I’m planning a local NAS system and wonder whether ST could also serve as a backup solution by just mirroring and incrementally updating files to an external hard drive which is connected to one of my computers.
Speciffically:
Would it be an issue if the drive would be offline for several weeks and only be connected from time to time to sync all file changes made in the meantime?
Why SyncThing at all?
It is already installed and an automated tool that needs no manual scheduling.
I don’t know if it works in larger intervals though.
While normally the word “backup” and “Syncthing” don’t play well together, in this particular case I would say “say”. In fact, this is exactly what I’ve been doing myself, having a separate external HDD that I only connect once a month in order to sync files onto it, then disconnect and leave offline in a drawer.
Just please keep in mind that you can’t sync files between local folders, so you will need to use a different Syncthing instance for that purpose. I personally use a portable Syncthing installation which is actually launched from the external drive itself. This allows me to connect the drive to basically any computer and sync the files from there (if needed).
The HDD will be connected to one of my computers while the NAS would serve as central “always-on” instance that collects and shares all the data. So yes, I will have two machines for that to sync all the files.
From my point of view I would simply add another path on the PC and then configure the NAS to send-only to that path (ext. drive). And as long as the USB config stays the same, the path should not change when plugging in the device a few weeks later.
So you would say that ST is also able to log changes for several weeks without issues and update everything flawlessly once the drive is reconnected to the system?
You are better off using a backup program instead, like for example restic. There are many benefits: Snapshots which allow you to go back in time, protection against ransomware under the right circumstances. And more.
Yes, absolutely no problem with that. However, as @martinleben mentioned above, there are more specialised backup tools if that’s what you’re looking for. For me, the use case is simply to have an emergency, offline copy of the most important data in case something tragic happens, e.g. ransomware encryption, etc. I don’t need any more advanced backup features, and this particular HDD is too small to store things like versions or snapshots anyway.
Just a quick comment, if you do decide to go this route, I would not rely on the path alone but rather hardcode the device/volume ID in the path. This will differ depending on the OS, e.g. in Windows instead of letters like D:\Folder you would use \\?\Volume{1b3b1146-4076-11e1-84aa-806e6f6e6963}\Folder, etc.
