I have a ZFS RAIDZ2 array made of 6x 2TB disks with power on hours between 40,000 and 70,000. This is used just for data storage of photos and videos, not OS drives. Part of me is a bit concerned at those hours considering they’re a right old mix of desktop drives and old WD reds. I keep them on 24/7 so they’re not too stressed in terms of power cycles bit they have in the past been through a few RAID5 rebuilds.
Considering swapping to 2x ‘refurbed’ 12TB enterprise drives and running ZFS RAIDZ1. So even though they’d have a decent amount of hours on them, they’d be better quality drives and fewer disks means less change of any one failing (I have good backups).
The next time I have one of my current drives die I’m not feeling like staying with my current setup is worth it, so may as well change over now before it happens?
Also the 6x disks I have at the moment are really crammed in to my case in a hideous way, so from an aesthetic POV (not that I can actually seeing the solid case in a rack in the garage),it’ll be nicer.
Ultimately it’s a matter of personal choice and risk tolerance.
The Z1 will be simpler and have larger capacity, but if you have a drive fail you’ll need to quickly get it replaced or risk having to rebuild/restore if the mirror drive follows the first one to the grave.
Your Z2 setup right now can have two drives fail and still be online, and having a wider spread of power-on hours is usually a good thing in terms of failure probability.
I manage a large (14,000±) number of on-site RAID1 arrays in various environments and there is definitely a trend for drives shipped at the same time to fail at roughly the same time. It’s common enough that we often intentionally swap drives out before shipping a new unit to the customer site.
On my homelab, I’m much more tolerant of risk since I have trust in my 3-2-1 backup solution and if my NAS goes down it’s not going to substantially affect anything while I wait for a drive replacement.