Last week, Microsoft rolled out a new build of its Windows 10 Technical Preview. In its release notes, the Windows team noted that Windows' integrated support for Microsoft's OneDrive cloud-hosted sync service was changing so that "starting with this build, OneDrive will use selective sync."
In Windows 8.1, OneDrive integration meant that files could be stored locally or on Microsoft's OneDrive service, with cloud files either kept on OneDrive until needed or synchronized between PC and cloud. Placeholder files on your PC (aka smart files) showed details of cloud files, letting any application open them -- and Windows index them. As far as you were concerned, there was no difference between local files and OneDrive files.
The changes in the latest Windows 10 build turned out to be more significant than the initial description. Smart files are going away in Windows 10, along with the ability to see what was stored in a OneDrive folder without using the Web application. Sync will be an all-or-nothing process: You'll sync a folder between a PC and the cloud, or leave it on OneDrive.
People were getting confused by smart files, Microsoft said, and were trying to open them when they weren't connected to the Internet. The result was an angry online protest.
Give us back our smart files!
Thousands voted for the return of the Windows 8.1 OneDrive integration on the Microsoft Windows Insider program's UserVoice page, many of them posting angry comments. A response from OneDrive program manager Jason Moore failed to quell the outrage, with Microsoft staying the course.
Explaining the decision, Moore shared more of what Microsoft was aiming for with the changes, introducing Windows 10's new OneDrive synchronization engine, and describing a possible future OneDrive integration that mixed some of the Windows 8.1 features with a more cloud-centric way of working.
Why has Microsoft made the decision it has, and why are users so upset?
While smart files could lead to confusion, Microsoft is addressing a deeper technical issue with these changes. OneDrive's Windows 8.1 incarnation was designed in simpler days, when users had 15GB of cloud storage. Microsoft's latest sally in the ongoing cloud pricing wars with Amazon and Google changed that, with the introduction (in 10TB tranches) of unlimited cloud storage for its Office 365 customers; customers who'd only seen their 15GB cap raised to 1TB. The Windows OneDrive client had rapidly become decoupled from its linked cloud service.
Key issues: Space, bandwidth, and compatibility
With users uploading terabytes of data into OneDrive, smart files suddenly became a different problem -- especially with the arrival of a new generation of low-cost PCs. Designed to compete with Google's Chromebooks by taking advantage of the cloud rather than local disk space, they cut costs by cutting storage.
Having a $99 tablet or $199 laptop with merely 16GB or 32GB of local storage doesn't seem like much of a limitation when you're able to work with terabytes of data in the cloud. But it is an issue when each file in the cloud has its own smart file shadow on your tiny solid-state drive.
For example, a 3.5MB JPEG image in the cloud has a 30KB smart file on a PC. Looking at my own usage shows the scale of the problem: a 5,000-image synced phone camera roll uses 7GB on OneDrive, but with smart files it casts a 200MB shadow on my laptop's drive. As more and more files moved to the cloud, users would quickly find their cheap devices overwhelmed.
There are other problems, too. While Office apps save to OneDrive, with a slow connection over hotel Wi-Fi, files can fail to open. Then there are the sync issues caused by uploads from different machines that can't be reconciled by the OneDrive service, resulting in several versions of the same file with different names.
Third-party applications can also have problems with smart files, using file system calls that attempt to open the local placeholder rather than triggering a download from OneDrive. It all adds up to one conclusion: While Windows 8.1's OneDrive integration works much of the time, enough edge cases make it impossible for Windows 10 to continue to work the same way as Windows 8.1.
Phase one of a OneDrive rethink
OneDrive's client desperately needs an overhaul, and a new Windows release is the place to make the needed changes.
It's essential for Microsoft to fix the way local applications work with cloud content, so it can give its users the promised benefits of cloud-scale services such as Office 365's machine-learning-powered Office Graph. It also needs to find a way of supporting devices with very little disk space -- as well as building a service that works with everything from the Internet of things to phones and beyond.
That's a tall order, and it means tearing down Windows' cloud synchronization methods and starting from scratch. What we're getting in the latest Windows 10 build is the first iteration of a whole new synchronization engine designed to support a future OneDrive service that merges the consumer OneDrive and the enterprise OneDrive for Business.
How it's going to work in the final Windows 10 is still unclear – and what we have in the current build is an early look at a service that's very much a work in progress, both on the PC and in the cloud. We're getting some functionality now, but it's meant losing the features users came to rely on in Windows 8.1.
Part of the problem comes from the choice of phrasing in the initial announcement. To most users "selective sync" means "if I select it, it will sync," not "only the selected directories will sync." The file sync world has its own language that describes the granularity of the synchronization method being used, but that language doesn't map to what users understand.
If Microsoft had clearly stated what was happening and, above all, why, things might have gone very differently. If it had also clearly articulated a road map -- from the Technical Preview's Dropbox-like functionality to a cloud-hosted index that would still allow users to search for files to an eventual return of a more easily understood form of placeholder -- users would have been more understanding.
If there's a lesson to be learned here, it's that it's hard to make changes that affect the way people work without a lot of explanation and preparation. If Microsoft had explained what it was planning and why in advance of announcing a new Windows 10 build, it probably would have avoided the resulting uproar.
But there's a lesson here for its Windows Insiders too: Windows 10 is not a design-by-committee operating system. User feedback is welcome, but Redmond still calls the engineering shots.