Synching between two drives

hi, newbie here

i mainly wanted my files to upload to my ssd that's connected to my router, and then after files have been uploaded, i wanted that router to automatically move those files to my hdd on my router, i've searched online on how to do it but kinda got lost and now a bit of a detailed instruction would help me a lot, thanks

Rsync perhaps?

Or maybe syncthing? But, it's a little heavier weight than rsync and requires installation on all the involved devices. On the other hand, once it's set up, it just works and you don't have to worry about cron jobs and any tooling around it.

I've been using it on a couple RT3200s for a couple years and it has worked without issues. I just checked and its resident memory footprint there is 1.2MB (of 512 on the RT3200). Mine is syncing between all of router, NAS, main server, several workstations, an rpi, a couple android phones, a couple of windows laptops. Sister's RT3200 syncs to her macbook.

okay.. will try and let you know

can i set a fixed routine on rsync? really dont know that much about it

No, rsync is basically a very fancy version of cp that does across-network optimization (diffing files to see if they need to copy, compressing those that are copied and stuff like that). That's what I meant by "tooling", you need to manually run it, or set up cron jobs to fire it off, whenever you want your file transfers to happen.

Syncthing runs as a demon, watching for file changes on specific directories that you point it to, and copies the files between hosts whenever they are changed. If you're familiar with Dropbox or Microsoft OneDrive, it works like that, but with more configuration options, and without any cloud connection (just between the machines you've got it running on).