I use Beyond Compare to sync files from my laptop to my NAS which is a QNAP (my laptop is Linux Mint). It is incredibly slow, to the point that it is driving me crazy. Admittedly, I have lots of large files on my laptop that I move around frequently, so that may just be how it is. I do have my laptop setup to sync to my phone with Syncthing, and it seems like my phone is always up-to-date and in sync with my laptop. But of course it is syncing in, I guess, “real time” as opposed to a Beyond Compare backup which does everything only when I tell it to when lots of changes have already been made at the end of the day. Is it possible to install Syncthing on QNAP? Perhaps that would make things a bit faster, although I’ve always had a hell of a time trying to install something that isn’t a proprietary app from their store. Anyway, any suggestions are welcome.
EDIT: Plugging into ethernet instead of syncing over wi-fi helps speed things up a bit, but not as much as I would like.
Yes maybe moving files could be an issue. Lot of software archives by path. rsync is one way but I suspect it is path based. If your using BTRFS I suspect the bulitin mirroring utility can track movement. Never tried though.
For backups as opposed to syncing Deja Dup, duplicity, or dupliciti are suppose to be efficient. Not sure if they are path or Inode based though for example. GNU Tar in some modes can track hard links but I do know if it can handle movement of files.