For 3DS games I use NDSTokyoTrim to remove useless data from the game files to make them smaller.
DreamCast, PS1 & PS2 games get compressed to chd with chdman.
GameCube and Wii are compressed to rvz with Dolphin.
PS3 I remove the PS3_UPDATE folder, 256MiB for each game adds up. I also use Gnarly Repacks for PS3 games since they have better compression than anything I've tried so far.
Switch games, I use nsz.
Then I use tar with zst on all of them, Nsz and rvz already use zst so theres no change but I just like to keep everything the same accross all of my roms and pc games.
Everything else, GB, NDS, SNES etc all get archived and compressed with tar and zst. For these I'll also use the --ultra -22 option since they're small enough files anyway so they don't take long to compress/decompress. If anyone knows any specific compression/trimming methods that are better than zst, I'd love to hear about them!
Copies of all the tar archives are kept on 2 separate drives and a copy of the games are on my PC in whatever the smallest format is that is compatible with their emulator.
--ultra it should be redundant but for some reason its needed for higher levels of compression.
-22 the highest level of compression offered by zstd.
-c for compress.
-v for verbose.
-f for the file name.
-C excludes the absolute path to the file/directory and just takes YourFile as the file/directory to compress. Its not needed if you're in the same directory as YourFile.
I would recommend leaving out
--ultra -22
and just test how much compression you get with the default level first because 22 is super slow and if it just can't compress the file you won't see any difference in file size compared to the default compression level.
Whatever file format I use them in is also how I back them up, I backup my entire desktop's and laptop's data to an external hard drive and an online service provider. I'm sure a compressed format would be more space efficient but that would take much more time given my use case.
In the case of my laptop it runs Linux and the filesystem I use supports "transparent compression" (almost all contents of the drive are compressed with zstd), so I'm guessing any of the ROMs on there will have already been compressed as nuch as they can (but I'm not knowledgeable enough on the file format specs)
Your backup is probably already compressed. Why do both, have the risk of corruption and being un-unpackable, work of doing it vs just hsving ine backup and be done.
Only upside would maybe be local space storage
@LordPassionFruit wouldn't it be easier to go with something like ./[game]/[platform]/ and then in the platform folder to add all the game specific files for each platform?
Some older consoles have very negligible size libraries in modern day terms, and who knows what sources of ROMs will be taken down by lawsuits in the next few decades. I feel like there is some sense in making a complete archive of a systems game library, but for my personal use I usually just download / dump / rip what I need specifically.
If anybody has a good option let me know. I tried using one drive to back up my entire lunchbox install (about 780GB) and Microsoft said nope. Apparently they give you 1 TB of storage but if you upload too much they cut you off. Pretty lame.
@Outtatime probably they have an upload quota per each week/month. Just wait for a while and see if you still have the issue. Or just archive the full thing.
I Normally just leave them as they are when i downloaded them and chuck them in a folder on my server which I can pull down on any device when I need them.
If the emulator can't run games from archive files, then I store what I play unarchived, and what I don't play stays as archived as it was.
Unless they're small files, then I'd probably back then up extracted. But I haven't had a case where the files were small enough for me to store extracted but the emulator couldn't run from archives.