- The second cathegory of sync problems is caused by sharing folders inside already shared folders (and has no relation to Obsidian). I have the Obsidian folder shared N ↔ T ↔ M ↔ N. But I also have its superfolder Documents shared M ↔ T, and this is the cause.
In Sync a subfolder of an already synced folder - #3 by Alex, there’s a warning, but not a serious one. In fact it turns out, that in this case synchronization can cause a lot of conflicts and even more serious troubles. For instance:
2a. Files and even folders can disappear.
Scenario:
- i. I create a directory tree at T
- ii. ST replicates it to N
- iii. At N I validate it, if it is not good enough, I delete it.
- iv. The deletion is replicated back to T.
- v. At T I recreate a new version of the directory tree.
- vi. Now, the synchronization of the superfolder steps in, and replicates deletion of the directory from M.
The more serious situation may be when the M is disconnected for some time, and when it connects, it deletes the final version of the directory tree.
To prevent this, the Obsidian subfolder must be ignored in the synchronization of the Documents superfolder.
Conclusion
I think, there should be a more serious warning written somewhere, e.g. in FAQ - don’t do this, if you do not want to lose data.
There are also other problems that I haven’t analyzed yet to learn the cause.