Testing out snapshots in Apple’s next-generation APFS file system
arstechnica.com
arstechnica.com
It's also currently very beta. The management tools are currently CLI-only; it can't be used on a boot volume; it's case-sensitive (not case-preserving, but actual-for-real case-sensitive); it checksums metadata but not all file data.
Apple intends for it to be their whole-ecosystem file system (and it's already showing up in iOS - https://arstechnica.com/apple/2017/01/ios-10-3-will-be-apple...), and the rollout will be fun to keep an eye on.
Today, APFS is an interesting beta project and if you're an apple developer—especially one whose apps do more than casual manipulation of the file system—you should start getting your hands dirty with it. From an end-user perspective, getting proper support of snaps and clones will be a welcome relief, especially since it seems blindingly obvious that APFS snaps will replace Time Machine's current mess of links.
But yeah, it's beta. You can't use it in production yet (can't even boot off of it). Will need to wait until later this year to get a more mature version of it before it can be adequately benchmarked and evaluated in prod.
The fact that it's booting right now on iOS devices with 10.3 Beta with zero issues should tell us that the current APFS build at Apple is already way ahead of what we know about it and Apple did announce that all platforms will be using APFS this year.
So I'm wondering if they're going to release the final preview in 10.12.x at all or it'll be in 10.13 and auto-converted like iOS 10.3.
Notably, APFS checksums its own metadata but not user data. Which is a little odd for a new filesystem in 2016, but there you have it.
Not clear at this stage if it will make it to production release, but starting on iOS devices makes a lot of sense given it's likely subjected to a smaller subset of crazyness compared to Macs.
More than "supposedly", I'd say—if you're using the iOS 10.3 beta now, your phone's filesystem has already been updated to APFS. :)