I will not say what backup I have atm because I basically have none.
Instead I will write my take on how I plan on doing it and what I suggest to you all.
This will be in few parts as GOG has char and rate limiting.
First of all, you should EXACTLY calculate how much it's going to take. NOT "roughly". Be exact or you will regret it sooner or later. Go and count every single file you are interested in backing up. Those 1-10 MiB files too.
Those small files (below 1 GiB, with median being probably below 50 MiB) alone were total of around 20 GiB for me.
I made fairly accurate (not 100%) draft estimate after seeing the "EGS GOG deal" thread.
(I spent "large amount of time" and manually calculated total by taking ALL files into consideration with their exact GOG reported sizes)
My results were:
I have 87 library positions right now.
If I would go and download EVERY single file (that assumes 1.ONLY English installers 2.Only latest collective versions) it would take around 647 GiB.
Out of those 87 I have PAID for 33 GAMES (around 36 or so positions in library).
Rest is demos, "goodie packs" (not to be confused with extras), and stuff obtained for free (purchase bonuses, stuff free on store, things from giveaways).
I use Linux as my primary system (for gaming too) and will do so eternally (well at least I will use *NIX derivative, because I may MAYBE consider BSD someday).
So that means that I care about A.Linux ports B.Windows ports (even if there is a Linux port available).
I never saw Mac as a viable gaming platform, I didn't ever own Mac and never will (for very good reasons, that company is BS) so ports for that platform are not in my interest AT ALL.
So removing Mac ports from total makes it slimmer by about 124 GiB. And should I even care about them then only about 24 GiB is for stuff that I actually paid for.
I have spent less than 140 eur on this platform in 5 years I am here.
It's not terribly a lot but I am pretty poor so I don't want to have this go to waste.
And I do own quite some games here that I don't own elsewhere.
So at the very least I need to backup the stuff I paid for.
The 600-ish GiB of data isn't terribly lot PER SE.
But it gets super inconvenient in the long run. Namely:
1.My internet is ancient and atrocious. If it works FINE I can download around 50 GiB per day IF I would do nothing but download for entire day. And that is IF it works. Upload speed is a complete joke and so Cloud storage is a big NO (I have top of like 0.4 Mbps upload. Also having 500+ GiB of Cloud storage is REALLY expensive with NO guarantee of it working in case of some "major world events").
2.We are not yet in "40 TiB drives popular on the market" situation so no matter how you look at it with time it means having to put up with a stash of drives instead of for example single one (or few at best, for safety and redundancy).
3.Platter based hard drives are a burden. They need replacement every few years. Even with enterprise class you are still going to have to throw them out of the window after 10 years max.
4.Ssd drives are a different burden. Suspectible to solar flares, degausing (most don't even come in metal cases, let alone have any shielding), memory cells demagnetising over time when not connected to power for many months. TLDR they need maintenance at least once a year even if totally unused. Plus they are still too expensive.
5.Flashdrives. Overpriced. Quality is generally worthless. Generally the worth they represent is temporary just like the files stores on them longterm. (it adds to the insult that close to nobody sells MLC ones nowadays)
6.Optical storage is prone to physical damage. So right off the bat it filters off all normal grade disks.
DVD can be obtained in "better" quality but it's still trash longetivity compared to BD.
7.The 100 GiB BD disks are not cost effective yet. 50 GiB ones are unjistifiably price gouged (btw pressing BD at factory costs basically same as DVD just so you know, so it's not like it costs manufacteur more). 128 GiB are close to unseen (and EVEN MORE price gouged) on the market. BD disks above 128 GiB (they DO EXIST) are not currently available on the market which adds to the insult (and alleged prototype 1 TiB BD disks would allegedly require different laser wave length so could not be used without replacing drive which adds to the cost).
Storing even as much as 1 TiB more data PERMANENTLY is troublesome these days.
We are progressing technology and storage but Cloud storage prices don't go down (because of some responsible people's greed).
So naturally it would be desired for me to reduce the size of this backup as much as possible.
Right off the bat I am "ASSUMING" that the files in question cannot be further compressed.
I don't know that. But I'd rather to prepare for "raw dump" and have more free space in case I manage to compress it instead of underestimating and getting into dissappointment and trouble.
IF I would be to compress the files I would likely TRY to use ZSTD (on custom settings).
So I started flexing the math and figured:
-"witcher goodie pack" is a whopping 45 GiB and I am not very interested in these games so I am likely to drop it
-the Mac ports drop 124 GiB off the total
-Linux ports (including EVERYTHING, not just the stuff I paid for) weight around 94 GiB
-all possible extras (including stuff I didn't pay for) weight around 32 GiB
-cyberpunk goodie pack weights almost 8 GiB
-free stuff (INCLUDING their mac ports) is around 302 GiB (that includes Shadow Warrior 2, Everspace and Witcher 1 among other things)
-demos (including their mac ports) are around 15 GiB, not a whole lot but not great (and it's not like I saved every possible demo to my library)
Removing mac ports, "cdpr marketing tr**h", free stuff and demos it goes down to around 254 GiB.
That is a TOTAL MINIMUM I have to backup.
I generally don't care about demos (and should I want them they would fit on 3 DVD) in this case. They are most useful as benchmarks if anything and since they "should" remain free this isn't much of a concern.
I want all extras for games I paid for. Period. I will not pick as that could lead to a regret years later.
Free stuff is not a direct financial loss so it's not a priority.
But there are some I do care about so there is unknown amount for that.
I haven't calculated yet but I would want to preserve things like Higurashi and Soma.
So REAL total would still fall below 400 GiB.
(I will add remaining part of post in like 10-15 m because of GOG char and rate limiting)