Apple's new file system "APFS" adopted by macOS


It started from the early June 14, 2016WWDC 2016And the latest OS "mac OS" for Mac was announced. thisMacOS has various new functionsHowever, it became clear that the file system is also new.

Apple File System Guide - Introduction

Digging into the dev documentation for APFS, Apple's new file system | Ars Technica

In the keynote lecture, MacOS story focused on topics about new functions, and file system was not mentioned, but after the lecture, materials for developers were released. A new file system is "Apple File System (APFS)It is calledInodeBase ones.

◆ Snapshot & Clone
Ars Technica at the IT news site cited "snapshots" and "clones" as interesting elements.

"Snapshots" are read-only at any point in the systemInstance(Backup), and in Windows it says "Shadow copyIt corresponds to. When changes are made to the file system from the state of the snapshot, changes are saved as deltas. Create a backup of Mac that was in OS X, restore from that backup "Time Machine"It is said that it exists to renew and replace the function.

"Clone" is a writable one, as opposed to the snapshot being read-only, cloning files and folders. At this time, the clone is created immediately without waiting for the copy of the data. As changes are added to the original file, changes are recorded, making document revision and tracking of versioning easier.

◆ Timestamp
Timestamp processing will be in units of seconds to nanoseconds, allowing you to track the order of operations more finely.

◆ Crash Protection
"Crash protection" is added to guarantee that the file will not be damaged even if the power supply is lost while writing the file.

◆ Encryption
As an encryption function, "FileVaultThere were three, but strengthening this, you can choose three options - "no encryption" "single key encryption" "multi key encryption". This means that various demands are covered from people who do not care about encryption etc. to people who do not want anyone to know any secret.

◆ Folder size
Speeding up the folder size calculation called "Fast directory sizing" is done.

◆ Space sharing
When creating multiple volumes, the same in storagechunkCan be used. Ars Technica expresses this as the concept of space sharing. For example, even if the disk capacity is 1 TB, by sharing the chunk, it is possible to place four 1 TB volumes, which makes it possible to add physical storage without changing the volume size It is possible to do.

APFS is a developer preview version from OS X 10.12 (macOS Sierra 10.12) and will be released in 2017.

in Software, Posted by logc_nt