I have a lot of backups. I have a small NAS but not big enough. I work (DSI) for the French National Education (EN) and I have a lot of .img discs to keep for colleges and high schools. + a lot of portables softwares that is no longer accessible or has disappeared. Of course, I have backups on external drives, but that's not enough. thanks for your advices
Mechanical HD is cheaper per TB, I'm not sure they are "more" reliable. They are also hotter, draw more power and make more noise.
For example a 860 EVO SATA 2.5" SSD 1TB costs $150 RRP. It has a 5-Year Limited Manufacturer's Warranty. The MTBF is 1.5 Million Hours <--- Thats 171 years. And can handle 1,500G. If it doesn't fail in the first week your looking at something that literally will not fail. You will die before it does.
For your data I'd recommend the old 321. 3 copies, 2 local and one offsite. Never maintain more than one data set at a time. I don't use different mediums.
I use a Synology NAS. Volume 1 is my data, Volume 2 is my local daily backup and hourly snapshots. Each night I then push a 2nd backup to Backblaze on their B2 Cloud. BackBlaze B2 is slow to recover but I'd only need it if my house burnt down. Synology has all the software as part of their DSM software. Yes, I use Ironwolf mechanical drives in my NAS because buying I'm buying multiple 8TB drives to raid. At the moment when you go above 12TB the price per TB really soars. Buy from ebay when they have specials.
Synology also has a app to throw on your desktop call Synology drive. You file all your files there and it syncs them back to your home directory on the NAS.
I wouldn't consider an HDD, as a minimum I strongly recommend a SATA SSD, preferably a Samsung, although there are other cheaper options. Besides what Legion said, an HDD is also very slow when transferring large amounts of data. Of course NVME would be better, but if you don't want to splash out, at least stick to a good SATA SSD.
Well in fact I had bought a sata DD to make backups of my data quite simply. I don't need speed, but stability. I opened the mini PC, seen how the interior is but to install 1TB sata (7mm high), nothing to do I don't know where to put it. Yes I saw the videos, yes I read the documentation etc. Please take care of your documentation: it is too sketchy. When I read in French (yes in addition it is badly translated): "Insert the HDD in the card at the bottom" ... I do not understand anything. Your manual is written in very small letters, you need a magnifying glass to read it. I am a computer system and network technician not hardware. Thank you.
For much less I should have bought a Raspberry Pi.