--- name: "pt-ioprofile" section: "1p" platform: "linux" package: "percona-toolkit" version: "3.7.1_4-1" release: "Arch Linux 2026-11-01" platforms: ["linux"] url: "https://new.carta.tech/pt-ioprofile" --- # pt-ioprofile(1p) Watch process IO and print a table of file and I/O activity. ## NAME pt-ioprofile - Watch process IO and print a table of file and I/O activity. ## SYNOPSIS Usage: pt-ioprofile \[OPTIONS\] \[FILE\] pt-ioprofile does two things: 1) get lsof+strace for -s seconds, 2) aggregate the result. If you specify a FILE, then step 1) is not performed. ## RISKS **WARNING**: pt-ioprofile freezes the server and may crash the process, or make it perform badly after detaching, or leave it in a sleeping state! Before using this tool, please: - • Read the tool's documentation - • Review the tool's known "BUGS" - • Test the tool on a non-production server - • Backup your production server and verify the backups pt-ioprofile should be considered an intrusive tool, and should not be used on production servers unless you understand and accept the risks. ## DESCRIPTION pt-ioprofile uses `"strace"` and `"lsof"` to watch a process's IO and print out a table of files and I/O activity. By default, it watches the mysqld process for 30 seconds. The output is like: ``` Tue Dec 27 15:33:57 PST 2011 Tracing process ID 1833 total read write lseek ftruncate filename 0.000150 0.000029 0.000068 0.000038 0.000015 /tmp/ibBE5opS ``` You probably need to run this tool as root. pt-ioprofile works by attaching `"strace"` to the process using `ptrace()`, which will make it run very slowly until `"strace"` detaches. In addition to freezing the server, there is some risk of the process crashing or performing badly after `"strace"` detaches from it, or of `"strace"` not detaching cleanly and leaving the process in a sleeping state. As a result, this should be considered an intrusive tool, and should not be used on production servers unless you are comfortable with that. ## OPTIONS - \--aggregate short form: -a; type: string; default: sum The aggregate function, either `"sum"` or `"avg"`. If sum, then each cell will contain the sum of the values in it. If avg, then each cell will contain the average of the values in it. - \--cell short form: -c; type: string; default: times The cell contents. Valid values are: ``` VALUE CELLS CONTAIN ===== ======================= count Count of I/O operations sizes Sizes of I/O operations times I/O operation timing ``` - \--group-by short form: -g; type: string; default: filename The group-by item. Valid values are: ``` VALUE GROUPING ===== ====================================== all Summarize into a single line of output filename One line of output per filename pid One line of output per process ID ``` - \--help Print help and exit. - \--profile-pid short form: -p; type: int The PID to profile, overrides "--profile-process". - \--profile-process short form: -b; type: string; default: mysqld The process name to profile. - \--run-time type: int; default: 30 How long to profile. - \--save-samples type: string Filename to save samples in; these can be used for later analysis. - \--version Print the tool's version and exit. ## ENVIRONMENT This tool does not use any environment variables. ## SYSTEM REQUIREMENTS This tool requires the Bourne shell (*/bin/sh*). ## BUGS For a list of known bugs, see \. Please report bugs at \. Include the following information in your bug report: - • Complete command-line used to run the tool - • Tool "--version" - • MySQL version of all servers involved - • Output from the tool including STDERR - • Input files (log/dump/config files, etc.) If possible, include debugging output by running the tool with `"PTDEBUG"`; see "ENVIRONMENT". ## ATTENTION Using \ might expose passwords. When debug is enabled, all command line parameters are shown in the output. ## DOWNLOADING Visit \ to download the latest release of Percona Toolkit. Or, get the latest release from the command line: ``` wget percona.com/get/percona-toolkit.tar.gz wget percona.com/get/percona-toolkit.rpm wget percona.com/get/percona-toolkit.deb ``` You can also get individual tools from the latest release: ``` wget percona.com/get/TOOL ``` Replace `"TOOL"` with the name of any tool. ## AUTHORS Baron Schwartz ## ABOUT PERCONA TOOLKIT This tool is part of Percona Toolkit, a collection of advanced command-line tools for MySQL developed by Percona. Percona Toolkit was forked from two projects in June, 2011: Maatkit and Aspersa. Those projects were created by Baron Schwartz and primarily developed by him and Daniel Nichter. Visit \ to learn about other free, open-source software from Percona. ## COPYRIGHT, LICENSE, AND WARRANTY This program is copyright 2011-2026 Percona LLC and/or its affiliates, 2010-2011 Baron Schwartz. THIS PROGRAM IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2; OR the Perl Artistic License. On UNIX and similar systems, you can issue \`man perlgpl' or \`man perlartistic' to read these licenses. You should have received a copy of the GNU General Public License, version 2 along with this program; if not, see \. ## VERSION pt-ioprofile 3.7.1-4