Git repo

• https://github.com/axboe/fio

References to get started!

• Fio Documentation
• https://www.linux.com/training-tutorials/inspecting-disk-io-performance-fio/
• https://arstechnica.com/gadgets/2020/02/how-fast-are-your-disks-find-out-the-open-source-way-with-fio/

Tutorials!

• Fio Operation, size
• Fio block size
• Fio I/O engine
• Fio fork n jobs
• Fio n threads job (instead of fork)
• Fio custom job name

Few Points!

• In below image, fio is running 2 threads and both threads are performing randread operations on same file. Surprisingly latency values (highlighted in red) are quite different. For one thread, time taken to complete one i/o operation is about 126 on avg and for another thread, time taken is around 126000. What are we missing? Why such drastic difference in values?
  
  
  We are missing the units of values. Observe, for thread 1 units are microseconds and for 2nd thread, units are nanoseconds. Hence, both values are approximately equal.