The first reference to macOS 10.13 appears, to be presented at WWDC17

Inside APFS, Apple's new file system

A few weeks ago, in a seemingly harmless session at WWDC 2016, a highly anticipated novelty surfaced for advanced users, professionals in the area and enthusiasts in general: Apple File System, better known as APFS.

The new file system developed by Ma brings a series of news related to resources, speed and security. Here's what Apple said about him at his WWDC session:

Apple File System (APFS) is a new generation of file system designed to adapt from Apple Watch to Mac Pro. APFS is optimized for flash / SSD storage, and is designed with encryption as a primary feature.

Everything is very beautiful, but not very detailed, do you agree? For now the time has come to take a deeper look at everything again that APFS will bring and what this change means, in practice, for all users even those who have no idea what a file system means.

iCloud Drive from macOS Sierra on a MacBook next to the app running on iPad and iPhone

Let us start, as usual, with a brief history to put ourselves in context: for the past 18 years, the file system used by Apple is HFS + in turn, a kind of “new version” of HFS, a system created more 30 years. This means, of course, that HFS + has a number of shortcomings when it comes to functionality: it was designed for volumes with capacities hundreds of times smaller, on hard disks that reached ridiculously lower speeds compared to today. It does not have a lot of modern resources and is used by professionals in the field, not even sensitive to capitalization of letters. He, in a word, outdated although he still serves his purpose well.

The reason behind Apple cleaning HFS + completely and building a new system basically from scratch is most likely to do with the fact that it would be much more expensive in terms of both money and energy to spend the rest of the time working on minor improvements to the (now) dying system. We then arrive at APFS.

The Apple File System is already available, as a preview, on macOS Sierra beta. This initial version, however, still does not offer many functions: it is possible to create a volume in the new format, but it cannot be used as a boot disk, nor does it support Fusion Drives (which equip iMacs and Macs mini) or Time Machine ie , basically something for very basic tests. This, however, already reveals a number of interesting things.

The first major "face" of APFS, as widely advertised by Apple, is security. The great thing here that the system adopts the encryption as part of your own core, that is, already as the system standard. By way of comparison, HFS + required a solution "over the top" of the system to encrypt files in the case of OS X, the old FileVault, which is obviously less reliable. In APFS, there are three main protection options offered: 1. non-encrypted; 2. with a unique key for metadata and user data, or; 3. with multiple keys and individual options for metadata, files or even sections of a very useful file, for example, for mobile devices where all data is encrypted.

Apple File System

The other great novelty of the new system is related, of course, to velocity: APFS was designed especially for the dizzying transfer rates of drives flash drives and SSDs that are beginning to become standards in the computing world.

Some of the features related to operating speed include the Fast Directory Sizing, which makes it possible for the system to calculate the space used by a folder and all its contents in a single time and just update this information as things enter and exit like this, it is always possible to check the size of a folder instantly; The Instant Cloning ZFS brings the ability to instantly clone any file or folder without the copy occupying the same space as the original, only changes made to the duplicate take up space, with the core of the file maintained only in the first.

Instant Cloning is only possible thanks to support in APFS for Sparse Files (Sparse files), which are a type of digital file that uses available space more efficiently by writing its most basic information in metadata instead of occupying entire blocks of the volume with its complete data. When reading this type of file, the system simply completes this metadata with “common” data, without causing any loss of performance. The space is used in a much more intelligent way.

Use of space, also, the main technique of another very interesting resource: the Space sharing allows two APFS volumes (for example, that of the main system and that of a virtual machine) to collaborate with each other's space in other words, a space-hungry volume can borrow from the other for a critical task, for example . As a result, the immobile and impassable character of HFS + and other current file systems will be left behind.

Another of the features most requested by developers in the new Apple file system is that of Snapshots. a snapshot , roughly speaking, the state of a system at a specific point in time, available for read-only; with them, it is possible to perform backups and restores much faster, since only the changes registered between the last and the next snapshot need to be saved and applied to the entire volume. Shared systems, as in companies and educational institutions, will also benefit from the novelty.

Time Machine running on a MacBook Air

Speaking of restorations, the next point on our list of news is support for Timestamps per nanosecond. For that, let's go back to HFS +: it is able to set the date and time of a given file with a second. With the new APFS feature, this marking takes place with the precision of a nanosecond; in other words, combining this with instant cloning capabilities, we will have access to much more sophisticated backups, with almost infinite options. Time Machine will benefit, and how, from this novelty.

Speaking of file date and time, moreover, another huge benefit of APFS if you intend to use your same Mac for the next 25 years: for a number of technical specifics, HFS + s supports file classification until February 6, 2040, while the Apple File System does not have a terminal date. Ah, also good to note that APFS supports 64-bit file naming (versus 32-bit HFS +) and sensitive capitalization of letters, bringing it to more than five quintiles the maximum number of files on the same volume.

Volume, system and file integrity is also a major focus of APFS. An example of this is the introduction of a resource that has long been requested by experts of the area: the Checksums (Checksums). They are used to count the number of bits at the beginning and end of the specific data transmission, and to compare these numbers to verify that the transfer has been completed correctly. In this way, the system is much more immune to corruption and failures in general.

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Having finished the list of news, at least the ones we already know, it is good to remember, the question remains: how to migrate from a file system to a completely different one? Fortunately, Apple has thought about it all and us users, we won't have to move a straw. More or less like what happened in the Windows world with the transition from FAT to NTFS, which this exchange will simply create new metadata within the free space of the HFS + volume and, from there, convert everything to APFS. Everything is exactly where it is, and the system at least in theory is totally fail-safe.

Ma's plan that, in 18 months, the Apple File System is already standard on all your devices as she says, from Apple Watch to Mac Pro.

Of course, like every introduction to a new file system, compatibility issues may come along the way as they do, for example, when we want to use an external HDD on Windows and Mac. Apple will also have to create a specific APFS driver for Windows, so that Boot Camp continues to work. There are, however, lesser things in view of the undeniable benefits that the introduction of the new system (related to speed, security, integrity and everything else) will bring to the millions of users of Macs and iGadgets around the world.

Let him in the afternoon to consolidate!