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btt

NAME

btt - analyse block i/o traces produces by blktrace

SYNOPSIS

btt [options] -i <input file>
btt -h | --help
btt -V | --version

DESCRIPTION

btt will take in binary dump data from blkparse, and analyse the events, producing a series of output from the analysis. It will also build .dat files containing "range data" -- showing things like Q activity (periods of time while Q events are being produced), C activity (likewise for command completions), and etc.

OPTIONS

-h
--help

Shows a short summary of possible command line option

-V
--version

Shows the version of btt.

-i

Specifies the input file to analyse. This should be a trace file as produces by blktrace (8).

-d <seconds>
--range-delta=<seconds>

The -d option allows you to specify the granularity which determines "activity" with regard to the .dat files -- this specific the time (in seconds) that must elapse without a particular event occurring to signify inactivity. The larger the number, the fewer ranges output -- the default is 0.1 seconds.

-D <dev;...>
--devices=<dev;...>

The -D option supplies the devices which should be looked at when analysing the input. This is a ":" separated list of devices, devices are specified by a mjr,mnr tuple (e.g.: -D "8,0:8,8" specifies two devices with major 8 and minor 0 and 8 respectively).

-e <exe,...>
--exes=<exe,...>

The -e option supplies the list of executables that will have I/Os analysed.

-I <output name>
--iostat=<output name>

The -I option directs btt to output iostat-like data to the specified file. Refer to the iostat (sysstat) documentation for details on the data columns.

-l <output name>
--d2c-latencies=<output name>

The -l option allows one to output per-IO D2C latencies respectively. The supplied argument provides the basis for the output name for each device.

-M <dev map>
--dev-maps=<dev map>

The -M option takes in a file generated by the provided script (gen_disk_info.py), and allows for better output of device names.

-o <output name>
--output-file=<output name>

Specifies the output file name.

-p <output name>
--per-io-dump=<output name>

The -p option will generate a file that contains a list of all IO "sequences" - showing the parts of each IO (Q, A, I/M, D, & C).

-q <output name>
--q2c-latencies=<output name>

The -q option allows one to output per-IO Q2C latencies respectively. The supplied argument provides the basis for the output name for each device.

-s <output name>
--seeks=<output name>

The -s option instructs btt to output seek data, the argument provided is the basis for file names output. There are two files per device, read seeks and write seeks.

-S <interval>
--iostat-interval=<interval>

The -S option specifies the interval to use between data output, it defaults to once per second.

-t <sec>
--time-start=<sec>
-T <sec>
--time-end=<sec>

The -t/-T options allow one to set a start and/or end time for analysing - analysing will only be done for traces after -t's argument and before -T's argument. (-t and -T are optional, so if you specify just -t, analysis will occur for all traces after the time specified. Similarly, if only -T is specified, analysis stops after -T's seconds.)

-v
--verbose

Requests a more verbose output.

AUTHORS

blkparse was written by Jens Axboe, Alan D. Brunelle and Nathan Scott. This man page was created from the blktrace documentation by Bas Zoetekouw.

REPORTING BUGS

Report bugs to <linux-btrace@vger.kernel.org>

COPYRIGHT

Copyright © 2006 Jens Axboe, Alan D. Brunelle and Nathan Scott.
This is free software. You may redistribute copies of it under the terms of the GNU General Public License <http://www.gnu.org/licenses/gpl.html>. There is NO WARRANTY, to the extent permitted by law.
This manual page was created for Debian by Bas Zoetekouw. It was derived from the documentation provided by the authors and it may be used, distributed and modified under the terms of the GNU General Public License, version 2.
On Debian systems, the text of the GNU General Public License can be found in /usr/share/common-licenses/GPL-2.

SEE ALSO

blktrace (8), blkparse (1), verify_blkparse (1), blkrawverify (1), btt (1)