" Is this due to ext3's relaxed notion of fsync?" -- I believe so, especially given the warning about ext4 at the bottom. >The preceding numbers are for an ext

" Is this due to ext3's relaxed notion of fsync?" -- I believe so, especially given the warning about ext4 at the bottom. >The preceding numbers are for an ext3 file system. Synchronous writes are much slower under ext4 (LevelDB drops to ~34 writes / second, TreeDB drops to ~5 writes / second; SQLite3 drops to ~24 writes / second) due to ext4's different handling of fsync / msync calls. Even LevelDB's asynchronous write performance drops somewhat since it spreads its storage across multiple files and issues fsync calls when switching to a new file.