Ok, to follow up on this topic, I cannot reproduce the fragmentation rate you are observing. My tests from another thread only result in fragmentation of /dev/sda1: 952521/1908736 files (0.3% non-contiguous), e4defrag -c also returns a score of zero—best possible. I will have yet to test du -s though after an explicit fsck -D—adding it to my test runner now. After all, synthetic scores don’t always reflect reality.