Enough is enough.
After 10+ same accidents. This happened again - last nail to the Dropbox coffin. I'm the customer since 2011, paid 15 years of subscription and they refuse to fix the essential problem. I'm not risking this again, leaving to MEGA where this problem do not exist.
No matter what settings you turn on or off. Dropbox app without any confirmation within seconds easily remove 20GB+ of local data. So if for whatever reason Chrome gets crazy for a few seconds and eats up the entire remaining SSD space with some swap file (easily happens with some faulty extensions) - you just force quit the Chrome or turn it off. And the space is immediately recovered. No big deal.
BUT during this time - Dropbox literally take without your consent huge chunk of synced data and randomly remove it - instantly. So when you are on slow connection or travelling - you are completely screwed.
Now I desperately need some highly sensitive data and they all disappeared from my SSD to become online-only. Thousands of files, randomly gone. And only way to get the 20GB data back to the laptop when you are at the airport or travelling is to download all of it on some super slow connection on the other side of the world that will take 2 days. This is extreme and 100% unacceptable.
All the stupid excuses of the dropbox representatives or advices of wannabe smart "reddit" commenters are useless. Who is the power user knows exactly what I'm talking about.
The Dropbox settings menus are misleading. The global preference for "how to store new files" only applies to files synced down from other devices, not files already on your Mac. And it is still not reliable.
All the BS recommendations "Right-click and Make available offline." - This of course do not work. Dropbox app does whatever it wants anyway.
The core issue is Apple's forced macOS File Provider API. When Dropbox migrated to this architecture (moving your folder into ~/Library/CloudStorage), it handed control over file eviction to macOS. They could have find some workaround or safety net. But they didn't.
- Automatic Eviction: If macOS detects that your drive is critically low on space—exactly what happened when Chrome filled my drive with swap memory—the OS forces file caching daemons to offload files to the cloud. It does this even if you previously right-clicked the folder and selected "Make available offline".
- Explicit Tagging Requirement: According to Dropbox Support Guidance on File Provider, macOS will only respect the offline status if files are explicitly and individually marked as "Available Offline". Any files that were default-downloaded but not manually tagged are viewed by macOS as temporary cache and will be wiped instantly during a space crisis. - This is almost impossible to keep a track on, when you have tens of thousands of files or sub folders and constantly creating / changing them.
If you absolutely cannot risk being locked out of your files while traveling offline: the default Dropbox desktop app cannot be trusted on a nearly-full Mac drive. You have only option to permanently fix this:
1 Download everything you need.
2 Delete the Dropbox client.
3 Move the files to normal folder out of CloudStorage folder.
4 Your files are now standard local files, completely safe from background OS eviction.
5 Use MEGA to backup data. Since they do not comply with "macOS File Provider API".
I do not care about the solution or the why "macOS File Provider API" does this. It is Dropbox dev team failure, they could have find workaround already, since they know about this issue for years.
