Mac users rejoice: You will finally be getting a modern file system to go with your class-leading hardware. Does it matter? Only if you care about your data. Here’s what you need to know.
This morning at WWDC, Apple announced that APFS will be the default file system in macOS High Sierra. That’s great news — and here’s why.
Last year Apple introduced their a new file system to developers, planning a 2017 release. The macOS’s UNIX core makes it easy to slide in new file systems, so APFS is easy to make the standard FS, as it is for iOS today.
APFS has some important capabilities, including
Those features get APFS up to feature parity with just about any modern file system, but there’s more. Here are the features that pro users will love:
SSD optimization: APFS offers a key new feature for SSDs: Write coalescing. Flash SSD writes are slow, so instead of many independent small writes, APFS will coalesce writes into a group and perform one big write for high performance.
No more repartitioning: APFS volumes can grow and shrink dynamically, up to the capacity limit of the underlying storage.
Cloning: Cloning creates a copy of a file (or directory) without taking up more drive capacity. As the clone is modified, only modified blocks are written to new locations. You can have multiple versions of a file with little overhead.
Snapshots: Common in enterprise storage systems, snapshots are read only instances of your file system. When blocks in the file system are modified, the old blocks are kept so the file system can be restored to an earlier point in time. Handy if malware pooches your Mac.
The once-over in the keynote didn’t cover some other issues that we might see, such as how APFS handles case-sensitivity. And, presumably, Time Machine and FileVault also now work with APFS.
Apple’s move to APFS is a decade overdue. I regularly see damaged files — I have over 20TB of storage capacity and store thousands of large files — that I believe are caused by HFS+ bugs.
So, I welcome APFS. However, a couple of cautions:
But, all in all, this is very good for Mac users and macOS. And long overdue.
Courteous comments welcome, of course.
