I'm trying to get rsync working as a simple backup tool (well, to be honest, more of a synchronization tool). I'm running Ubuntu 14.04 on a SSD on my home NAS, with two 3TB SATA drives for storage. I just acquired two 3TB WD Elements external hard drives (USB2.0), and plan to synchronize (or back up, or update a snapshot; I'm not sure of the language) the NAS storage drives to the external drives once a week.
The command I'm using is as follows:
# rsync -av --force --ignore-errors --delete /media/Sea01 /media/n54l/804E-B550/BU
The problem I'm facing is that whenever I run it to sync to the BU directory, it seems to want to synchronize the entire drive all over again, instead of just update as per the latest changes (add the new files and directories, update the modified ones, and delete the ones no longer on the NAS).
I'd greatly appreciate any advice you may have. Also would appreciate pointers on a better rsync command as I'm somewhat green, so to speak.