I set the Full Rescan Interval (s) to 0 because I want Syncthing to rely only on filesystem events for syncing.
However, I still see it going into “Scanning” mode.
My drive is very large, and it seems that while Syncthing is scanning, new filesystem events either don’t propagate or the files aren’t transferring as expected.
If you mean scanning on startup, then no, it is not possible to disable that. This is a known issue (see below).
For the record, you will still see “scanning” when new changes are detected locally (when using file watching), but this won’t be a full scan of the folder.
I wasn’t talking about the first scan.
What I noticed is that new files did arrive on the drive, but Syncthing didn’t seem to pick up the filesystem events. In the UI it just showed “Scanning” with nothing happening for quite a while (around 30 minutes). Then, once the scan finally finished, it suddenly processed everything — I saw the percentages updating, and after that the sync was released and went back to normal.