So another update from me, because sometimes things go slow. I've booted a #NixOS live image and the #badblocks program is running a check of my four 4TB drives (been running for 86 hrs and done 84% I think the last time I checked).
I did change my decision to use #NILFS2 & #RAID6. After deliberate consideration I've switched my choice to #ZFS with #RAID10.
— no longer NILFS2 because it doesn't have compression and ZFS even includes the kitchen sink
- 1/2
So after more reading tonight for my *BACKUP* server (that will be its main purpose) I have decided to:
— create a 4 disk #RAID6 array with #mdadm
— have it use #NILFS2 as its file system (with continual #checkpoints and manual #snapshots)
— use @nixos_org as OS
I understand it have a performance hit, from both these decisions, but this will be the biggest part in my backup strategy.
TBD:
— filesystem for OS on SSD 
I should really make an effort to journal and "blog" about the things I am reading in my spare time, so here is "Day 2" in a nutshell:
I read how #NILFS2 works, but most of the articles I've read are almost a decade old. It isn't the fastest filesystem around, but for my backup server it is actually quite ideal with its continual #checkpoint (and convertible to #snapshots)
Everything I've read say that it is actually a quite simple #filesystem; it just stores files! It doesn't - 1/2
Chris 
