How do I test IO performance in Linux?
IO and filesystem benchmark is a complex topic. No single benchmarking tool is good in all situations. Here is a small overview about different benchmarking tools:
Block Storage:
File System (synthetic):
File System (workload):
Stony Brook University and IBM Watson Labs have published a highly recommended journal paper in the "Transaction of Storage" about file system benchmarking, in which they present different benchmarks and their strong and weak points: A nine year study of file system and storage benchmarking. The article clearly points out that the results of most benchmarks at least questionable.
A note: Is the question programming related? Maybe not, but maybe it is. I spend a lot of time benchmarking the IO performance of the systems I develop. At least for me, questions about how to benchmarking these things is highly programming related. Please: Do not close all questions that are not development/programming related from your point of view. The point of view of other developers might be different.