Capturing and analyzing I/O data

A short overview of how to capture and to analyze the I/O trace data.

About this task

Capturing and analyzing the I/O data involves different tools:

blktrace
captures the data from the running kernel, optionally sends it over the network to minimize the impact on the running system and stores the data in a binary format.
blkparse
parses the data captured by blktrace, displays it in a readable format, adds a summary and creates data usable by btt.
btt
does further analysis and can create histogram data for plotting with Grace4 or other plotting tools.

See the blktrace documentation for more examples of what data is available.