One ZFS drive per pool, with unraid on top? Should be mostly fine. As you say these drives are terrible for writes, but they should be pretty reliable and performant for your workload.
Data Hoarder
We are digital librarians. Among us are represented the various reasons to keep data -- legal requirements, competitive requirements, uncertainty of permanence of cloud services, distaste for transmitting your data externally (e.g. government or corporate espionage), cultural and familial archivists, internet collapse preppers, and people who do it themselves so they're sure it's done right. Everyone has their reasons for curating the data they have decided to keep (either forever or For A Damn Long Time (tm) ). Along the way we have sought out like-minded individuals to exchange strategies, war stories, and cautionary tales of failures.
I would do a single ZFS pool with the three drives.
Electric is 35 cents per kWh here
I would do a single ZFS pool with the three drives.
that would be ideal
So if you have 6 SAS drives running 24/7 the turnover point from this investement would be at roughly 5 years. IMO not worth it at all.
what's the actual question?
Any downsides or pitfalls I should be aware of before I spend a grand? I know the drives are not stellar for write performance past a point. I know unraid supports trim in pools as well.
Okay, have fun?