Not everyone can afford to rent a warehouse. =P

FTFY

I didn't convert The Witcher 3 to punch cards yet! :)

You may look at git-annex for some help. I am using it to manage my media library across two HDD and I always get a full view of my collection. Plus, a cool feature would be applying game tags and then browsing it for 2001/RPG/FPP. :-)

That is a nice link. I find that NAS systems are quite expensive, even without storage. I'm thinking of building my own less fancy thing using a Raspberry Pi.
How much do those AMD NAS cost?

Take a look at ASRock QC5000 or Biostar A68N-5000. They are sufficient to build a 25-30W system.

Those may not be easy to find over here, but do look nice. Thank you.

Well, basically any recent all-in-one system will do. The case can be found for $20-30, if power supply in your region is sufficiently stable, no extra PSU is needed, otherwise check jonnyguru.com. You could and should go with ECC memory if possible. I know that all AMD solutions from ASUS support it on desktop. Others need to be manually checked. NAS is just some lower-power machine (not necessary x86, could also go arm) with platters. The ready-to-buy NAS are usually locked down and crappy on security, lack flexibility or have issues with recovery.

But ECC is so much more expensive! (And slower).

ECC is neither expensive nor slow. I am running 12 GB of it, for $40.

Last time I looked for it (about 6 years ago), that was the impression I got.
My usual store does not even carry it. I can find some 16GB around thd 80-90€ mark (~ $100), and 8GB for almost that much.

I'm glad you can find so many neat stuff where you live. It seems the hardware market in Portugal is not as varied. :-(

Ok, let me make you an expert in an instant.

For DDR2/3 there are basically three sorts of RAM:
1) unbuffered non-ECC, aka regular RAM without any checking. The suffix is "-U", like PC3-10600U. Motherboards using this RAM are also fully compatible and accept (2), but ECC functionality may remain disabled.

2) unbuffered non-registered ECC, aka unbuffered ECC. The suffix is "-E", like PC3-10600E. Motherboard should support it, CPU must support it, BIOS/UEFI must support it. 1+2+3=ECC on. This is usually seen in one-processor (1P) systems - aka "regular desktop/notebook etc mainboards" provided 1+2+3 meet, but there can be exceptions. Motherboards using this RAM are also fully compatible with and accept (1). It costs vary and are typically same as (1).

3) registered ECC, aka "server RAM" (not always the case). The suffix is "-R" , like PC3-10600R.
This is typically used for multiprocessor (2P/4P etc) systems, although it may also appear on 1P systems (!). The difference between (2) and (3) is that (3) has extra buffering to reduce stress on the memory controller, thus this RAM type may have a little more latency. This RAM is physically incompatible with (1) and (2). These may cost a bit more, but it varies - its nothing but a market price.

Thats it. Running Supermicro x8sti right now with 12GB of (2) in a desktop system with desktop components.

As for places where to purchase - one good option is ebay.

Regarding advantage of ECC, it depends ... maybe you get 1-2 bit-flips in half year due to cosmic radiation? Which may cause OS issues or something less. Maybe a bit of data corruption, but that is very unlikely (aka "possible"). So I would definitely get it for the server of any type, but its less important compared to other stuff like good thermal room, good cables, good PSU etc.


Edit: typo

Thank you for taking some of your time to educate me. Still, "Kingston 16GB HyperX Fury DDR4 2133Mhz CL14 - HX421C14FBK2/16" does not help me understand what kind of RAM it is. I only know that it is 2×8GB.

Also, if anyone wants to learn a bit more about the subject, you may read Google's paper "DRAM Errors in the Wild: A Large-Scale Field Study".

Its DDR4, I haven't dealt with this yet. But I know one thing for sure - its advertized "CRC on Write" feature is actually due to higher error rate, so it does not get any better from regular pre-4 RAM and is actually supposed to complement ECC in -R/-E DDR4 modules.