RAID is good (if one pays for it and makes it work). Backups are better (if they actually get done, and if they are actually usable for recovery). Backups + R

RAID is good (if one pays for it and makes it work). Backups are better (if they actually get done, and if they are actually usable for recovery). Backups + RAID is better yet. But OP asked for a particular set of things that do not have any direct relationship to the traditional concepts of either backups or RAID, and ZFS can provide that set of things using copies=2. It isn't for us to decide the value of this for them.