Last Year on My Mac: 1 iCloud Drive changes gear

Some of the biggest changes that Apple makes are those it doesn’t announce, or even mention in passing. For macOS, this year it was iCloud Drive. In release notes that happily tangled in the weeds of the Pets in the People album in Photos and AirTag sharing, the name iCloud Drive doesn’t appear once. Even in the full 14 page PDF account, its only mention is in the iCloud Passwords extension for Edge and Chrome.

For many iCloud Drive users, little seems to have changed either. If you had Optimise Mac Storage enabled, you can continue to evict files from local storage so they’re only held remotely, and if you had that setting turned off and hadn’t evicted any files, then what you see on your Mac continues to mirror that in iCloud. For a few, the change brought a major resync that could take many hours or days to complete, and if you’re one of those who played the system, had Optimise Mac Storage disabled but still evicted files, you could well have run into problems.

For all of us, though, the way that iCloud Drive works has changed. Optimise Mac Storage now switches it between two different operational modes: a replicated file provider syncing between local and remote copies of all files put in the cloud, and a nonreplicated file provider hosting and managing files that can be stored locally or whose data may only exist in the cloud.

From its inception in 2014 until the release of Sonoma this year, iCloud Drive had worked, as much as it ever did, using an elaborate and custom mechanism involving subsystems such as CloudDocs. At its best, it worked well, and even allowed you to evict files when Optimise Mac Storage was turned off, despite that not being part of the deal. Other cloud services such as Microsoft’s OneDrive and Dropbox had to do their own thing, as most of the mechanism for iCloud Drive was undocumented and private to Apple.

At a low level, iCloud Drive was only weakly integrated into APFS. For instance, its evicted files were represented locally as special hidden stub files that the Finder magically transformed into an illusion of what in reality only existed in the cloud. Of course, that wasn’t an option open to other cloud services, each of which was left to implement its own solution.

Apple introduced a new approach intended for all cloud storage services in 2021, developed by its Cloud File Providers team, and over those two years has matured that and added file system support for dataless files and directories, replacing the old stub files. It was in Sonoma that these were incorporated into a new version of iCloud Drive that arrived on our Macs when we upgraded them.

None of this guarantees that iCloud Drive won’t sulk when it should be syncing, and plenty have suffered traumatic conversions to this new FileProvider architecture. But experience so far is encouraging. Most importantly for us, it puts Apple’s service on a par with other cloud services. If they’re affected by problems in the FileProvider mechanism, then Apple has great incentive to fix them, as they’ll most probably also affect its own service. And what could have been considered unfair advantages of iCloud Drive are removed, integrating all cloud services with similar benefits in macOS.

In the longer term, it could open up some cloud services that haven’t yet been fully realised on Macs, such as backup to the cloud, a feature conspicuously absent from iCloud even though it was provided in Apple’s older services such as .Mac way back in July 2002. Now that Apple is selling iCloud storage as great as 12 TB, for those with suitably high bandwidth Internet connections this is already attractive, although at present it’s ironically only feasible using third-party software, not Time Machine.

So when you’re next looking through your Pets in the People album in Photos or sharing an AirTag, remember that it was in 2023 that Apple fixed iCloud Drive so that it just works much better than it used to.