Btrfs Battles EXT4 With The Linux 2.6.33 Kernel

Earlier this week we published extensive benchmarks of EXT4 that looked at the performance of this Linux file-system under every major kernel release since it was declared stable in the Linux 2.6.28 release. EXT4 has encountered many significant performance losses over time as its developers batten up the data security, but there have been some improvements too. At the same time though the developers working on the still-experimental Btrfs file-system continue to move along and push forward changes with each kernel cycle. Just last month we delivered Btrfs comparative benchmarks using the Linux 2.6.32 kernel, but already out of our own personal interest and requests from readers, we have new tests atop the latest Linux 2.6.33 kernel.

Our 2.6.32 file-system benchmarks compared the performance directly of EXT3, EXT4, XFS, ReiserFS, and Btrfs. These results remain relevant so check them out if you are interested in the performance of these other Linux file-systems. For this article we are simply comparing the performance of the EXT4 and Btrfs file-systems using the Linux 2.6.33-rc4 kernel.

The test system is the same ASRock ION 330HT-BD NetTop that we used earlier this week with a dual-core Intel Atom 330 with Hyper Threading, ASRock AMCP7AION-HT motherboard with NVIDIA's MCP79 Chipset, 2GB of system memory, a 320GB Seagate ST9320325AS hard drive, and NVIDIA ION (GeForce 9400M) graphics. Ubuntu 9.04 x86_64 was the distribution running with X Server 1.6.0, xf86-video-nv driver, GCC 4.3.3, and the Linux 2.6.33-rc4 kernel from Ubuntu's mainline kernel PPA.

As we delivered the results earlier this week from EXT4 with its default mount options and then with the no barrier mount option added in, which is designed to improve the performance in some scenarios, we tested Btrfs in two different scenarios. The first Btrfs testing was with all of the stock mount options and then the second run was when Btrfs was mounted with the compress option. Since last year the Btrfs file-system has supported transparent compression of file data using zlib, which of course will result in saved disk space and also better performance, albeit with some overhead that we will talk about later.

The same benchmarks were ran from the EXT4 article earlier this week with the exception of AIO-Stress, which would fail immediately when run on the Btrfs file-system. The other tests through the Phoronix Test Suite included Dbench, FS-Mark, IOzone, Threaded I/O Tester, PostgreSQL, and PostMark.

On the following pages are our very latest test results from the Linux 2.6.33 kernel and the very popular EXT4 and Btrfs file-systems.