Linux 6.17 File-System Benchmarks, Including OpenZFS and Bcachefs

Linux 6.17 is an interesting time to carry out fresh file-system benchmarks given that EXT4 has seen some scalability improvements while Bcachefs in the mainline kernel is now in a frozen state. Linux 6.17 is also what's powering Fedora 43 and Ubuntu 25.10 out-of-the-box to make such a comparison even more interesting. Today's article is looking at the out-of-the-box performance of EXT4, Btrfs, F2FS, XFS, Bcachefs and then OpenZFS too.

Due to the mentioned motivating factors, recently I carried out some fresh Linux file-system benchmarks on the Linux 6.17 development kernel. All of the file-systems were tested from a Crucial T705 1TB PCIe Gen5 NVMe SSD (CT1000T705SSD3). Ubuntu 25.10 in its daily form was used for testing with its Linux 6.17.0-4-generic kernel as of testing. As Ubuntu 25.10 also patched an OpenZFS build to work on Linux 6.17, I included that out-of-tree file-system too for this comparison. So tested for this article were:

- Bcachefs
- Btrfs
- EXT4
- F2FS
- OpenZFS
- XFS

Bcachefs was tested in its upstream Linux 6.17 state. Bcachefs is working to roll-out DKMS out-of-tree kernel modules moving forward. The Bcachefs DKMS performance will be evaluated in a separate article when available.

Each file-system was tested with its default mount options and running a range of benchmarks to see how these different Linux file-systems are competing.