I have 8 4TB drives right now, 6 data, 2 raid backups using SnapRaid. I used a gui over it to create snapshots (elucidate i think). Never had to restore data thankfully. Did not want to mess with command lines. I also use DrivePool and configured some folders to duplicate. This setup is about 6 years old, maybe more.
I am about to move my data to 4 or 5 16TB WD Golds...2/2 data/raid or 3/2. Any suggestions for software raid to replace SnapRaid?
Well, first of all, raid is not a backup, it's about uptime. So keep separate backups if you need your data safe. As to raid, ZFS or MDRAID but i would go with ZFS raidz2 or RAID6 on that capacity.