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I’ve lost data from SyncThing. I had a holder called “backgrounds” full of jpgs on my PC. I set it up to mirror the parent of that folder to my Linux machine

I’ve lost data from SyncThing. I had a holder called “backgrounds” full of jpgs on my PC. I set it up to mirror the parent of that folder to my Linux machine and my Mac, and everything synced and was happy. I’m still not entirely sure what went wrong by at some point one of the devices decided the folder name should be “Backgrounds” with a capital B (certainly not a change I made) and then all nodes deleted all the files in this folder and then started streaming errors to the logs that they couldn’t replicate all the files in either backgrounds or Backgrounds because none of the online nodes had a copy. SyncThing is very handy, but not something I’d use as a backup solution.

hda2 5y ago
I'm having a hard time understanding how you lost data. Are you saying that nodes other than the one with the renamed folder are refusing to resync the renamed folder? And wouldn't the node with the renamed folder still have all your files? Can you explain further?
- jwalton 5y ago
  I found this a long time after it actually happened, and long after whatever logs from the actual event were gone. When I found it, all nodes claimed they were out of sync, and all of them were complaining that they wanted to sync the folder "Backgrounds" but that it didn't exist on any online node. None of the machines had a folder named "Backgrounds" or "backgrounds" anymore. I imagine what happened is that this was somehow related to the fact that the PC and Mac have case-insensitive file systems, and the Linux machine does not. Somehow one of these machines renamed the folder (I have no idea how this could have happened). I would hazard to guess that SyncThing on one of the nodes (probably Linux) decided it needed to delete the "backgrounds" folder because it no longer existed, and then sync the new "Backgrounds" folder. If deleting the "backgrounds" folder was synchronized back to the PC or Mac though, they would have also deleted the "Backgrounds" folder, since in case-insensitive-land, they're the same folder. I went digging through their github at the time to see if there was an issue about case sensitivity and didn't find anything that was relevant and open. I didn't have a lot to go on, and my attempts to recreate it failed at the time, so I didn't bother opening an issue. It's entirely possible my specific issue is fixed by now.

hda2 5y ago

I'm having a hard time understanding how you lost data. Are you saying that nodes other than the one with the renamed folder are refusing to resync the renamed folder? And wouldn't the node with the renamed folder still have all your files? Can you explain further?

jwalton 5y ago
I found this a long time after it actually happened, and long after whatever logs from the actual event were gone. When I found it, all nodes claimed they were out of sync, and all of them were complaining that they wanted to sync the folder "Backgrounds" but that it didn't exist on any online node. None of the machines had a folder named "Backgrounds" or "backgrounds" anymore. I imagine what happened is that this was somehow related to the fact that the PC and Mac have case-insensitive file systems, and the Linux machine does not. Somehow one of these machines renamed the folder (I have no idea how this could have happened). I would hazard to guess that SyncThing on one of the nodes (probably Linux) decided it needed to delete the "backgrounds" folder because it no longer existed, and then sync the new "Backgrounds" folder. If deleting the "backgrounds" folder was synchronized back to the PC or Mac though, they would have also deleted the "Backgrounds" folder, since in case-insensitive-land, they're the same folder. I went digging through their github at the time to see if there was an issue about case sensitivity and didn't find anything that was relevant and open. I didn't have a lot to go on, and my attempts to recreate it failed at the time, so I didn't bother opening an issue. It's entirely possible my specific issue is fixed by now.