Uncommon Syncthing usecases

I've got a couple of Raspberry Pi Zero's that emulate a mass storage device (basically it acts like a USB drive) that I have connected to 3D printers and my wife's embroidery machine.

Instead of using it with a network share like in the link, I share the folder with SyncThing.

It's super convenient to not have to move a USB drive around and can just leave it connected and get the files on there seamlessly.

I use it to synchronise RetroArch save states across my devices - desktop PC, Android TV, and Android handheld.

Installation on phone from F-droid (Syncthing-fork) gives a 1-way share of your Camera to backup to PC whenever you get back home. That's my top usecase... Together with syncing KeePass database since long ago too.

I have a keepass database synced between a phone, desktop and a Raspberry Pi 1. The Pi just sits as an always-on server. I don't edit it on my phone. Here's my problem: when I edit something on my desktop and save it I invariably get a file conflict error and have to force the Pi to accept the new 'conflicted' file from my desktop. Any idea why? It's incredibly annoying!
- I think you need to set up database syncronization in keepass. I had this issue for a bit until I enabled this. Basically you set a copy that's synced with syncthing outside of your keepass folder, then another copy that keepass edits directly. Then you can set it up so that when it saves the database in keepass it will sync the edits in the one that's mirrored y syncthing.

I have a site to site VPN between my house and my mother's house. I keep a raspberry pi at her house with a 2TB drive running syncthing. My photo library and important documents sync to her house as an offsite backup in case my house ever burned to the ground.

as far as syncing files between PC and laptop, I would think ownCloud would be better suited for that.

as far as syncing files between PC and laptop, I would think ownCloud would be better suited for that.

The main purpose of Syncthing is syncing files between two or more computers and it does an excellent job of that.
- True, keeping a not-necessarily-synced repository of files is more own/nextcloud's thing.
I'm currently building the same setup, the long-term goal being a Crashplan-type solution (back when they had a feature where you could backup to your friend's devices).

Having a large family, there a many geographically distributed locations for us all to use.

As for OwnCloud, ST is far simpler to setup. Granted, it's not nearly as flexible. I do use it to keep all our laptops and phones "backed up" to a desktop that runs Crashplan and Backblaze.

Edit: With ST that VPN isn't even required. It will sync, encrypted, over most any connection.
Ok, why syncthing and not rsync? Also, duplication should not be threated as backup.
- ST has stupid-simple clients for every OS. Rsync doesn't (though it's more capable in my opinion).
- because synching runs all the time. any change that I make is nearly immediately updated offsite. and if you think that is my only backup of my photos, you would be wrong :-) This is only a "if I lost all my physical possessions" type backup, not an "oops, I am a dummy and deleted something I shouldn't have" backup. I have multiple snapshot backups and also run incremental backups every hour. Storage is so cheap any more that I don't hesitate to have 5 backups of the REALLY important stuff. Most of my server storage is also raid5 in case of hardware failure. I have pushover set up to check for disk failures and push alerts to my phone if one is ever detected.
- It can be if the off-site duplicate has automatic snapshots.

I don't know if these are uncommon but I have a few cool usecases besides the regular 1:1 folder syncing, maybe someone else finds them useful.

Also you should know that the way I have all of this setup is that I have a container that hosts a bunch of SMB Network drives and a syncthing container that stores all of the fodlers on that drive. Having them also easily accessible through smb is great when I just wanna quickly copy something or back the folders up.

So here are some of my maybe unorthodoz usecases :

Music - As a fan of offline music, I have it setup that music I acquire gets synced onto the server and re-encoded as opus through a script into a second folder which then through syncthing gets sent out my mobile devices. There I rather have smaller files than lossless quality. Said script also sorts the music into folders based on artist and album metadata.
I also sync my Newpipe Subscriptions between phones (unfortunately by manually exporting my settings and re-importing them)

I also used to have a setup that would sync Minecraft Bedrock and Stardew Valley saves between devices (where Windows and Android saves are compatible) but Android 11 introduced a stupid restriction that prevents synching from accessing the the saves are located on Android.

I have become quite invested in Logseq, noting down everything from terminal commands, to shopping lists and recipes. Syncing the .md files between my desktop, laptop phone and work pc with ST works amazing.

+1 Came here to say the same thing.

And if there's a conflict, well, you just end up with both files (rather than neither)

IMHO, I think the Logseq devs should forget about their sync - but I understand that they need something to attract funding...

Working for a sip provider.

We used syncthing to sync sound files between sip servers. Things like voicemail, call recordings, hold music, menu options.

Sending files from my phone to my laptop - just copy them to a special folder and boom, sent 😁

Using it in an enterprise environment?

While it may seem unusual to us, a major financial supporter of ST uses it just that way as a third party vendor/consulting service.
Yep, done that.

I mod my games on my PC and sync it to my SteamDeck. I also sync the save files back and fourth, to continue playing on different devices. Mostly non-steam games.

I also sync my eBook collection to my eink reader with syncthing.

Everything is also mirrored to my always-on NAS, so syncing always works.

Echoing other comments, my backup strategy for all our devices is: Syncthing to replicate data to my NAS, restic to generate encrypted backups, and then cron+rclone to offsite those backups to Google Drive.

I absolutely love this setup.

It works anywhere. Syncthing takes care of firewall punching and all that so whether I'm at home or on the road, I know the data is being replicated correctly.
It's immediate. Syncthing doesn't run on some schedule. It's constantly replicating so I know at minimum there's a copy of all my data if something catastrophic happens.
It's private, encrypted, and entirely in my control.
The setup is built of composable parts that can each be understood, modified, and debugged easily.

Normally I'm a little cautious about rolling my own infrastructure for something critical like backups, but this setup is so simple and robust that I just don't worry about it.

Other use cases I've come up with:

I use Paperless as a DMS. It has a watch folder for automatically ingesting documents. I set up Genius Scan + Syncthing on my phone, syncing scans to the Paperless drop folder, so I can scan from my phone and automatically upload to Paperless without any additional app. Just scan and off it goes.
For a while I was playing Subnautica on my Steam Deck and my gaming rig. Subnautica doesn't support the Steam Cloud so I used Syncthing to replicate the save data across my gaming devices.

Not particularly weird or outlandish, but of course I also use Syncthing to replicate my keepass database across devices as well.

I also have a personal wiki of Markdown notes that I sync between my laptop and phone using Syncthing.

Oh, and I use it to replicate my Calibre library between my laptop and my calibre-web server.

Basically it's my swiss army knife of "I have data over here, I need to get that data over there" and it's amazing!

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

Currently just use it for backing up KeePass and uni files across two laptops and a phone.

I think it would be fun to use it for storing DRM free games (like from GOG) and sharing them with friends. Create a big dump of games and share them with each other. Maybe even share save files in games where that's common.

For a while I was exchanging encrypted backups with a friend. An easy way to offside without granting shell accounts.

Ha, i have planted a few rasoberry pi zeros running just syncthing in a few relatives' places for that. I worry about a blackout damaging them, so i have a few. Syncthing is great, as soon as a backup is made, it whisks it off all over the place, amazing.

Sync (one-way) from our phones to an always on tablet in the house - the screensaver is a photo gallery so now we actually SEE those photos we take.

Just update the exclusion list (on the tablet) every now and again to ignore older photos (ie 2023-10*) and it keeps them fresh.

I use syncthing to sync the sysvol folder between my two samba ad domain controllers.

A folder for backgrounds, shared between gf and i.

We can change each other's currently active background.

Also, synchronization of game assets - i save a template, and it almost immediately becomes available in her game.