Hello everyone, The defrag code in v0.6 seems to have been really good at triggering a bug in my extent tree allocation code. So, I've put out v0.7 with the fix. There are also a bunch of defrag refinements and Josef's fsync improvments included. To give you an idea of how much the defrag code and related readahead fixes help: Time to create 1 million files, 512 bytes each: v0.4: 3m17s v0.7: 2m32s Time to run find . on the directory: v0.4: 21.60s v0.7: 3.27s Unfortunately the time to read all the files with tar isn't much better because Btrfs is still seeking around the directory name index. I need to figure out a better way to get around that. -chris