Warzone 2100 (you can download for free as it is an old PC game that went GPL)

gets more on the nose by the day

checksums at the filesystem level does nothing to protect against memory corruption which can overwrite everything on your disk with null values and a matching checksum; fail to write anything to disk and/or do nothing.

But that is the gamble you take every day with every GB of RAM you have.

the correct answer is Gemini or gopher.

No ECC, absolutely worthless for a NAS if you care about your data.

Raid stopped being optimal now that btrfs and ZFS exist.

If you plan on doing matching drives ZFS is recommended

If you expect mismatched disks, btrfs will work.

If you are most worried about stability get a computer with ECC memory.

If you are most worried about performance, use SSD drives.

If you want a bunch of storage for cheap, use spinning disks (unless you exceed the 100TB capacity range)

Your ZFS backup strategy should be to follow one of the following rulesets:

3-2-1 [3 copies of the data at 2 different locations for the 1 purpose of preserving the data]

4-3-2-1 [4 copies of the data at 3 different locations in 2 different types of media for the 1 purpose of preserving the data]

5-4-3-2-1 [5 copies of the data at 4 different locations across 3 different continents in 2 different types of media for the 1 purpose of preserving the data]

The details of the backup is more if you have a second system to enable ZFS send/receive or if you have to transport deltas from ZFS send