I divide stuff into 3 categories: Stuff I kept but can loose (old versions of installers, stuff I can find on the web if I need it back, etc.), stuff I'd rather

I divide stuff into 3 categories: Stuff I kept but can loose (old versions of installers, stuff I can find on the web if I need it back, etc.), stuff I'd rather not loose but it wouldn't be the end of the world (media files), and stuff I can't loose (legal doco, family photos, email archives, etc). I've got about 20TB split over 2 FreeNAS/ZFS NASs, mostly as RAIDZ, but I do have a 4TB RAIDZ2 zpool. I've also got a cloud backup space. Stuff I can loose just finds a space on one of the servers, stuff I'd rather not loose is shapshotted between the servers periodically, and stuff I can't loose goes to the RAIDZ2, is snapshotted between the servers and also sent to the cloud. Once you go through the pain of deciding what bucket everything goes in and creating the ZFS filesystems for them, it's pretty smooth and I've found it to be a good compromise between the risk of loosing something critical and the cost of redundancy for everything. And, to be a little old school, I have a DLT that I put the really, really can't loose data on which get's put in the safety deposit box periodically.