The choice of filesystems on Linux is vast, but most people will stick with their respective distributions’ default choices, which will most likely be ext3, but you’re free to use ReiserFS, XFS, or something else completely if you so desire. Things are about to change though, with btrfs just around the corner. To bridge the gap between now and btfrs, ext3 has been updated to ext4, which adds some interesting features like extents, which are already in use in most other popular file systems. Phoronix decided it was time to do some performance checking on ext4.
After testing, Phoronix concludes that ext4 isn’t an enormous leap forward compared to other file systems, but that it did show a performance advantage over ext3 in pure disk benchmarks – but as they state, that only helps if your job is to run disk benchmarks day-in, day-out (quote of the day, I must say). However, that is not to say that ext4 isn’t worthwhile – there are more important things than raw performance when it comes to file systems.
EXT4 is clearly a significant improvement over EXT3 when it came to the pure disk benchmarks, however, in the real world, saying better performance should not be used as a reason to replace your existing EXT3 or XFS partitions. In our tests that cater towards Linux desktop users and gamers, EXT4 hadn’t delivered a sizable quantitative advantage. That’s not to say though it’s not worth switching to EXT4. EXT4 is more scalable, more efficient through the use of Extents, supports larger disk capacities, can handle twice the number of sub-directories, is capable of handling online defragmentation, and there is improved reliability via journal checksums. What perhaps is more important is that with the addition of these new features, the performance hasn’t regressed. Also, when testing the EXT4 file-system, we hadn’t run into any problems with stability, file corruption, or any other issues.
Ext4 has been available as an option on Fedora for a while now (append the
ext4 boot parameter when booting Anaconda), but for the rest, no major distributions are shipping it yet. It will become part of the next Linux kernel release, so we may see an increase soon enough. Mostly, however, as Phoronix notes, adoption of ext4 will depend on how fast btrfs becomes stable and well-tested.