I'm trying to erase and then install a new macOS version onto the internal ssd drive on my MacBook. But when booting it up in internet recovery mode it says the disk is both external and read only. How can I make it writable?
MacBook Pro 15″, macOS 11.4
UPDATE:
I solved it.
I had previously used FileVault on the disk and that's why it couldn't be edited or be found at times.
I tried to use the disk utility to erase the disk. But that doesn't completely erase it. What I did to solve it was boot up Ubuntu on the MacBook and from there erase the disk completely, which should take longer then the erase does in disk utility. Then the disk problem stopped.
Only thing I can think of trying is...
Have you done a PRAM reset, CMD+Option+p+r...
Reset NVRAM on your Mac - Apple Support
In fact, do 3 in a row, takes a bit of time.
I've looked a bit more into it. I think it can have to do something with that I hade a partition of 125 gb on it before with Apples FileVault encryption and then I expanded the partition into a large portion of 500 gb and after reboot this happened.
I have tried repairing the disk by running the following command in the internet recovery terminal:
diskutil repairDisk /dev/disk0
But all I got was an error.
After 1 minute or so the internet recovery also kinda forget the disk0. It just disappears from nowhere. After that happens, which usually does after one minute after entering recovery I get that the disk0 cannot be found when typing:
diskutil info /dev/disk0
Very odd. I would be a bit concerned that the SSD may be failing since its SMART Status was not supported which is unusual for an Apple OEM SSD. Plus the weirdness of the volume appearing as orange indicating an external volume.
Is that SSD the one which shipped with that laptop from the factory?
FYI, your picture of Disk Utility shows an older version (macOS 10.12 or earlier). Maybe if you were using macOS 10.13+ and APFS file system, then it may be due to the older OS not being able to properly interpret the new drive layout although I would expect it to be able to determine the SMART Status. To attempt to properly recreate the partition table & file system, you need to use the "Partition" option where you create a single GUID partition and the MacOS Extended (Journaled) file system since the "Erase" feature in the older OS only works on the existing volume unlike later versions of macOS 10.13+. Here is an article which explains that process which applies to macOS 10.6 - 10.12.
https://eshop.macsales.com/tech_center/formatting/Mac_Formatting_6-10_R3.pdf
However, macOS & Disk Utility sometimes have difficulties erasing the physical drive when something goes wrong or there is an unexpected value somewhere. If you are familiar with the command line, then you can just write zeroes to the beginning of the drive to destroy the partition table using "dd" (most times that will work, but once in a while another OS may be required to destroy the existing partition table as you discovered).
I'd like to know this answer, too!
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Disk Utility reset MacBooks internal ssd drive not writable
