Is it possible to use USB HDD as a fake 'device'

Usually I backup files to my USB HDD , Is it possible to make syncthing backup files to USB HDD on the same host?
Thanks for help.

No

I’d disagree with Audrius here:

While syncthing will not do it in a straight forward way, it’s still doable. You can install “portable” syncthing on your USB HDD, and run it alongside your “normal” installation when you need it.

I do it with a portable HDD - it has it’s own portable SyncTrayzor (windows wrapper) installation on it, so I can always launch it and sync it’s contents with the main PC, whether it is the one currently attached or not. Be sure to pay attention to folder paths though, they need to be always consistent, and don’t unplug it before properly shutting down the portable instance.

Note: if you are always going to sync from the same PC and only when the HDD is connected to it directly, syncthing may not be the perfect tool for it then, you can use something simpler that copies stuff directly (like FreeFileSync)

Thanks for the reply!