What are you non-obvious, maybe strange usecases of Syncthing?

For example syncing the media library with your friend or maybe your entire /home/user folder between your PC and laptop?

I’d love to hear your ideas!

  • lemmyvore@feddit.nlEnglish
    1·
    7 months ago

    How does syncthing know what to upload to paperless watch dir if paperless keeps deleting the files after ingesting them?

    • zaphod@lemmy.caEnglish
      2·
      7 months ago

      That’d exactly what you want! When the file initially lands in the sync folder, Syncthing sends it to paperless. Paperless ingests it, deletes it, and it disappears from my phone, now stored in paperless. Exactly what I need.

      If I wanted the files to stay on the phone I’d set up the phone as Send Only and the paperless side as Recieved Only.

      • lemmyvore@feddit.nlEnglish
        1·
        7 months ago

        Oh you delete them from the phone too, ok that makes sense.

        I don’t delete them from the phone (because they’re also in a different app I used since before Paperless) so that’s a bit of a dilemma. I’ll have to think about it better.

        • zaphod@lemmy.caEnglish
          2·
          7 months ago

          Again, Syncthing supports one-way sync so allowing paperless to delete them and having that delete sync back to the phone is entirely optional.

          • lemmyvore@feddit.nlEnglish
            1·
            7 months ago

            I mean, how does Syncthing know not to copy a file again if it copied it once and paperless deleted it?

            • zaphod@lemmy.caEnglish
              2·
              7 months ago

              The client on the sender side (the phone) knows it sent the file. It doesn’t care if the receiver side changed or deleted it. It sent the file. Its job is done. That’s why the mode is called “Send Only”.

              Meanwhile the client on the receiver side (my NAS) never pushes changes back. It only responds to received sync instructions. That why the mode is called “Receive Only”.

              It’s… all pretty simple. Not sure where the confusion lies?

              • lemmyvore@feddit.nlEnglish
                2·
                7 months ago

                The phone sync client would have to remember all the files it ever sends, which could be thousands. I’ve never seen a sync client that works like that, they usually compare the files that are in the source and destination folders. If syncthing can do this that’s really interesting.

                • zaphod@lemmy.caEnglish
                  2·
                  7 months ago

                  No it doesn’t.

                  Syncthing only needs to remember the current state of the files/folders it’s syncing. Not everything it’s every sync’d.

                  It does that by either periodically scanning the filesystem to look for changes since it last scanned (based on the file creation and modification dates that are stored in the filesystem), or it registers with the operating system to receive events when files are created, modified, or deleted.

                  When Syncthing notices a create, update, or delete, it pushes those changes to the receiver and then updates it’s record of the filesystem state accordingly.

                  It also pushes whole files, not deltas. So it doesn’t care how the files changed, only that they did.

                  Even with hundreds of thousands of files to sync this is a relatively small amount of state as it’s just file paths and their create/modify dates.