Some Dropbox and Mylio users are reporting missing files after turning on a new iCloud feature in macOS Sierra (10.12). The feature is called Optimize Mac Storage, and was added to Apple’s new desktop operating system to help people use iCloud to free up space when their local disks are approaching full. When turned on, iCloud will attempt to keep all files you’ve indicated need mirroring on your local machine backed up on iCloud. Pretty straightforward. Then, if space on your local machine starts running out, iCloud will remove older, lesser-used files from your local machine, leaving only the copies of those files stored in iCloud — the files that were on your local machine are replaced with an iCloud ‘stub’ or reference file (basically, a wayfinding placeholder. Or an IOU).
The trouble comes when 3rd-party replication systems — like Dropbox or Mylio — are set up on Sierra machines with Optimize Mac Storage enabled. Because iCloud may delete local files synced with Dropbox or Mylio, leaving only the iCloud reference file. Which isn’t happiness if you go to your Dropbox or Mylio directories and find only iCloud IOUs.
Yikes! Is this a first shot across the bow in a Cloud War?
Here’s What to Look For in Dropbox
Dropbox users have complained about strange error messages, unusual icons in Dropbox-synced folders, and data loss.
“We do not currently support a configuration where both iCloud and Dropbox sync the same files,” says the Dropbox support support article on iCloud’s Optimized Storage, “iCloud may remove local copies of files and replace them with stub files (.icloud).” This change would get replicated to all Dropbox synced devices, including their website browser.
Read the full Dropbox support article here.
Here’s What to Look for in Mylio
A similar situation can be true in Mylio, where files in your library get replaced by pointers that Mylio doesn’t recognize, and that change is pushed to all other devices managed by your Mylio account. From the Mylio Support website:
“At this time, it is recommended that you do not use Apple’s Storage Optimization features in conjunction with Mylio as it can cause apparent data loss (though not actual data loss as your photos are in iCloud). We are investigating resolutions for this in future versions.”
Read the full Mylio support article here.
How To Turn Off iCloud’s Optimize Mac Storage on macOS Sierra
- On your mac, Open Settings > iCloud.
- In the iCloud Drive line, click Options.
- In iCloud Drive Options, uncheck the Optimize Mac Storage checkbox.