Just a quick update on this build.
After researching a bit more and reading through hundreds of replies in this forum, I see that there are already a couple of other posts on the topic to use the usual HP SFF and add a DAS. If anyone else comes across this and is curious, here is a links:
https://forums.serverbuilds.net/t/sff-nas-plex-server-w-das/4735
In my case, I have decided to go with a mini-ITX build based on the Node 304. Why? The case is exactly the size I can fit into my custom ‘server nook’ in my new garage. I also like that I can upgrade the system if I need to later and it’s all in one box.
So far I have found the Node 304 case (broken fan switch, but I will replace that with a cheap alternative) and a used 650W EVGA Gold ATX PSU (it’s more powerful than I need right now, but it’s efficient, runs without the fan most of the time and should last a very long time). As mentioned, I’m in NZ and can’t be too picky when deals are coming up.
I’ve tested a Gigabyte H170N-Wifi board, it’s a great fit with with dual NICs, 6 SATA connection and a M.2 MVNE slot and came with an i5-6400T. Unfortunately one of the ethernet ports seem damaged and after a weekend of troubleshooting I gave up and will return the motherboard now. Also, 4 of the SATA ports are part of the SATA Express connector and are 90 degrees angled which is a very tight fit in this case.
I really like Unraid and after some performance testing I’m convinced that my past troubles were solely related to my beginner use of an USB enclosure limiting I/O, so I’ll put this down as learning and move on.
In the few days since I set up Unraid I now convinced myself that I’d like more VMs (on top of the 20 dockers I run), so I’m looking at more performance.
Seems the ASRock boards are recommended a lot here, and the Z390M ITX/ac ticks all the boxes for me. I can go to 64GB RAM and upgrade up to an i9-9900 if need be.
That’s likely another post when I get to build this properly.