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kevsdad

macrumors newbie
Original poster
Aug 17, 2024
2
2
On my M1 Mac Mini I moved the operating system from its' 256 GB home drive to a larger capacity (4 TB) external SSD drive about a year ago and it works fine with no issues at all. Is it safe to delete the operating system on the original internal drive?

TIA.

Scott
 

jdb8167

macrumors 601
Nov 17, 2008
4,859
4,599
On my M1 Mac Mini I moved the operating system from its' 256 GB home drive to a larger capacity (4 TB) external SSD drive about a year ago and it works fine with no issues at all. Is it safe to delete the operating system on the original internal drive?

TIA.

Scott
Probably not depending on what you mean. You can’t delete the system software as far as I know because of the locked volume. If you format the disk and manage to remove the boot volumes then your external won’t boot since it needs the boot volumes on the internal. I would think the safest choice is just leave everything alone. But if you want to experiment and have another Mac then the worst that happens is that you have to do DFU repair.
 

Mike Boreham

macrumors 68040
Aug 10, 2006
3,913
1,896
UK
Probably not depending on what you mean. You can’t delete the system software as far as I know because of the locked volume. If you format the disk and manage to remove the boot volumes then your external won’t boot since it needs the boot volumes on the internal. I would think the safest choice is just leave everything alone. But if you want to experiment and have another Mac then the worst that happens is that you have to do DFU repair.
I agree erasing the whole boot drive would stop the external booting because it would destroy the all important Preboot volume on the internal. But I would think (not 100% sure) the OP would be safe to delete the internal volume pair (System and -Data volume), which Disk Utility can do if you are booted from another drive or Recovery. The Preboot volume is outside these two.

@kevsdad However 256GB is neither here nor there if you are booting from a 4TB external so my inclination would be to keep it and ignore it. It might be useful for troubleshooting sometimes.

Is your 4TB boot drive Thunderbolt or USB? macOS sees external Thunderbolt drives as equivalent to internal drives, fully supporting SMART and TRIM, as well as being faster. None of these is essential and external booting USB works fine.
 
Last edited:

kevsdad

macrumors newbie
Original poster
Aug 17, 2024
2
2
I have no problem leaving it there as I have no need for the extra 256 GB. Thank you for the advice, particularly concerning the Preboot volume. The external is Thunderbolt, but even so, I think I'll just leave it and ignore it as I have been.

Thanks again!
 

fibercut

Suspended
Aug 1, 2024
29
9
I have no problem leaving it there as I have no need for the extra 256 GB. Thank you for the advice, particularly concerning the Preboot volume. The external is Thunderbolt, but even so, I think I'll just leave it and ignore it as I have been.

Thanks again!

Learn about using the older alias and linked shortcuts on Applications, Music and email boxes folders to the external could save huge SSD files! you can out one of those shortcut for huge library folders by living an alias of the whole order even!
 
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