PDXPUG – February Meeting 2/19/2009 – Using iostat and blktrace to analyze i/o performance

Ed Borasky will be speaking at the next PDXPUG meeting at FreeGeek (at 7:00pm – 1731 SE 10th Avenue, Portland, OR).

Common wisdom is that “PostgreSQL applications are I/O bound.” Fortunately, Linux has two tools that make analysis of I/O performance metrics possible: “iostat” and “blktrace”. “iostat” gives device-level operational queuing metrics, and in kernels since 2.6.25, queuing metrics for individual partitions as well. “blktrace” provides a detailed trace of every major event in the life of every I/O operation at the block layer.

This talk looks at some recent “iostat” and “blktrace” results from a single-disk workstation running “pgbench”. I’ll include a brief overview of the operational queuing metrics that “iostat” gives, a brief run-down on how to install and run “blktrace”, and some sample “blktrace” output.

Looking forward to seeing everyone there….and of course, drinks at the Lucky Lab (http://www.luckylab.com/ ) at 915 SE Hawthorne Blvd. afterwards.