doc/iowatcher.1

.TH iowatcher "1" "April 2014" "iowatcher" "User Commands"

.SH NAME
iowatcher - Create visualizations from blktrace results

.SH SYNOPSIS
.B iowatcher
\fI[options]\fR [--] \fI[program arguments ...]\fR

.SH DESCRIPTION
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 (with png2theora).

.SH OPTIONS
.TP
\fB--help\fP
Print a brief usage summary.
.TP
\fB-d, --device\fP \fIdevice\fP
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.
.TP
\fB-D, --blktrace-destination\fP \fIdestination\fP
Destination for blktrace.
.TP
\fB-p, --prog\fP
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 \fBiowatcher\fP
to expect extra arguments which it should be run during the trace.
.TP
\fB--\fP
End option parsing. If \fB--prog\fP is specified, everything after \fB--\fP is
the program to be run. This can be useful if the program name could otherwise
be mistaken for an option.
.TP
\fB-K, --keep-movie-svgs\fP
Keep the SVG files generated for movie mode.
.TP
\fB-t, --trace\fP \fIpath\fP
Specify the name of the file or directory in which blktrace output is located.
\fBiowatcher\fP 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
\fB--trace\fP more than once.  If \fIpath\fP is a directory, \fBiowatcher\fP
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.
.TP
\fB-l, --label\fP \fIlabel\fP
Sets a label in the graph for a trace file.  The labels are added in the same order as the trace files.
.TP
\fB-m, --movie\fP \fI[style]\fP
Create a movie.  The file format depends on the extension used in the \fB-o\fP
\fIfile\fP 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 \fIstyle\fP values
are \fBspindle\fP for a circular disc-like effect (default) or \fBrect\fP for a
rectangular graph style.
.TP
\fB-T, --title\fP \fItitle\fP
Set a \fItitle\fP to be placed at the top of the graph.
.TP
\fB-o, --output\fP \fIfile\fP
Output filename for the SVG image or video. The video format used will depend
on the file name extension. See \fB--movie\fP for details.
.TP
\fB-r, --rolling\fP \fIseconds\fP
Control the duration for the rolling average.  \fBiowatcher\fP tries to smooth out bumpy graphs by averaging the current second with seconds from the past.  Larger numbers here give you flatter graphs.
.TP
\fB-h, --height\fP \fIheight\fP
Set the height of each graph
.TP
\fB-w, --width\fP \fIwidth\fP
Set the width of each graph
.TP
\fB-c, --columns\fP \fIcolumns\fP
Number of columns in graph output
.TP
\fB-x, --xzoom\fP \fImin:max\fP
Limit processed time range to \fImin:max\fP.
.TP
\fB-y, --yzoom\fP \fImin:max\fP
Limit processed sectors to \fImin:max\fP.
.TP
\fB-a, --io-plot-action\fP \fIaction\fP
Plot \fIaction\fP (one of Q, D, or C) in the IO graph.
.TP
\fB-P, --per-process-io\fP
Distinguish between processes in the IO graph.
.TP
\fB-O, --only-graph\fP \fIgraph\fP
Add a single graph to the output (see section \fBGRAPHS\fP for options).  By
default all graphs are included. Use \fB-O\fP to generate only the required
graphs.  \fB-O\fP may be used more than once.
.TP
\fB-N, --no-graph\fP \fItype\fP
Remove a single graph from the output (see section \fBGRAPHS\fP for options).
This option may be used more than once.
.SH GRAPHS
Values accepted by the \fB-O\fP and \fB-N\fP options are:

   io, tput, latency, queue_depth, iops, cpu-sys, cpu-io, cpu-irq, cpu-user, cpu-soft

.SH EXAMPLES
Generate graph from the existing trace.dump:
.PP
.RS
# iowatcher -t trace
.RE
.PP
Skip the IO graph:
.PP
.RS
# iowatcher -t trace.dump -o trace.svg -N io
.RE
.PP
Only graph tput and latency:
.PP
.RS
# iowatcher -t trace.dump -o trace.svg -O tput -O latency
.RE
.PP
Generate a graph from two runs, and label them:
.PP
.RS
# iowatcher -t ext4.dump -t xfs.dump -l Ext4 -l XFS -o trace.svg
.RE
.PP
Run a fio benchmark and store the trace in trace.dump, add a title to the top, use /dev/sda for blktrace:
.PP
.RS
# iowatcher -d /dev/sda -t trace.dump -T 'Fio Benchmark' -p fio some_job_file
.RE
.PP
Make a movie from an existing trace:
.PP
.RS
# iowatcher -t trace --movie -o trace.mp4
.RE

.SH AUTHORS
iowatcher was created and is maintained by Chris Mason.

This man page was largely written by Andrew Price based on Chris's original README.

.SH COPYRIGHT
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 02110-1301 USA

.SH "SEE ALSO"
.BR blktrace (8),
.BR blkparse (1),
.BR fio (1),
.BR mpstat (1)