Btrfs v0.19 Brings Some Gains, Some Losses
When starting by compressing a 2GB file using Parallel BZIP2, the results under the Linux 2.6.31-rc2 kernel with Btrfs v0.19 were actually worse than when using the latest stable kernel with Btrfs v0.18. Btrfs v0.19 was about 15% slower. However, due to the different kernels, it could be directly related to either the Btrfs file-system changes or something else to do with the disk sub-system, as we noted in our early Linux 2.6.31 kernel benchmarks there have been a few sore spots.
Running Bork File Encrypter was also noticeably slower when running the latest Linux code. The difference here was 67 seconds versus 78 seconds, which is about a 16% difference.
When moving to IOzone for our disk tests, a speed boost was proven. When measuring the 2GB write performance, under the old Btrfs and kernel the average speed ended up being 43MB/s, but under Btrfs v0.19 and the newer kernel it was at 50MB/s.