Folder ID : what does it do?


#1

I am new to Syncthing and still very much playing with the various features while going through the documentation. One topic I could not find much information on is the Folder ID. Should Folder IDs be kept secret? Is a long, random Folder ID better than a short memorable one? Does the Folder ID have anything to do with how data is encrypted on transfer between devices? Any information for understanding Folder ID is welcome.


(Audrius Butkevicius) #2

No, folder id is just an identifier that only matters between trusted devices.


#3

So both Device ID as well as Folder ID are just identifiers.

However, device ID is generated by Syncthing, whereas Forlder ID can be set by user.

Is there a recommendation for the format of the Folder ID? I noticed two five digit blocks separated with a colon seem to be standard. Would “mysharedfolder” be an aceptable Folder ID? What happens if the Folder ID is not unique and some other device is syncing a different folder with the same Folder ID?


(Audrius Butkevicius) #4

Folder id can be whatever you like. It’s random these days to prevent collisions, so all of your phones don’t just have a Camera folder id.

Device id is a bit more tricky, as it can be used to track your ip addresses over time, but there is no risk of making it public other than getting unwanted connections.


#5

In that case, the data of both folders will be merged as soon as your device shares the folder with the other device.

That’s exactly why we added a folder label and generate the folder ID nowadays.


#6

OK, so Folder ID is just an identifier, it can have any value/name, but needs to be unique among all connected devices. It’s best to just use the default value/name, as there is nothing to be gained from changing the ID.

Many thanks for the explanations!


(Audrius Butkevicius) #7

It needs to be the same on two machines if the dataset in question is the same, as otherwise it’s just two separate datasets.


#8

Needs to be the unique for each dataset shared between connected devices.

Edit: Folder ID is just an identifier, it can have any value/name, but needs to be unique for each dataset (shared folder) among all connected devices. It’s best to just use the default value/name, as there is nothing to be gained from changing the ID.