> for redundancy and to prevent bit riot

What are you doing to your hard drives that the bits are rioting?

BTRFS / ZFS.

You both wrote "bit riot" but meant "bit rot", right?

I've been running a RAIDZ2 NAS (with ECC RAM) for like 5 years with no data loss/corruption issues. Are you saying if it was just regular RAIDZ there would be data integrity issues?