[rincebrain]

How have you found syncthing's scaling?

I've been trying to use it for a massive tree of ~250k files across ~500k folders, which only needs to live on one device at a time and sync to a backup in case it dies, and even if I tell it send-only/receive-only explicitly, it regularly seems to go cross-eyed at some change made in the folder structure and give up and rescan and hash everything, and if anything in the tree changes while that's happening, it gives up and just marks it a conflict to be manually resolved...or silently hangs until I restart it.

[caconym_]

It's working well for me (as in totally hands off for months or even years at a time) at (I think, roughly) a few hundred thousand files but probably significantly fewer directories. Overall I'm really impressed and happy with it. But this is just personal file sync, nothing too demanding and unlikely to hit edge cases with concurrent edits etc.

[hiq]

On which operating system? That wouldn't surprise me on Android, a bit more on other platforms (and worth filing an issue).