Blktrace is a block layer IO tracing mechanism which provides detailed information about request queue operations up to user space. There are three major components that are provided:

blktrace: A utility which transfers event traces from the kernel into either long-term on-disk storage, or provides direct formatted output (via blkparse).

blkparse: A utility which formats events stored in files, or when run in live mode directly outputs data collected by blktrace.

iowatcher: A utility to visualize block I/O patterns. It generates graphs from blktrace runs to help visualize IO patterns and performance. It can plot multiple blktrace runs together, making it easy to compare the differences between different benchmark runs.