One of the new features of macOS Sierra is that it can automatically ‘manage storage’ on your Mac. What this means is, if you’re getting low on SSD space, macOS can automatically upload older and larger files to iCloud and then delete them from your Mac. When macOS deletes a file, it leaves an alias that will download the file from iCloud as required.

Effectively, you don’t have to worry about how much physical storage your Mac has – you can just treat it as an infinitely large drive and macOS takes care of shifting things back and forth from the cloud as required.

That’s great in theory, but there seem to be a few flaws in practice …

First, macOS for some reason puts different elements of the feature in two different places on your Mac. One aspect of it is where you’d expect it: System Preferences > iCloud. Here you can switch the feature on or off for files stored on your iCloud Drive. Click the Options button next to iCloud Drive.

The other element isn’t in System Preferences at all: you instead have to go to the Apple menu > About this Mac > Storage > Manage. At that point, you can choose to store all your files on iCloud when necessary, retaining only recently-opened ones on your Mac. That’s a pretty well-hidden feature!

You could argue that’s such a dangerous feature that it should be well-hidden. Effectively you are switching from a belt-and-braces system, where you have three copies – one local, a second in your local Time Machine backup, a third on iCloud – to just a single copy. That’s way too risky for my tastes, especially given the somewhat flakey reliability record of Apple’s cloud services.

But Mac users may also be running that same risk without even realizing it. Because that first option – to ‘Optimize Mac Storage’ for files stored on iCloud – is on by default in my experience. This means that, for any file on iCloud, your Mac could be deleting files from your Mac without your knowledge or permission. That should never be the case.


It should never be the case for safety reasons, but also for reasons of practicality. We don’t all live in an always-connected high-speed Internet world, where we can access any cloud file simply by waiting a few seconds. Many of us frequently work on the move, on trains, planes and metro systems where Wi-Fi is either unavailable or exceedingly slow and unreliable. This is not the time when you want to discover that the document you want to work on doesn’t exist locally.

It especially shouldn’t be the case on a Mac – a device without built-in LTE. Sure, you can use your iPhone as a hotspot, and yes, that’s now extremely easy to do, but again, we don’t all live in a world where high-speed LTE is available anywhere anytime. It would be enormously frustrating to find that we simply can’t get access to the document we need until our plane lands.

Especially as Sierra doesn’t seem to apply too much intelligence to the business of deciding which files to offload. Here’s Jason Snell writing at Six Colors:

Here’s what happened: I was editing a podcast in Apple’s Logic Pro X, and my project was stored on the Desktop. All of a sudden, the voice of one of my podcast panelists simply vanished from the mix. I quit and re-launched Logic, only to be told that the file in question was missing. Sure enough, a visit to Finder revealed that Sierra had “optimized” my storage and removed that file from my local drive. I’ll grant you, the file was a couple of weeks old, and very large as most audio files are. But I was also actively using it within a Logic project. Apparently that didn’t count for anything?


The third problem, of course, is that Apple still – in 2016 – gives us just 5GB of free iCloud storage. That’s laughable for an iOS device, but absurd for a Mac. And you don’t even get 5GB per device: you can have an iPhone, an iPad, a MacBook and an iMac and you still get a grand total of … 5GB.

So the storage management features of Sierra aren’t really a free upgrade to your operating system, they are a sales tool for Apple to sell you paid iCloud storage tiers.

Now, I don’t mind paying for online storage. I have a 1TB Dropbox Pro account on which I store almost my entire Documents folder (chosen because I find it more reliable than iCloud), and I also have 50GB storage on iCloud. Combined, they come in at $11/month, and I don’t begrudge that at all. But I do worry that Apple thinks we have already reached an always-online world.

Sure, I’m an outlier in having 2TB of SSD storage on my heavily-modified 17-inch MacBook Pro, but Apple does of late seem to have realized there are people who want plenty of on-board storage. You can configure a MacBook Pro today with a 1TB SSD, and I’d been very much hoping that the upcoming expected upgrade will bump the machine up to 1TB as standard and 2TB as an option. The way Apple appears to be assuming we all have iCloud on tap makes me strongly suspect I’m going to be disappointed.

Personally, then, I made sure to switch off ‘Optimize Mac Storage’ for iCloud files on both my Macs, and I won’t be going anywhere near the ‘Store in iCloud’ option!

What about you? Will you use either of the two new options? Please take our poll, and let us know your thoughts in the comments.

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