I have been thinking about building a NAS for years. Two weeks ago I bought the 7th generation HP Microserver. It has an AMD processor, 4GB of RAM and space for four hard drives. It also has a slot for a CD/DVD drive, which I found completely useless. The first thing I did was to 3D print a "reduction" for another drive to fit into that bay. It fits absolutely perfectly, there are pins that fit exactly into the holes for the screws in the HDD and then you are able to push it onto the shaft. The server now has 5 HDDs, 1TB each. So one should be for system and unimportant stuff, and the other four I have joined to RAIDz2, so I have 2Tb of space for my data. The main purpose for this server is to store family photos, videos and other documents, so I think the space is big enough. I installed TrueNAS and configured everything I wanted. After some research I set it up to connect via SMB and it worked. However, after copying about 5GB of data at standard speed, it then dropped to cca 100-300 kb/s. I have tried rebooting the server, rebooting the router, rebooting my PC but nothing has changed. I have almost no deep knowledge about how it works, but I found out that I have installed the system on one of the drives which is in the original bay, and the HDD in the CD/DVD bay is part of the RAID, so I will do another installation to fit the system on that drive, and then set up the RAID on the drives in the original four bays. Hope this helps, but I will see. Another thing I did was set up a Wireguard server on my VPN, so I should be able to connect to my home-hosted NAS from anywhere. The test setup worked, so hopefully I'll be able to set it up again after reinstalling.
Jan "Jenkings" Škoda - blog
Simplifying IT, Amplifying Knowledge