Folder per store\Folder per game\Files

If there's no way to verify the files I tend to put them in an archive format that can be verified.

It comes with a huge database of save locations (plus you can add your own). So if you're the kind of person to have a lot of games installed at once, you can back the lot in a few clicks without having to hunt down each location per game. It also has custom cloud backups (eg, using Dropbox) or "Sync & Link" where it will create "live" symbolic links to DropBox / Google Drive, etc, that save directly to the cloud without requiring a Steam / Galaxy like client, aren't limited to any one service and work with anything (eg, physical discs, non-GOG DOS games, and source ports / emulators).

dedicated backup drive, one folder per game/release, alphabetical order

Each game in its own folder - onto a 4TB NAS, occasionally rsynced to a 4TB external hard drive.

As for the HDDs, it depends on type. If you want storage hdds, or nas hdds, or general use hdds. These are the cheaper end of the scale and are good for a one or two time write type backup and stick in storage. Do t know how they would fare under normal load. I personally like WD Red for most of my needs, though have various other makes as well.

Yeah, I am unsure if that has always been the case, but I noticed the same some years ago.

However, it may be that those USB HDDs are usually the slower 5400 RPM drives while the internal ones seem to be usually 7200 RPM, and also quite often those USB HDDs use SMR (shingled magnetic recording) which allows more space with less hardware, ie, cheaper to manufacture. The downside with SMR is that if you are writing high amounts of data to a SMR HDD, the data transfer speed will plummet as the cache becomes congested.

https://en.wikipedia.org/wiki/Shingled_magnetic_recording
https://arstechnica.com/gadgets/2020/04/caveat-emptor-smr-disks-are-being-submarined-into-unexpected-channels/

For now I keep using mainly internal HDDs sitting on an USB dock station, except for portability reasons also one or two 2.5" USB-powered HDDs (I have 5TB and older 2TB ones).

However I'd prefer buying slower 5400 RPM, CMR (= not SMR), internal HDDs as they'd probably run cooler. The two 8TB Seagate Ironwolf HDDs that I now have as my main backup hard drives become too hot in normal use (sitting in the USB HDD dock station), unless I direct a desk fan blowing air at them all the time.

I already killed one such 8TB Ironwolf with heat, fortunately I got a replacement for free. Only later it occurred to me the reason it died was the excessive heat, as I noticed later that some S.M.A.R.T.-utility was constantly warning about the high temperatures with those IronWolves. Maybe they stay cooler when inside a desktop PC or some NAS/RAID case as the metallic case acts as a heat sink for the HDDs. With a plastic USB dock station, I need to blow air at them with a fan all the time, to keep them cool. Otherwise they don't dissipate heat fast enough, even though they are in open air.

The problem is that at least here I don't seem to find big (over 8TB), 5400 RPM internal hard drives. They always seem to be the hotter 7200 RPM HDDs.

Yeah I've been thinking about doing that (and I could do it also in Linux with e.g. LVM)... but the problem is I mainly use USB with such archive HDDs. I am unsure if it is advisable or even possible to combine several USB HDDs together that way.

I keep thinking I'd really want to have a RAID setup, but then I check the prices for such RAID setups and the mere case (without any HDDs) seem to be quite pricy, compared to having a simple USB HDD dock station that I have now.

Plus, isn't it so that all the HDDs in the RAID setup have to be the same size? So if I made a RAID setup with five 2TB HDDs, then if I wanted to expand it, I'd need to replace all the five HDDs with bigger ones?

So for now I just have two 8TB HDDs sitting in the dock station, which are 1:1 copies of each other. If one of them dies, I replace it with a similar size or bigger HDD.

I just use gogrepo to fetch everything to my NAS/server for now (4.5TiB at the moment - about a fourth of my currently available space).

I'm working on a way to sort it automagically (using hard links, so as to not mess up gogrepo's file structure while not doubling the space requirement) as I can't be arsed to go through everything by hand, not to mention keeping it nice and clean after a few updates.

Well, if you do have hdds setup as one drive it can help write speeds as it writes to all at same time (so I am led to believe, I have no evidence).

I can definitely recommend raid devices. You can get internal cards for 20 or 30 pound. I highly compliment the terra master d500, be careful, you don’t want the c version which has 2+3, this is the one:
https://www.amazon.co.uk/TerraMaster-D5-300-External-Enclosure-Diskless/dp/B01KO03BBA/ref=sr_1_6?crid=34S6ACFHXIXM0&dchild=1&keywords=terramaster&qid=1596752431&sprefix=Terramaste%2Caps%2C149&sr=8-6

It’s a DAS (direct attached storage, so you connect via cable). You can put 2 or more drives in. Sure they should all be the same size, and if you want to add drives you need to recreate. So you could start with a couple of 8tbs and hen expand later on, but you would need to recreate when you expand. That version of raid is pretty quick, a full 12tb takes a day or so.

I agree it’s an expense, and as it’s only for part of the backup is maybe a bit wasted, but it’s nice and condensed, gives a nice safety net. So long as you have > 1 separate backup it’s a start. I would always say have one more, have one offsite, say another house. You ca split the year up to three backups then and if the worst happens and the house burns down, you always have one. I did look at tape backups, but for good ones it gets very expensive,

Do you copy from one to the other, or mirror them? Just thinking what happens is the copy corrupts both? Three would negate that as only two are live at once. Large periods of time between would help with possible viruses and encryption.

Why is that extra speed important for backups?

Please re-read. It is the internal storage I have in the machine that uses this not backup. Speed is of course not a main concern with backups.

They're rare, but do exist. Also see a 14 Gb version (at stores from here and on the manufacturer's site.

No mirroring. I keep one of them as my master where I operate (update and organize the archives), and from time to time I copy (or sync) everything to the other drive. Then I use that other drive as the master for awhile, while the other is idle until I sync everything to it.

(I don't actually keep them both on the HDD dock station all the time, but the idle HDD is disconnected when not in use.)

This is not a perfect solution but I feel it is quite flexible, simple and cheap. At least I understand what I am doing and when. :)

Only thing missing is that I'd really like to use some more advanced filesystem (like btrfs or OpenZFS) with my archive HDDs, as they can keep track all the time that there is no file corruption or such. Then I would have a peace of mind about my archives, without having do integrity checking manually with e.g. rhash, dvdsig or checking compressed files with 7-zip.
Thanks, I have to keep that in mind. I like on that Amazon page how they clearly state there the important bits, ie. that it is 5400 RPM and CMR. Those are the two most important things to me.

EDIT: I happened to find both that 12TB and 14TB HDD in one local store here, not the one which I normally use (which seems to carry only 7200rpm internal HDDs). I guess I need to change store then, if and when this becomes relevant (I am still fine with my current 2x 8TB HDDs, plenty of room left and they both still work fine).

What kind of setup are you going to have for the file server? Running 24/7 on a low power Raspberry Pi4 or such?

That sounds something I might go for. The only thing is that I am a laptop player so I prefer to keep my (GOG) game installers on a USB-powered 2.5" external hard drive that I can easily bring with my gaming laptop even if I e.g. go abroad for a month or to my summer cottage.

Sure I could possibly download the game installers also from elsewhere from my home file server... but then there is no real benefit compared to just downloading them from GOG servers. Or then I have some idle USB 2.5" HDD which I fill with at least some of my game installers if and when I go elsewhere and want to have most of my game installers with me...

EDIT: Well, actually, my Raspberry Pi 4 already acts as my personal file server, now that I think about it. I have my old 2TB 3.5" USB HDD connected to it (it acts as its main storage device, even the operating system is there, RPi4 merely boots from its internal SD card), and ssh server is enabled on it.

I haven't forwarded the SSH port on my NAT router though so I can SCP copy files to/from it only from my home network... but if I need to copy files from it outside my home, it is also running Teamviewer which also allows copying of files between two machines running Teamviewer, even without forwarding any ports in the router).

So the only thing missing is expanding the HDD capacity over 2TB. I need to check if there are any issues in e.g. just connecting several USB hard drives to the Raspberry Pi, and then combining them to a bigger "partition" (volume) with e.g. LVM. At least for the data partition, maybe I'd still keep the OS itself separate...

I am unsure how LVM behaves if a LVM volume (e.g. the /data-partition) consists of several USB hard drives, and I forget to connect or power on some of those USB hard drives while I boot up the system. Doesn't the LVM volume simply show up until all USB hard drives are online, or does the LVM volume become corrupted due to missing partitions, or what?