*Edit: I have figured out how to use BTRFS and enable what it calls “transparent file compression”, and I’m going to use that on most of my old storage devices. The only problem I’m having is that I want to use F2FS on my oldest storage device, as BTRFS takes up too much space on the device and I was told by multiple users that F2FS also supports transparent file compression, but I can’t get files to compress and I’m not getting any error messages to try and fix it. Based on what the documentation says, I’m supposed to do something like this:
sudo mkfs.f2fs -f -O extra_attr,inode_checksum,sb_checksum,compression /dev/mmcblk0p1
sudo mount -o compress_algorithm=zstd,compress_extension=* /dev/mmcblk0p1 '/home/j/mountpoint/128mb'
chattr -R +c '/home/j/mountpoint/128mb'
The device will mount like this but files aren’t compressing when added, nor are they compressed if using the last command after they’ve been moved.*
I’m rewriting the old portion for clarification:
In Windows, there’s a file/folder option called “Compress contents to save disk space”. What it does is it compresses the files, as the name suggests, but leaves them accessible as though they aren’t. This doesn’t really have much of a benefit on newer storage devices but on older storage devices, in addition to saving space, it allows files to potentially read faster.
As I have some old storage devices that I want to run games from, I think this will be a great option to have if I could find something similar for Linux. I tried looking online myself but search engines are terrible and I couldn’t find anything though them. So, I decided to post about this here, to see if anyone knows of anything I could try.
It is an sd card and I did just format it to f2fs but how do I enable the compression? It does seem much faster that ext4 but it seems to also take up more space on the sd card, as I’ve lost about 25% of the free space after formatting it, so I’d like to enable the compression.
As for zfs, I have been using Linux for over a few years at this point but I’ve mostly been avoiding some of the more complicated stuff. So if it is more complicated than what I originally thought, then I’ll avoid that for now as well.
So, first of all, there is no gui for this, that I’m aware of, so you will have to do it from terminal. Second, on f2fs, compression works that you don’t enable compression for a folder, instead you mount the drive with compression enabled, and new files will be compressed automatically.
So what you need is to set up your disk to be mounted with compression. There are many paths you can follow here. If you want your drive to be (almost) permanently connected, the easiest way is to use “/etc/fstab”. If you want to use it as a regular SD card, mounting and ejecting it from your file explorer etcetera, then you should go here and learn how to have udisks2 mount your device with compression, which should be what your desktop environment uses to mount drives. I suggest you set that up for your specific device, and not for all f2fs devices. Good luck.
You can look up other useful f2fs options on the arch wiki. I suggest you add all those options that reduces writes to your disk and improve durability (like lazytime).
You should use zstd as compression algorithm, and because this is a slow and small drive, you can crank up the level of compression.
If you manage to pull this off, the next time you install a (bigger and faster) drive on your pc, you can try to look into zfs.
I read the page you linked to but I have no idea what I’m supposed to do with it. If it’s talking about using the “mount” command, I’ve already used that and even though I specifically enabled zstd as the compression method, files aren’t being compressed. I know this because I’m using a file that’s slightly larger than the free space but it’s still giving errors about not having enough space.
That is not a good method for testing. Maybe the filesystem still requires new files to be smaller than free space. Or maybe the file could be not really compressible, for example, you won’t be able to compress random data. You also won’t compress already compressed data, like videos.
You could write a real text file of some kB and then check the compression ratio with something like “compsize”.
The mount command mounts the disk with the options you give to it but only once. Now, because you don’t want to manually run mount everytime you use your disk, you must set it up so it is always mounted with the options you want. Udisks2 is one of the tools for that.
edit: apparently compsize is btrfs only. You can use “du” with and without --apparent-size and check the differenze
I used a folder full of smaller files and it still isn’t compressing them. I’ve tried everything I can find or was told to do with f2fs but I cannot for the life of me, get files to compress. Btrfs works and files are compressing but it takes up so much space on the sd card.
I have a similar setup and it works. So you are probably doing something wrong, I don’t know what. Maybe look at dmesg for a filesystem error.
I checked dmesg and there’s no errors. As I said in my post, I’m not getting any error messages, so I have nothing to diagnose the problem with.