

In addition to other advice, with only hardware, have 1 cold spare drive for every 2 years of remaining life of the hardware. It gets difficult to find similar spec drives the older they get. So if you want to use the drives in the NAS for another 4 years, get 2 spares. After that you start getting into the territory of replacing the drives anyway.





Basic documentation does not equal open source.
Toaster ovens from 40 years ago did better. They came with a technical diagram.