I thought I could effectively reproduce the dual RAID1 configuration, but I'm learning that you can only have parity drives in unRaid, as long as the drives are (combined) at least as large as the ...

I want to convert my existing QNAP NAS (TS-451D2) from QTS OS to unRAID. Help poke holes in my thought process here, or confirm that it's not a bad idea... Right now my 4-bay NAS has 2x4TB and 2x8TB.