APFS (like many modern file systems but unlike its predecessor HFS+) supports copy-on-write. This means you can logically copy a file – it looks and behaves like a distinct file – but it doesn’t immediately copy the file’s contents on disk – it merely shares them with the original. Only if and as you modify… Read more
Note: this guide was written circa macOS 10.13 High Sierra, in 2018. Its accuracy has not been verified for newer macOS releases. Curiously there’s very little information out on the web (at time of writing) on how to create (or expand) a Fusion Drive without erasing its contents first. It’s entirely possible to do so… Read more
Alternate title: Apple’s file system engineers are sadly naive. I was quite disappointed to see that APFS isn’t even trying to provide data integrity. Data integrity is kind of step 0 of any file system, and checksums or use of ECC is pretty much standard in modern & leading-edge file systems. APFS doesn’t want to… Read more