Formatting error

[Macintosh1984]

Hi!

I prepared a pendrive with macOS Sequoia 15.1 to format my iMac M3.

From Disk Utility if I select APPLE SSD AP1024Z and then click Erase, I get the error couldn’t open device: (-69877).

How to fix?

 

[Nermal]

There is usually no need to format and reinstall the OS on a modern Mac. Use Erase Assistant instead.

If your goal is a clean installation of 15.1 then do an in-place upgrade first, then use Erase Assistant.

 

[Macintosh1984]

In the meantime I also deleted the small Macintosh HD and Macintosh HD - Data volumes, so I find myself without an operating system.

How do I overcome this situation? Is it enough to recreate the Macintosh HD volume without worrying about giving the formatting command on APPLE SSD AP1024Z and therefore this error does not matter?

I specify that I find myself in this situation, but I had already updated the iMac M3 to Sequoia 5.1, now I just wanted to do a clean install. Another thing, despite having used Sequoia for months, if I also access the Recovery partition, it tells me to reinstall Sonoma, because the recovery partition was not updated to Sequoia when I switched from Sonoma to Sequoia a few months ago?

Help me solve it from Disk Utility with boot from pendrive.

 

[Wolf1701]

In the meantime I also deleted the small Macintosh HD and Macintosh HD - Data volumes, so I find myself without an operating system.

How do I overcome this situation? Is it enough to recreate the Macintosh HD volume without worrying about giving the formatting command on APPLE SSD AP1024Z and therefore this error does not matter?

I specify that I find myself in this situation, but I had already updated the iMac M3 to Sequoia 5.1, now I just wanted to do a clean install. Another thing, despite having used Sequoia for months, if I also access the Recovery partition, it tells me to reinstall Sonoma, because the recovery partition was not updated to Sequoia when I switched from Sonoma to Sequoia a few months ago?

Help me solve it from Disk Utility with boot from pendrive.

A few days ago I created a USB stick with sequoia and formatted macintosh hd. No problems except that then sequoia did not want to install itself in macintosh hd (if selected it would return to the main menu). Putting it in DFU didn't work either.

So I created a usb stick with sonoma, installed (no problems) and then upgraded to sequoia.

As I wasn't happy with this solution I then put it in DFU (at this point it was working) and put sequoia clean and tidy.

 

[Fishrrman]

OP:

What happens if you try the following?

a. set aside the USB flash drive for now. Don't use it.

b. If the iMac is not shut down, press AND HOLD the power on button until the screen goes dark, then...

c. Press AND HOLD the power on button. Don't let go until you see "LOADING startup options".

d. I believe you will then see a screen with an icon "options". Click that to select it, and then click "continue". This should take you to the "recovery" area.

NOTE: If you're connected via wifi (instead of ethernet), you may be asked to enter your wifi password at some point, not sure. Ethernet is better for a job like this.

e. Among the options you should see one that reads, "Reinstall xxx" (with xxx being a version of the OS). My advice is to ACCEPT WHATEVER VERSION OF THE OS RECOVERY OFFERS TO YOU. It's called "any port in a storm".

f. See if the install will go through this way.

The goal:
To get the Mac bootable again, regardless of the OS.

Fishrrman's "Mac Rule Number 1":
A Mac that boots (to any version of the OS) is preferable to one that won't boot at all.

Good luck.

 

[Macintosh1984]

I'll update you:

My iMac M3 ordered as soon as it came out, had macOS Ventura, immediately updated to Sonoma and when Sequoia came out, I updated again. Always updated, never formatted. Yesterday I decided to format, creating a USB stick with macOS Sequoia 15.1.

1) Starting the Mac from a USB stick, from "Disk Utility" I clicked on "Show all devices", selected "APPLE SSD AP1024Z Media", "Initialize", getting the error "couldn’t open device: (-69877)"

At this point I clicked on "Show volumes only" and I managed to format "Macintosh HD".

Then I moved on to the macOS Sequoia installation option, always from the USB stick, the installation did not proceed with the error "failed to check if a disk is fde".

2) At this point I started the Mac in "Recovery", also in this case in "Disk Utility" I got the error "-69877" trying to initialize "APPLE SSD AP1024Z Media" and to my great surprise instead of finding the option "Reinstall macOS Sequoia", I had "Reinstall macOS Sonoma". I decided to reinstall "macOS Sonoma" from "Recovery" and then update to "Sequoia" via "System Settings".

Obviously I'm not happy with what I did because although the installation of "Sonoma" was clean, the one to "Sequoia" was an update.

Can you explain to me why I encountered problem 1) and why the "Recovery" partition was "macOS Sonoma" even though I was already coming from "macOS Sequoia"?

In your opinion, if I access "Recovery", now I see "Reinstall macOS Sequoia", if I initialize "Macintosh HD" a restart occurs, is it possible that then by turning back on in "Recovery" I will find "Reinstall macOS Sonoma" again? Or can I be sure that the "Recovery" partition remains "macOS Sequoia"? Because I could decide to reformat again and reinstall "macOS Sequoia" from "Revovery", to have the cleanest installation possible, to overcome the problems of point 1).

Can you confirm that for a DFU installation you need another Mac connected via USB-C?

 

[Nermal]

Because I could decide to reformat again and reinstall "macOS Sequoia" from "Revovery"

As the risk of repeating myself, don't do that. Use Erase Assistant. You should only be reinstalling from Recovery if the system doesn't boot.

Obviously I'm not happy with what I did because although the installation of "Sonoma" was clean, the one to "Sequoia" was an update.

Whether you install 14 and update to 15, or do a "fresh" install of 15, the system volume will be identical.

 

[Fishrrman]

Question for Nermal (which should provide info for the OP as well):

When doing a "full system update" (from one version of the OS to another, such as 14 to 15), does the (hidden) Secure System Volume get completely replaced/re-written (to become the "new OS")?

I believe this is what the OP is concerned about.

I'm going to GUESS that it DOES, and that this occurs even with ".x" updates (such as 15.0 to 15.1)...
I could be wrong.

 

[Nermal]

I'm about 98% sure that it does. Given that the system checks the volume hash on boot, I can't imagine that Apple would have different "versions" of 15.1 with different hashes that depend on how you got there.

 

[Ben J.]

I'm about 98% sure that it does. Given that the system checks the volume hash on boot, I can't imagine that Apple would have different "versions" of 15.1 with different hashes that depend on how you got there.

Yes. The Signed System Volume is 'untouchable', therefore there is no need to reinstall it. If it works and starts up, there is absolutely no reason to do a clean install to fix problems. The 'erase this mac and settings' is what you want to focus on. It erases the 'Data' volume that contains everything else but the system and the mac will boot to the "Hello" screen like it was new, and let you create a new user account or import one from a disk or backup. Even the Recovery partition, doesn't matter if it's not the same version as the main system, it'll work.

Any corruption of the SSV (if you can find a way to do it) will render it unbootable and useless. That's when you need to do a macOS internet install. It will always install the latest version compatible with the mac model.

The only situations (that I know of) you'd need to create a 'bootable usb installer' is when you want to install, downgrade to, an earlier version than the latest.

 

[Macintosh1984]

Thank you all, but you have not answered why when I initialize APPLE SSD AP1024Z Media I get couldn’t open device: (-69877) and why from USB Stick I get failed to check if a disk is fde.

 

[Macintosh1984]

In addition to what was left pending with my previous post, I wanted to understand if it is right to try to format by clicking on APPLE SSD AP1024Z Media or as per this document https://support.apple.com/102506/ at point 6-7-8-9), you have to click on the Macintosh HD volume?

At point 15) it then says "If you previously installed a macOS upgrade, you might be offered the macOS that you were using before you upgraded", so the doubt remains that Sonoma will be proposed to me, even if my computer was born with Ventura!

Then reading https://support.apple.com/guide/mac-help/mchl768f7291/, that I have to set Reduced Security to format APPLE SSD AP1024Z Media and reinstall macOS Sequoia from USB without having therefore couldn’t open device: (-69877) and failed to check if a disk is fde?

 

[Macintosh1984]

I conclude my story.

- Sequoia already installed
- From Sequoia USB stick, the initialization of APPLE SSD AP1024Z Media worked, but there is one thing I noticed, after the reboot, the Macintosh HD volume does not have any OS installed, it is not possible to initialize APPLE SSD AP1024Z Media again, that's where it appears couldn't open device: (-69877)!
- There was no way to install Sequoia from USB stick (failed to check if a disk is FDE)!
- Forced in Recovery to reinstall Sonoma and then update to Sequoia

Not satisfied, with the system updated to Sequoia, I also used the "Erase contents and settings..." function, because in this way I know for sure that a reset was done under Sequoia directly.

I remain incredulous as to why from a USB stick with Sequoia, I received the error failed to check if a disk is FDE and for the first time in decades, I was not able to do a simple formatting and "direct" installation of the latest system in my USB stick.

 

[Fishrrman]

"the Macintosh HD volume does not have any OS installed"

I don't believe the "Macintosh HD" is supposed to have "an OS installed".

Rather, the OS is "installed" onto the Secured System Volume, which is both invisible and inaccessible to the user.

The "Macintosh HD" that you (as the user) see on the desktop is a fictional "concoction", a "blending together" of the Sealed System Volume AND the "Macintosh HD Data" volume (the latter is where all user applications, data and settings are stored). It is, essentially, an "illusion".

When you use "erase all content and settings", you are "erasing" the Macintosh HD Data volume (all the "stuff" that YOU have installed), but the SSV is either "left alone, intact" OR it gets restored to "like new".

"I remain incredulous as to why from a USB stick with Sequoia, I received the error failed to check if a disk is FDE and for the first time in decades, I was not able to do a simple formatting and "direct" installation of the latest system in my USB stick."

Things have changed.
Apple has "changed" them.
It is... what it is.
Their "new way"...

(if I haven't described things correctly above, I welcome correction from others who know...)

 

[Macintosh1984]

I still don't understand on a technical level how it works "now" with volume management, hidden partitions, etc.

I know for sure that it is possible to format APPLE SSD AP1024Z Media only once if there is an operating system installed on the Mac. After rebooting, if you try again you get "couldn't open device: (-69877)".

I know for sure that I could not install from USB stick Sequoia (failed to check if a disk is FDE).

In the end I adapted to the procedure that Apple wants now!