iowatcher graphs the results of a blktrace run. It can graph the
result of an existing blktrace, start a new blktrace, or start a
new blktrace and a benchmark run. It can then create an image or
movie of the IO from a given trace. iowatcher can produce either
SVG files or movies in mp4 format (with ffmpeg) or ogg format
--help Print a brief usage summary.
-d, --device device
Controls which device you are tracing. You can only trace
one device at a time for now. It is sent directly to
blktrace, and only needed when you are making a new trace.
-D, --blktrace-destination destination
Destination for blktrace.
Run a program while blktrace is run. The program and its
arguments must be specified after all other options. Note
that this option previously required the program to be
given as a single argument but it now tells iowatcher to
expect extra arguments which it should be run during the
-- End option parsing. If --prog is specified, everything
after -- is the program to be run. This can be useful if
the program name could otherwise be mistaken for an
Keep the SVG files generated for movie mode.
-t, --trace path
Specify the name of the file or directory in which
blktrace output is located. iowatcher uses a dump from
blkparse, so this option tries to guess the name of the
corresponding per-CPU blktrace data files if the dump file
doesn't already exist. To add multiple traces to a given
graph, you can specify --trace more than once. If path is
a directory, iowatcher will use the name of the directory
as the base name of the dump file and all trace files
found inside the directory will be processed.
-l, --label label
Sets a label in the graph for a trace file. The labels
are added in the same order as the trace files.
-m, --movie [style]
Create a movie. The file format depends on the extension
used in the -o file option. If you specify an .ogv or
.ogg extension, the result will be Ogg Theora video, if
png2theora is available. If you use an .mp4 extension,
the result will be an mp4 video if ffmpeg is available.
You can use any other extension, but the end result will
be an mp4. The accepted style values are spindle for a
circular disc-like effect (default) or rect for a
rectangular graph style.
-T, --title title
Set a title to be placed at the top of the graph.
-o, --output file
Output filename for the SVG image or video. The video
format used will depend on the file name extension. See
--movie for details.
-r, --rolling seconds
Control the duration for the rolling average. iowatcher
tries to smooth out bumpy graphs by averaging the current
second with seconds from the past. Larger numbers here
give you flatter graphs.
-h, --height height
Set the height of each graph
-w, --width width
Set the width of each graph
-c, --columns columns
Number of columns in graph output
-x, --xzoom min:max
Limit processed time range to min:max.
-y, --yzoom min:max
Limit processed sectors to min:max.
-a, --io-plot-action action
Plot action (one of Q, D, or C) in the IO graph.
Distinguish between processes in the IO graph.
-O, --only-graph graph
Add a single graph to the output (see section GRAPHS for
options). By default all graphs are included. Use -O to
generate only the required graphs. -O may be used more
-N, --no-graph type
Remove a single graph from the output (see section GRAPHS
for options). This option may be used more than once.
Generate graph from the existing trace.dump:
# iowatcher -t trace
Skip the IO graph:
# iowatcher -t trace.dump -o trace.svg -N io
Only graph tput and latency:
# iowatcher -t trace.dump -o trace.svg -O tput -O latency
Generate a graph from two runs, and label them:
# iowatcher -t ext4.dump -t xfs.dump -l Ext4 -l XFS -o
Run a fio benchmark and store the trace in trace.dump, add a
title to the top, use /dev/sda for blktrace:
# iowatcher -d /dev/sda -t trace.dump -T 'Fio Benchmark'
-p fio some_job_file
Make a movie from an existing trace:
# iowatcher -t trace --movie -o trace.mp4
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License v2 as
published by the Free Software Foundation.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
This page is part of the blktrace (Linux block layer I/O tracer)
project. Information about the project can be found at [unknown
-- if you know, please contact firstname.lastname@example.org] It is not
known how to report bugs for this man page; if you know, please
send a mail to email@example.com. This page was obtained from
the project's upstream Git repository
on 2021-08-27. (At that time, the date of the most recent commit
that was found in the repository was 2021-06-28.) If you
discover any rendering problems in this HTML version of the page,
or you believe there is a better or more up-to-date source for
the page, or you have corrections or improvements to the
information in this COLOPHON (which is not part of the original
manual page), send a mail to firstname.lastname@example.org
iowatcher April 2014 iowatcher(1)