I'm curious roughly how much hard drive space you need for all your games. A few TB... more? Did you put them on hard drives, or dvds, or something else?

According to GOG, the size of the entire catalog is about 1.7 TB:
https://twitter.com/GOGcom/status/1579092860477276161
Personally, I have about 450 GBs of games stored, including GOG, Playism, Desura, Humble, GamersGate, and back-up copies of physical games.

It can't be only that little. If they've got 7000 games, then 2000 GB / 7000 games = 0,285 GB. So it's an average of only 285 MB for each game!
This can't be, since (for example) Witcher 3 GOTY is around 20 GB alone, A Plague Tale: Innocence is 36 GB, etc..

353 games with a total of 1240GB (1.24TB).

2TB can't be the whole catalogue, it doesn't say that explicitly either? If so, take that estimate from GOG with a mountain of salt; the total number of entries today is 6941, so, 2TB seem to be way off...

EDIT: Seems gogrepoc didn't download CyberPunk 2077 (probably because I hid it) so the number should be at least 1350+GB.

1.7TiB don't even come close.
I have 1850 games on GOG and I filled close to 7 TiB with offline installers already.
Cyberpunk alone takes 160GB, soe does Shadow of War.

The wrong information maybe has something to do with the wrong information when games are installed. If you look in your list of installed programs, GOG games often show with about 2 MB, even if they take by far more space.

Currently my installed games take about 1.7TiB on my SSD (420 GB for GOG, the rest spread among Uplay, Steam, Origin, Microsoft,Epic,Rockstar,...), older games that don't profit from a SSD very much, I put on a hard drive, they occupy about 1.6TiB. (I should probably uninstall something)


I estimate that for all GOG offline installers would take about 15-20TiB.

I would expect it to be in excess of 8TB if one considers only Windows installers. Mind you I don't even have half of GOG's catalogue, but I am saving Linux installers as well, and am currently up to about 5TB+ used on an 8TB hard drive. Probably a bit overestimated, but not too far off if we get a few more rather recent AAA titles released. That's most likely a statistic for 20th century games or something of the sort, not the entire catalogue.

Hmm, the tweet does mention only 'classics', maybe just the games with the classic tag, or non-indies only.

GOG has about 4220 listed games
https://www.gog.com/en/games?priceRange=0.01,122.39&hideDLCs=true

I excluded free ones and demos, but of course bundles will show up, in total it should be about the same.
So I also have less than half of all the games.
I don't save Linux or mac installers and also removed separated the german installers (I play in english most of the time anyway). Other languages or language packs I don't even download, same goes for separated 32 Bit editions (which are not many). Those remain on GOGs download servers.
I also only keep the newest version (with very very few exceptions). I also din't even download the Mafia 3 Definite Edition, since it's identical to the old edition.

...and that's how I got to 7TB.
With additional languages and versions for different operating systems it would be significantly more.

Now that I think of it: These 7 TB do include goodies except soundtracks, which I keep somewhere else.

It's almost three terabytes (2,89 TB) for a bit more than a thousand games (1096).

But : I keep both the french and the english versions of games (I don't even know why, as french translations and voices in videogames are reliably awful). Plus I'm using gogrepoc, so I have a lot of duplicates (some unwanted languages, some older versions, some 32 bits versions) which I don't clean up anymore because they get re-downloaded anyway. An average would overestimate the space required for clean manual downloads.

And I use external hard drives.

Off topic On a sidenote: You can configure gogrepoc to ignore patches and languages.
It won't avoid duplicates of course.
I have one download dir for gogrepo and a 2nd directory where I keep my downloaders. After downloading the games with an update flag I manually move the downloaded files

This is the script to download a game without extras.
. $(dirname "$0")/gogrepinit.sh //this one loads the environment variables and the content of the ignore list.
echo downloading to "$targetdir"
mkdir -p "$targetdir"
${pythoncommand} ${gogrepodir}/${gogpyname} download "$targetdir" -skipextras -id $1 $skipfilesargument

Part of the init script:
if [ -z "$filterlist" ]; then
echo "$filterlist variable not found"
else
if [ -f "$filterlist" ]; then
filefilter=`cat "$filterlist" | tr '\n\r' ' '`
fi
if [[ ! -z "$filefilter" ]]; then
skipfilesargument="-skipfiles $filefilter"
echo "INFO: 'skipfilesargument' is $skipfilesargument"
fi
fi

Properties file:
pythoncommand=~/venv.gogrepo/bin/python3.9
gogpyname=gogrepoc_2022_09_22.py
gogrepodir=~/gogrepo
targetdir=/......
batchlist=~/gogrepo_batch_ids.txt
filterlist=~/gogrepo/gogrepoignore.txt

filter file:
patch_*.*
*_?32bit?_*.*
*_32_*
*_fr.*
*_Fr.*
*_FR.*
*_ru.*
*_Ru.*
*_RU.*
*_es.*
*_Es.*
*_ES.*

I am a bit of a noob, when it comes to bash scripts, but it does it's job. Only little adjustments are needed after the download

That's interesting. I really haven't started familiarizing myself with this language, so I was simply used the default commands for language. Manually filtering out "32bit" sounds good, but I think some games come only with a 32bit version, which is named as such. So it would just wall off the whole game. I suspect that's why there's no default command for that.

Anyway, off topic yes. But I've pointed out the (or my) "stowaway files" issue in the gogrepo thread itself.

3,37 TB x2, because backup is duplicating and data on servers you don't own is not yours.

I don't keep a separate space on my hard-drive for GOG games. All games I backed up together take up 3,8 TB.

I have everything I want double-backed up onto external HDD's. Optical is more suitable for older games than newer ones (and 23-46GB BD-R more suitable than 4-8GB DVD-R). As for space required, for every 20-60GB Skyrim, Cyberpunk 2077, etc, title, there are often 2-10x much smaller ones (eg, Banished = 122MB, Ben There Dan That = 22MB, Escape Goat = 44MB, Indiana Jones & The Last Crusade = 24MB, To The Moon = 101MB, VVVVVV = 65MB, etc). When you average the whole lot (and particularly if you prefer older to newer games), then the average size per title ends up quite a lot smaller than simply averaging only the largest ones owned. (One common fallacy I've seen is "I haven't bothered to back any of my 1,000x games up because I own a couple of 50GB games and 1,000x of those must be 50TB so I'm not even going to try"). I have a few hundred DOS games (GOG and disk), and realistically they could fit onto a single 23GB BD-R / 32GB USB stick.

You also don't have to back up absolutely everything. If you really didn't like a game then you don't need to back it up. If you don't own a Mac, you don't need the Mac versions. If you prefer an original to a 3x more bloated Remaster, and it still plays fine / has a great source port, there's nothing wrong in keeping it. If you are space limited or find backing up a large collection from scratch too daunting, then even picking your Top 100 favourite games of all time and backing those up (then simply scale that to Top 250 / 500 as space / time permits) is better than nothing or "If I can't back up everything, then I'll do nothing". I have games that I'd be mildly annoyed if I lost, but 95% of favourites I'd miss the most if I lost everything are older (and naturally smaller) titles than any behemoths released in the past few years, typically 0.5-2GB each. You can fit a lot of those onto even a small 4TB 2.5" HDD.

Haven't found such a game so far. Those with only 32 bit don't contain that in their names. Do you have an example?
But still ... those few exceptions could be added manually, it's less work than the other way around.
Yeah, the thread is great, but by now it's way too long. It takes ages to browse through all the pages.
A new one with instructions and a FAQ up front would be best.