The Apple File System (short APFS) is the successing file system of the HFS+ file system published in 1998. Apple announced it in summer 2016 for the first time. In the beginning the file system was only used for mobile iOS devices (version 10.3) and later on for macOS High Sierra for MacBook, Mac Pro and iMac. The benefits advertised are aimed at the operation with SSD flash media and promise an enhanced peformance, storage optimization and additional security thanks to native encryption and snapshots.
Special APFS Apple File System Features
- Dynamic capacity enlargement/changes from APFS drives without repartitioning.
- Space Sharing: Several logical drives share the same physical storage space.
- Snapshots: Efficient data backups with read-only snapshots and reset points.
- Encryption of complete volumes, individual files and meta data (single and multi key).
- APFS uses AES-XTS/AES-CBC encryption according to the hardware used.
- Thanks to fast directory sizing the file system is able to calculate the capacities needed fast
- and keep them up-to-date.
- COW clones: Clones (copy-on-write) are immediately available files which don't have additional memory requirements. The diretory entry is duplicated and only the modifications of the file are documents, saved and rewritten without copying the complete file. This enables lots of variations of a single file in different versions without taking up lots of disk space. This also apllies to ZFS and BTRFS.
- With Atomic Safe-Save name changes can be processed in one single operation.
- Optimization for flash media and SSDs. The application on regular hard drives is not excluded. Apple Fusion Drive (the proprietary combination of HDD and SDD) is not supported by APFS.