Let’s say, I want to re-install the OS on one of my devices.
I want either be able to preserve a device as is migrating it with ease, or re-create it and re-set it up reusing its name/label. Meaning, I don’t want that the old device to remain dangling.
One option is to purge the device that’s going thru an OS refresh from all other connected devices and then re-add the upgraded device from scratch, which could be tedious depending on the number of sync folders and devices involved.
Another option is to back up the Syncthing configuration before wiping the device for the OS refresh and then restore the Syncthing configuration afterwards. For details regarding the default configuration locations on Linux, macOS and Windows, see the Syncthing Configuration page of the official documentation.
If, for some reason, I were to forget to do any of these 2 options, would I be able to remove a dangling device from the list of “the connected devices” of other ones afterwards? Meaning, one by one, from each one.
I see that yes: Edit → Delete. Right? But would I be able to re-use its original label/name, with no issues?
Yes, on the other devices Syncthing’s UI will temporarily show that the missing device is “Disconnected (Inactive)” until the old device entry is deleted.
Yes, the label/name is just for user-friendly convenience. A new 64-character device ID will be auto-generated when adding the device back into service.