Στον απόηχο του χθεσινού keynote, όπου παρουσιάστηκαν τα macOS Sierra, iOS 10, watchOS 3 κ.α. έχουμε μία σημαντική είδηση η οποία δεν έτυχε αναφοράς από την Apple. Το νέο APFS File System που σχεδίασε η Apple με σκοπό να αντικαταστήσει τα υπάρχοντα HFS και HFS+.
Το νέο File System είναι scalable, υποστηρίζει όλα τα λειτουργικά της εταιρείας (iOS, macOS, tvOS και watchOS) μπορεί να χρησιμοποιηθεί από το Apple Watch έως το Mac Pro.
Είναι βελτιστοποιημένο για χρήση σε Flash/SSD και στα δυνατά του σημεία συγκαταλέγονται οι εκτεταμένες δυνατότητες κρυπτογράφησης αλλά και πλήθος σύγχρονων τεχνολογιών που περιγράφονται παρακάτω:
APFS File System Features
Flash / SSD Optimization
APFS is optimized for Flash/SSD storage and can be used with traditional hard disk drives (HDD). A unique copy-on-write design uses I/O coalescing to maximize performance while ensuring data reliability.Space Sharing
Space Sharing allows multiple file systems to share the same underlying free space on a physical volume. Unlike rigid partitioning schemes, which pre-allocate a fixed amount of space for each file system, APFS volumes can grow and shrink without volume repartitioning.Each volume in an APFS container reports the same available disk space, which is equal to the total available disk space of the container. For example, for an APFS container with a capacity of 100GB that contains volume A, which uses 10GB, and volume B, which uses 20GB, the free space reported for both volumes A and B is 70GB (100GB – 10GB – 20GB).
Cloning of Files and Directories
A clone is a nearly instantaneous copy of a file or directory that occupies no additional space for file data. When a cloned file is modified, only the modified blocks are written to new locations on storage. In this way, the file system can store multiple revisions of the same document with less storage space.Snapshots
A snapshot is a read-only instance of a file system on a volume. The operating system can use snapshots to make backups work more efficiently, and offer a way to revert changes to a given point in time.Fast Directory Sizing
Fast Directory Sizing allows APFS to quickly compute the total space used by a directory hierarchy, and update it as the hierarchy evolves.Atomic Safe-Save
Apple File System introduces a new Atomic Safe-Save primitive for bundles and directories. Atomic Safe-Save performs renames in a single transaction such that, from the user’s perspective, the operation either all happens or does not happen at all.
Προς το παρόν και μέχρι να ολοκληρωθεί η ανάπτυξη του APFS File System το οποίο διατίθεται ως Developer Preview στο macOS Sierra, υπάρχουν μερικές αδυναμίες οι οποίες ωστόσο αναμένεται να διορθωθούν κατά το λανσάρισμα του (2017):
- Startup Disk: APFS volumes cannot currently be used as a startup disk.
- Case Sensitivity: Filenames are currently case-sensitive only.
- Time Machine: Time Machine backups are not currently supported.
- FileVault: APFS volumes cannot currently be encrypted using FileVault.
- Fusion Drive: Fusion Drives cannot currently use APFS.
