Building NAS and Installing Unraid

My Synology DS221j I bought in 2021 is outdated today. As Synology's most entry-level NAS, its performance today is barely able to support any applications beyond the Samba service, and it doesn't support Docker. Therefore, I decided to buy a new NAS. I had considered buying the Synology DS925+, but Synology's new 2025 models introduced a restriction that only allows the use of their own branded…