Joe T. Sylve, Ph.D.

Speculative telemetry is an APFS feature that tracks the lifecycle of speculatively downloaded files: content fetched to local storage before the user explicitly requests it, such as files prefetched by iCloud or the App Store.

Volume grafting is a mechanism introduced in macOS 13 that mounts a disk image’s APFS contents as a subdirectory of an existing volume.

In our posts on Keybags, Wrapped Keys, and Decryption, we covered the static encryption architecture of APFS: how keys are stored, unwrapped, and used to decrypt data.

In our post on Data Streams, we discussed how APFS implements file cloning through shared extents and reference counting.

APFS supports transparent file compression through the DECMPFS (Decompression File System) framework, shared with HFS+.

In our post on Inode and Directory Records, we noted that a single inode may be referenced by more than one directory record, as is the case with hard links.

APFS containers include an embedded EFI driver that allows UEFI firmware to boot from APFS partitions without requiring a built-in APFS driver.

SpiceCrypt 3.0.0 is out.

In our post on Containers, we introduced the Reaper as the subsystem responsible for garbage collection in APFS.

In our earlier post on Containers, we introduced the Space Manager as the subsystem responsible for tracking which blocks are in use across all storage tiers and for allocating and freeing blocks on behalf of volumes.