silly question, how can macos with read-only system break ?

[antoine23]

Since Catalina the system is on a separate read-only volume. So, technically, it should not break, ever, right ?

Are there reports of system breaking (not booting or whatever) ?

And if it does, how ? I mean, how could it possible break software-wise ?

The only thing I could guess is a failed update, but other than that is there something else ?

 

[Nermal]

The most likely scenario is that something on the non-read-only part is conflicting with it. If a damaged or incompatible file is configured to load on boot then that could make the system unbootable.

 

[mfram]

People adding faulty or old third-party apps or drivers to their computers can cause a failure.

 

[antoine23]

People adding faulty or old third-party apps or drivers to their computers can cause a failure.

I thought kexts were removed and DriverKit and so on are user-mode only, isn't this the case ?

 

[antoine23]

The most likely scenario is that something on the non-read-only part is conflicting with it. If a damaged or incompatible file is configured to load on boot then that could make the system unbootable.

That seems a reasonable fault scenario, but it would boot then stop, which should allow the system to recover

Do you see any failure scenario where the system wouldn't boot ? like it used to happen with the question mark folder

I mean, could we reasonably say that the days of the question mark folder (and of using recovery) are over ? (for software only failures of course)

 

[galad]

Disks and SSDs are not perfect, things can randomly corrupts. However, it's a rare occurrence, it's been a long time since the last time I saw a boot disk corruption.

 

[antoine23]

Disks and SSDs are not perfect, things can randomly corrupts. However, it's a rare occurrence, it's been a long time since the last time I saw a boot disk corruption.

Thanks. Sure, that would count as hardware failure.
As a side note, that is hopefully rare enough considering the apple silicon macs do not boot at all (not even on USB nor recovery) if the drive fails