Understanding disk utility configuration and data persistence after a factory reset on Mac mini

Hi, I am having the worst experience trying to understand the set up within disk utility on my current Mac mini m2 (2023). Will someone please help me understand what I have going on in these two sections, and what is required to keep (during a wipe if not using reset feature). Please be as descriptive as possible I am really looking to learn and see what’s the issue currently with my configuration and persistence of data after a fresh whole system factory reset. I have seen a user profile ( @HWTECH ) on here that is very knowledgeable regarding Mac OS and I really would love to get a 1 on 1 help but I so appreciate anyone’s willingness to contribute. Thanks much

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Mac mini (M2, 2023)

Posted on May 2, 2025 03:45 PM

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D.I. Johnson

Level 7

30,971 points

Posted on May 2, 2025 05:11 PM

USArmyVeteran003 wrote:

How could the disk image parent offer the ejection option in the corner? If macOS base system is the recovery hidden OS why could it be ejected and how come there how come the container 5 has physical store name disk4s1 but device disk 5 then the base system under that is disk5s1 and the apple disk image media itself says device disk4 with child count 1. If you can compare what I show in the internal structure with the detailed questions above in relation to that section it would answer my questions. Please bear with me and apologies to the many photos I just really want to get to the bottom of this and learn it. Thank you

https://discussions.apple.com/content/attachment/fd54cb17-155e-416f-930b-a9ecbfd46a33

The disk image resides in ROM, I believe. The user is never expected to interact with it. It seems that Apple have finally done away with revealing it in Disk Utility in the latest macOS version.

As for the naming conventions, don't try to figure that out. It's all logically determined by the OS and relates somehow to the order that these devices become visible to the OS at startup.

I see nothing amiss in the screenshots that you've provided. As example, here is a partial from my own setup on a MacBook Air under Sequoia:

View in context

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21 replies

May 2, 2025 07:50 PM in response to USArmyVeteran003

USArmyVeteran003 wrote:

Okay thanks so how would you go about erasing your top level SSD? Would it be different due to the internal Mac OS base system not being revealed on your end? Or am I wrong about being able to completely wipe ssd and reboot in recovery to reinstall via internet recovery due to booting via Mac base os in internal after erasing SSD

Judging by the pics you've provided, the internal drive has already been wiped of user data.

Did you already use Erase All Content and Settings function? It appears so. That process will have wiped all of the user accounts and user info that were previously on the computer, leaving only the OS in its signed and sealed drive volume. It will have stepped you through the Setup Assistant the first time the Mac restarts after that.

If you feel compelled to actually manually erase everything from the internal drive - probably unnecessary - you must boot in recovery and use the Disk Utility app in the on the macOS Utilities screen to completely erase and reformat the internal drive. You'd have to select the internal device - APPLE SSD AP0256Z Media - and erase that.

Then you'd quit DU and launch the Reinstall macOS Sequoia app on the macOS Utilities screen. When prompted, you would select that Apple...Media device as the destination for the reinstall and follow the prompts to completion.

All that is unnecessary if you've used the Erase All Content and Settings function.

HWTech

Level 9

66,758 points

May 3, 2025 08:26 PM in response to D.I. Johnson

You provided great advice here. With Intel Macs I usually advise erasing the whole physical drive (except for Fusion Drives....then erase the hidden Fusion Drive item unless you want them to break a Fusion Drive & rebuilt it) because it also recreates the partition table and eliminates other problems users may encounter by improperly erasing the APFS volumes. When going a clean install route, may as well go just one step further. I wish Apple didn't make things so complicated & confusing.

I only added my second post in reply to the OP to provide a slightly different presentation as that can sometimes help and to clarify a few other items for the OP.

You did a great job here!

May 2, 2025 03:55 PM in response to USArmyVeteran003

May 2, 2025 03:56 PM in response to USArmyVeteran003

I have no vm either (reference to container disk 3 image not related to this picture)

May 2, 2025 05:56 PM in response to D.I. Johnson

I have already and this is the case before the installation. This is what led to the installation. Apple support has provided no guidance

May 3, 2025 08:35 PM in response to HWTech

HWTech wrote:

[...]

You did a great job here!

Thank you, my friend. 🙏🏽

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Understanding disk utility configuration and data persistence after a factory reset on Mac mini