I've made the observation that FSFS repositories perform better on EXT4 than BTRFS. This probably isn't ground-breaking, but I thought I'd share it.
I've got two Linux machines: - colossus, using BTRFS spanned over two disks. 2.6.38-11-generic #48-Ubuntu SMP Fri Jul 29 19:02:55 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux - oberon, using EXT4 on a 2-disk software RAID-1 set. Linux oberon 2.6.32-33-generic #72-Ubuntu SMP Fri Jul 29 21:07:13 UTC 2011 x86_64 GNU/Linux I've noticed that writes to FSFS repositories are 5x faster under EXT4 than BTRFS. When svnsyncing form the same svn:// source to an local repository (file://), oberon completes about 400 revisions in the time it takes colossus to grind through 80. The BTRFS machine is our build server. Performance with (1.6.x) working copies is quite acceptable, but I'm glad I'm not using it to host svn repositories. Looks like the BTRFS people have some work to do. Maybe current Kernels have already improved this picture. I know there has been recent work on reducing the cost of meta-data operations (e.g. file creation, ...) and that work is ongoing on defragmentation functionality because of poor performance on files that are modified in place heavily (e.g. sqlite). // ben
