That's an interesting project. Would part of your plan include replicating your data offsite? Or are you just looking at it for bitrot / data loss prevention?
Interesting to hear that LumaForge is doing similar to me with two groups of 10-disk raidz2 vdevs. That is an optimal config to spread writes across the drives so good to hear they're doing that.Saw this yesterday on LTT:
My m.2 SATA games SSD is a WD Blue and I've got no complaints. I chose it for price (caught a sale) and decent benchmark numbers for a SATA drive for the price. It does what I need it to but I'll be honest in that I have a tendency to install stuff and just leave it, so I don't have a ton of write cycles on it especially since my swap file is on my NVME boot SSD
You are using the M.2 SATA for the NAS I/O buffer or what?