I would love some kind of explanation for this seemingly sabotaging by Apple.

 

[joevt]

Why use SuperDuper or CarbonCopy; doesn't the Restore feature of DiskUtility work?

Use bless --info /Volumes/YourNewExternalOSVolumeName to see if it's blessed properly. If it isn't, then use the command:
bless --folder /Volumes/YourNewExternalOSVolumeName/System/Library/CoreServices --file /Volumes/YourNewExternalOSVolumeName/System/Library/CoreServices/boot.efi

Restart the computer into the Startup Manager (hold option key at boot until the icons appear). Do you see the new os's there?

 

[mdgm]

Did you update to the latest High Sierra 10.13.6 with all Security Updates installed?

The 2012 Mini can run Catalina. There are ways to run Big Sur on it though unsupported.

Another option is to boot off Thunderbolt.

 

[Boyd01]

Perhaps it has something to do with your disks? I used a 1tb Samsung T3 USB 3.0 SSD as the startup drive for my 2012 2.6ghz quad Mini for about 3 years. Never had a problem, didn't have to do anything beyond selecting it in the Startup Disk Prefs. Could also choose it by holding the option key at startup.

I had another 2012 base model 2.5 ghz Mini that used a 500gb Samsung T3 USB 3.0 SSD with no problems either. I use Carbon Copy to create bootable external disks.

 

[BingClawsby]

Why use SuperDuper or CarbonCopy; doesn't the Restore feature of DiskUtility work?

Use bless --info /Volumes/YourNewExternalOSVolumeName to see if it's blessed properly. If it isn't, then use the command:
bless --folder /Volumes/YourNewExternalOSVolumeName/System/Library/CoreServices --file /Volumes/YourNewExternalOSVolumeName/System/Library/CoreServices/boot.efi

Restart the computer into the Startup Manager (hold option key at boot until the icons appear). Do you see the new os's there?

Haven't heard about that 'blessed' thing since pre OSX days.
I'd need more info on what it's doing before I mess in terminal though. Don't know why that is still a 'thing' since the 'old' days, heh. Besides, the cloning software supposed to make the disk bootable. I would assume that 'blessed' thing is involved in that process.
Whether it still has anything to do with it, even having an ext OS volume appear when option booting, its confuses the machine for a long while, gives up, then jumps to the Mac HD (usually)

This last time I tried however it just hung. Gave it over an hour and a half.

Restore sounds like it'd wipe my machine clean to its brand new state and OS.

I use the machine for DAW recording (Logic) and have a ton of audio software, plugins with all associated authorizations. I don't even know what restore would do to all that mess, heh.

Did you update to the latest High Sierra 10.13.6 with all Security Updates installed?

The 2012 Mini can run Catalina. There are ways to run Big Sur on it though unsupported.

Another option is to boot off Thunderbolt.

Yep. Always keep things updated

Perhaps it has something to do with your disks? I used a 1tb Samsung T3 USB 3.0 SSD as the startup drive for my 2012 2.6ghz quad Mini for about 3 years. Never had a problem, didn't have to do anything beyond selecting it in the Startup Disk Prefs. Could also choose it by holding the option key at startup.

I had another 2012 base model 2.5 ghz Mini that used a 500gb Samsung T3 USB 3.0 SSD with no problems either. I use Carbon Copy to create bootable external disks.

Ugh... that's what kills me. Doesn't seem to be a problem for most. Drives me nuts

All my ports are used up...2 displays, usb audio interface and 2 sample drives , that FW drive I record to... usb hubs. Maybe something conflicts? I probably already thought of that and tried it with everything else unplugged though at some earlier time

 

[Boyd01]

I probably already thought of that and tried it with everything else unplugged though at some earlier time

I would unplug everything but the external disk and try again. But if you don't have an external SSD, I'd question whether it's worth the effort. I have tried booting from external hard drives before and it was really slow.

 

[Fishrrman]

What kind of external drive?
What make is the drive?
Is it 2.5" or 3.5"?
If 3.5" are you using the power supply?

What kind of enclosure?
Who made it?

Have you tried a DIFFERENT enclosure (if possible)?

I booted and ran my 2012 Mini from an external SSD in a USB3/SATA dock for 6 years (as my "main computer". Never a problem.
I can boot and run my 2018 Mini from any one of several external drives, both SSDs and HDDs.
Nearly all of the bootable drives are "CCC cloned drives"...

 

[BingClawsby]

You guys are not going to believe this and neither can I.

I had used an app called Boot Buddy to create a couple bootable installers for Mavericks and Sierra. I have those on one external that is partitioned for those and other OS clones. I was pretty sure those Boot Buddy's would work so I tried it. And yeah, the machine booted from them. Nothing major though as this just presents a GUI with choices for using Disk Utility, OS installer, Restore...

Ok, so the mini sees that external to boot from, at least, that utility. Although I knew it was useless, I then tried to boot from one of the OS clones on that drive. Mac booted but, as usual, was disappointed to see the Mac HD at the top of the HD list on the desktop.

Let me explain. I've owned 2 macs since OSX came out. A '07 macbook and this 2012 mini. I've had both mac hd's partitioned in 2..... one for upgrading the OS and an older OS so I could keep using some older software. On the mini, I keep a Mavericks partition so I can use my old photoshop CS5-6 and lightroom 5. Here's the rub..... I'm used to seeing whichever OS partition I boot from, that it's HD icon to go to the top of the list.

So, it just dawned on me, having just again tried to boot from a clone, to check and see whether or not I can eject any of the drives. Obviously, whichever drive is running the system, won't be allowed to eject.

And what the heck do you think I found, lol. My mac hd, sitting right on top, could be ejected. Whereas the clone I booted from, whose icon was showing some place else on my desktop, could not. Ipsofacto....the computer DID boot from the external drive!! I was always expecting that icon to jump to the top of the HD list to tell me that got booted!

What an idiot, lol. Doesn't explain why it couldn't boot from the FW drive clone I made yesterday though. Doesn't explain why I have a strong memory of some clones not appearing as choices option booting in the recent past. Unless I'm going nuts.

Longshot....but could having what startup drive I have chosen in prefs locked have anything to do with it? Because I did unlock it yesterday just out of curiosity if it might make a difference

 

[Boyd01]

It's very easy to determine what disk your Mac is using. Just go to System Preferences > Statup Disk and it will show there. As far as the lock... you need to unlock the preference to change disks, but aside from that it should have no effect.

 

[BingClawsby]

I would unplug everything but the external disk and try again. But if you don't have an external SSD, I'd question whether it's worth the effort. I have tried booting from external hard drives before and it was really slow.

Thanks for your help.

Actually boot up time with usb 3 not much different than that 5400rpm spinner they got in there, heh

What kind of external drive?
What make is the drive?
Is it 2.5" or 3.5"?
If 3.5" are you using the power supply?

What kind of enclosure?
Who made it?

Have you tried a DIFFERENT enclosure (if possible)?

I booted and ran my 2012 Mini from an external SSD in a USB3/SATA dock for 6 years (as my "main computer". Never a problem.
I can boot and run my 2018 Mini from any one of several external drives, both SSDs and HDDs.
Nearly all of the bootable drives are "CCC cloned drives"...

Thanks for your advice. See above. Most my externals are seagates in enclosures and one or two as bare drives which would go into an OWC 2 slot usb 3 dock they sell. I did try putting a boot on an Hitachi to see if it was a seagate issue at the time. Possibly I put and partition on a WD iBook hdd and tried that as well.

 

[BingClawsby]

It's very easy to determine what disk your Mac is using. Just go to System Preferences > Statup Disk and it will show there. As far as the lock... you need to unlock the preference to change disks, but aside from that it should have no effect.

Ah, of course. Get so overwhelmed with myriad of details, the obvious slips the mind. I actually looked a half hour ago in system profile to find that! Doh, lol

Gawd. This is almost on par with, "How come this damn toaster's not working??" "Well did you try plugging it in?"