3,2,1.
My nas is a Synology with raid.
- Backup with versions to a single large HD via USB. This ransomware protection or accidental deletion. (Rsync)
- Offsite copy to backblaze b2.One version. (Rsync) (~$6/month) This would be natual disaster protection. flood, fire.
- Second not raided cheaper Synology at a friends on the other coast. This has ~3 versions. Sorta the backup to the first two.
Maybe it's diff presented as versions? I use hyper backup on Synology.
Similar to these steps:
https://gist.github.com/mrl22/476d710fea63d71a770d0d44ca54325a