![]() ![]() ![]() As that’s soldered onto the logic board, this requires replacement of the whole logic board. If your Mac’s internal SSD were to fail, as any external disk lacks the other two crucial containers, that Mac will no longer boot, and even if it did, cloning that external disk back to the internal SSD wouldn’t help you recover that Mac, as it would still be missing those other two containers.Ĭomplete failure of the internal SSD is fatal to an M1 Mac. When you clone an M1 internal disk to external storage, all that can be copied across is the normal boot container Apple_APFS. The normal boot container Apple_APFS isn’t quite the same as that on an Intel Mac either: one subtle but significant difference is that the Data volume isn’t named Macintosh HD – Data, as it is on Intel Macs, but simply Data. That Recovery volume is designated for recovery, but this container doesn’t have a separate booter volume. This includes a second part of iBoot and all that’s necessary for the M1’s full Recovery Mode. The Apple_APFS_Recovery container is dedicated to providing recoveryOS (or 1 True Recovery), which is stored on its Recovery volume. The xART volume provides trusted storage, while the Hardware volume contains hardware-related files such as logs and activation data. Here, the iSCPreboot volume is the designated booter, and the empty Recovery volume is for recovery. Like the two other containers, it can have designated ‘booter’ and ‘recovery’ volumes, indicated in the above diagram by an asterisk * next to the volume name. The first, Apple_APFS_ISC, is the iBoot System Container (iSC), and supports the iBoot firmware in the early boot process, as well as providing trusted storage for the Secure Enclave within the M1 SoC. The three containers on an M1 Mac’s internal storage have distinct functions. But that’s very different from the structure and contents of that M1 Mac’s internal storage. The same is true for an external bootable disk for an M1 Mac, which comes complete with its EFI partition and the single container with its boot Volume Group and a volume named Recovery too. Cloning that is an order of magnitude more complex, as snapshots can’t ordinarily be copied between volumes, and a Merkle tree of hashes has to be built to ‘seal’ it before it can be used. Applications are divided between both: bundled apps which come with macOS are on the System volume, but Safari and user apps are on the Data volume the file system uses special firmlinks to make those two directories appear one in the Finder.īig Sur changes that further: what’s mounted as the system is now actually a snapshot of a sealed volume known as the Sealed System Volume (SSV). ![]() Some system files, including data used by the macOS anti-malware utilities XProtect and MRT, are updated outside full macOS updates, so have to be stored on the Data volume, but appear as if they’re in the folder structure of the system. Although it’s more difficult to clone or copy this volume group, it’s by no means impossible. VM, containing virtual memory caches, which is upwards of 20 KB depending on use.Ĭatalina changed that by dividing the startup volume into two, a Volume Group consisting of a read-only System volume, and a writable Data volume, which is mounted in /System/Volumes and accessed via firmlinks from the System volume.Recovery, the Recovery Volume, of around 500 MB,.Preboot, a small volume of around 40-50 MB,.the startup volume, by default on the internal disk named Macintosh HD, which forms the root of the boot file system,.Within the latter are a minimum of four APFS volumes: Until Catalina, the structure of bootable System disks was relatively simple.Ī standard APFS boot disk in High Sierra and Mojave consists of an EFI partition and the main APFS container. I first drew attention to some of these issues four months ago, and more recently Mike Bombich of Carbon Copy Cloner has reiterated how the M1 changes ways to recover from disaster. This article looks at one change which is challenging and worrying many users: you can’t rely on cloning an M1 internal disk from a copy, as a method of recovering from disaster. M1 Macs bring a great deal more than better performance, and in some ways will modify old habits. ![]()
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