Current:
In fact, users will have even more space because of Btrfs’ use of transparent compression. Compressing data reduces total writes, saving space and improving flash drive life. In many cases, it can also improve performance. Compression can be enabled on an entire file system, or per subvolume, directory, and even per file. Btrfs also uses a “copy on write” model: when copying a file, it does not write new data until you actually change the old data, saving even more space.
Rewrite:
Btrfs uses a “copy-on-write” model: your data and the file system itself are never overwritten. This enhances crash-safeness. When copying a file, Btrfs does not write new data until you actually change the old data, saving space.
In fact, users will save more space when using Btrfs’ transparent compression. Compressing data reduces total writes, saves space, and extends flash drive life. In many cases, it can also improve performance. Compression can be enabled on an entire file system, or per subvolume, directory, and even per file. You will be able to opt-in to using compression in Fedora 33. And it’s one of the features we’re looking forward to taking advantage of by default in future Fedora releases.
[The “saves space” in the rewrite is something I’m on the fence about. I’m inclined to strike it because it’s becoming redundant, but might add a bit of clarity that this form of space savings is different than the “efficient copy” space savings mentioned in the previous paragraph. I leave it up to editors to keep it in or toss it.]
