| I'm extremely confused by this: > With APFS, if you copy a file within the same file system (or possibly the same container; more on this later), no data is actually duplicated. [...] I haven’t see this offered in other file systems [...] To my knowledge, this is what cp --reflink does on GNU/Linux on a supporting filesystem, most notably btrfs, and has been doing by default in newer combinations of the kernel and GNU coreutils. This guy seems too well-informed and experienced in the domain to miss something so obvious, though. So what am I missing? Also interesting to me is the paragraph about prioritizing certain I/O requests to optimize interactive latency: On Linux this is done by the I/O scheduler, exchangable and agnostic to the filesystem. Perhaps greater insight into the filesystem could aid I/O scheduling (this has been the argument for moving RAID code into filesystems as well, though, which APFS opts against) -- hearing a well-informed opinion on this point would be interesting. Unless this post gets it wrong and I/O scheduling isn't technically implemented in APFS either. It seems like this perspective might be one written from within a Solaris/ZFS bubble and further hamstrung by macOS' closed-source development model. Which is interesting in light of the Giampaolo quote about intentionally not looking closely at the competition, either. |