I am mainly hosting Jellyfin, Nextcloud, and Audiobookself. The files for these services are currently stored on a 2TB HDD and I don’t want to lose them in case of a drive failure. I bought two 12TB HDDs because 2TB got tight and I thought I could add redundancy to my system, to prevent data loss due to a drive failure. I thought I would go with a RAID 2 (or another form of RAID?), but everyone on the internet says that RAID is not a backup. I am not sure if I need a backup. I just want to avoid losing my files when the disk fails.
How should I proceed? Should I use RAID2, or rsync the files every, let’s say, week? I don’t want to have another machine, so I would hook up the rsync target drive to the same machine as the rsync host drive! Rsyncing the files seems to be very cumbersome (also when using a cron job).
Raid can protect you from a single drive failure in case you need an “always on” setup. Even then, if the drives are identical, they can fail within days from each other. If you don’t have monitoring, you’ll lose everything before you can react. I feel that’s not your use case.
You need backup. You can use something like rsync or even better borg backup. Keep the backup offline and backup often. You’ll be safer that way.
Would also need hot plug drive support with an easy way to swap the drive for 100% online recovery, which consumer gear often doesnt have.