Darth Vader
From the Dark Side
I had a problem today with cloning Big Sur - it wouldn't! This means that my usual way of making bootable clones now for macOS 11 onwards won't work thanks to Apple making such low-level access proprietary (by using a Sealed System Volume). Up to Crapolina I could make bootable clones so that I could run any suitable OS X or macOS via a USB HDD or SSD. For example a machine running Big Sur could be booted into El Capitan if needed. I can make an external bootable Big Sur but it won't be a clone and will need to use a Time Machine backup to restore users, apps and data.
This affects 3rd party cloners such as CCC and Super Duper.
A bit of research later and I discovered this bombshell "An Apple Silicon Mac won't boot if the internal storage has failed". So if the internal SSD gets corrupted it will brick the machine!
"What did come as a surprise, however, was a very subtle logistical change noted in a Product Security document published in February(link is external) regarding the new Apple Silicon Macs. A footnote at the very end of the document notes that, regardless of where the boot device is physically located, the boot process is always facilitated by a volume on the internal storage. The lightweight operating system on that volume ("iBoot") evaluates the integrity of the boot assets and authenticates the OS on that external device, then proceeds with the boot process from that external device. What does all of that mean? In theory it means that Apple Silicon Macs cannot boot at all if the internal storage fails. Lacking a Mac whose internal storage I was willing to damage to prove this, I contacted the authoritative experts within Apple in April and they unambiguously confirmed that that is the actual result – you can't boot an Apple Silicon Mac if the internal storage has died.
If you were making your backups bootable in case of hardware failure, then that's an extra logistical chore that you can now retire from your backup strategy."
Something to bear in mind if you are thinking of moving to an Apple Silicon Mac.
Cheers,
DV
This affects 3rd party cloners such as CCC and Super Duper.
A bit of research later and I discovered this bombshell "An Apple Silicon Mac won't boot if the internal storage has failed". So if the internal SSD gets corrupted it will brick the machine!
"What did come as a surprise, however, was a very subtle logistical change noted in a Product Security document published in February(link is external) regarding the new Apple Silicon Macs. A footnote at the very end of the document notes that, regardless of where the boot device is physically located, the boot process is always facilitated by a volume on the internal storage. The lightweight operating system on that volume ("iBoot") evaluates the integrity of the boot assets and authenticates the OS on that external device, then proceeds with the boot process from that external device. What does all of that mean? In theory it means that Apple Silicon Macs cannot boot at all if the internal storage fails. Lacking a Mac whose internal storage I was willing to damage to prove this, I contacted the authoritative experts within Apple in April and they unambiguously confirmed that that is the actual result – you can't boot an Apple Silicon Mac if the internal storage has died.
If you were making your backups bootable in case of hardware failure, then that's an extra logistical chore that you can now retire from your backup strategy."
Something to bear in mind if you are thinking of moving to an Apple Silicon Mac.
Cheers,
DV