Bonnie++ vs Iometer

Bonnie++ is a free, command-line benchmark suite for measuring filesystem and disk I/O performance on Linux. It exercises sequential input and output, rewrites, random seeks, and file operations including creation, stat, and deletion of many small files. The project describes these workloads as useful for investigating I/O bottlenecks in I/O-intensive applications, including database work, and for simulating file activity associated with Squid or INN. Bonnie++ can test more than 2 GB of storage on a 32-bit machine. Its -D option enables direct I/O for bulk tests, while -b calls fsync after each write and syncs the directory after file creation or deletion. Semaphore support can synchronize multiple instances. Results can be emitted as plain text or CSV, with companion tools to convert CSV into HTML or formatted plain text. The project is licensed under GPL version 2.0, and the repository includes source code and Debian, RPM, and Sun-related packaging files. Its documentation warns against running the benchmark on live production machines because it can affect services and consume disk space or inodes.

Iometer has no write-up on Specifiction yet; its figures are above.