> 4) mirror it to the cloud (unworkable, considering it's 16TB) sure? we faced almost the same scenario, but with incremental backups plus data deduplication w

> 4) mirror it to the cloud (unworkable, considering it's 16TB) sure? we faced almost the same scenario, but with incremental backups plus data deduplication we have two outside backups (with Borg and https://en.wikipedia.org/wiki/Proxmox_Backup_Server https://en.wikipedia.org/wiki/Proxmox_Backup_Server ) that are updated nightly (with a cheap internet connection) deduplication is really a must have for backups, plus encryption and read only, of course