RetroFedIs EXT4 more efficient then FAT?
cloudskaterJust started dumping data from my individual SSDs onto an old laptop one by one so I can reformat the drives as EXT4 instead of xFAT or FAT32 or whatever I had it as before. I wasn’t aware that EXT4 was better suited for (and exclusive to) Linux until recently, and I’m still new to it. Is it much more efficient on storage space or something?
Like I said, I’ve been copying files to and from an old laptop that holds onto them while I format the drives, but this laptop is old af and takes several hours to copy 1TB, so I often leave it going while I sleep. I woke up this morning to no errors or anything, but the files copied to the drive were ~600gb worth when they were ~800gb before. Surely there isn’t that much of a difference? Any idea what could be causing this?
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Ext4 has better support for various things than FAT filesystems. It can manage longer filenames/paths, supports symlinks, has better privilege controls and so on. It’s not much more efficient, but being a newer system than FAT32 there’s some improvements on that too. So, in general it’s newer tech and thus better than old one, not because it’s built for Linux (or “unix-like” systems).
But for that size difference, unless you had millions (or tens of millions or more) very small files to copy and your block size on FAT32 was somehow funny, I don’t see how that could shrink disk usage by that much. I assume there’s some error on size calculations or something didn’t copy over. Few hundred MBs might be possible, but 200GB is very, very unlikely. Actually I’m not sure if that’s even theoretically possible.
Thanks for the info and yeah that’s what I was thinking, it made no sense. I copied it over again today and the size was identical so I guess something went wrong overnight. Likely sleep mode fucking up the process on an old potato computer. I kept sleep mode suspended during this run and it worked fine. It just took five hours lol
I would first check carefully that all the files were actually copied. Often the simplest explanation is the correct one, in this case that some files weren’t copied for some reason.
That said, I have seen something similar once, and the reason was something called sparse files. We had some database backup files on a FAT32 partition (don’t ask why), and we copied them to an ext4 partition. We noticed that the copied files occupied about 1/4 less space than they did on FAT32. Turned out that the backup files contained large amounts of “empty” space (zeros bacially) and because FAT file systems don’t support sparse files, that empty space occupied physical disk space on FAT32. On ext4 however, those empty parts didn’t consume any physical disk space and thus the total disk usage was way lower.
Does your data include disk images for example? If so, this could be the reason.
You should ensure data integrity with checksums and/or hashes.
Yes. Ext4 is far better (including efficiency) than FAT. A very modern FS versus one of the oldest and terribly inefficient… Lol
FAT typically has large cluster sizes, especially on large volumes. Ext4 has relatively small clusters. A tremendous amount of small files could possibly explain it. Did you happen to enable any compression for the volume?
I did not. Though, I do have the entirety of the Atari 2600 library on that SSD so if you want an example of many small files…
In general EXT4 is better than FAT in terms if its cluster slack (how much space is wasted by minimum cluster size) and it’s also way better at handling problems related to power outages and interruptions than FAT filesystems are.
Its less about efficiency and just about compatibility at least in terms of fat and ext4. Ext4 is open and was designed for Linux, where fat was for windows and was closed off and hard for Linux to support
I’m not sure about the file size diffs, maybe different default compression levels or a incomplete copy?
FAT predates Windows. Lol. I think you might be thinking NTFS? That has been a cluster duck. But FAT was never that difficult to support.
Oh you’re right yeah. I also saw an article also about exfat being opened source by Microsoft in 2019