Provided by: blktrace_1.2.0-2_amd64 bug

NAME

       btt - analyse block i/o traces produces by blktrace

SYNOPSIS

       btt
       [ -a               | --seek-absolute ]
       [ -A               | --all-data ]
       [ -B <output name> | --dump-blocknos=<output name> ]
       [ -d <seconds>     | --range-delta=<seconds> ]
       [ -D <dev;...>     | --devices=<dev;...> ]
       [ -e <exe,...>     | --exes=<exe,...>  ]
       [ -h               | --help ]
       [ -i <input name>  | --input-file=<input name> ]
       [ -I <output name> | --iostat=<output name> ]
       [ -l <output name> | --d2c-latencies=<output name> ]
       [ -L <freq>        | --periodic-latencies=<freq> ]
       [ -m <output name> | --seeks-per-second=<output name> ]
       [ -M <dev map>     | --dev-maps=<dev map>
       [ -o <output name> | --output-file=<output name> ]
       [ -p <output name> | --per-io-dump=<output name> ]
       [ -P <output name> | --per-io-trees=<output name> ]
       [ -q <output name> | --q2c-latencies=<output name> ]
       [ -Q <output name> | --active-queue-depth=<output name> ]
       [ -r               | --no-remaps ]
       [ -s <output name> | --seeks=<output name> ]
       [ -S <interval>    | --iostat-interval=<interval> ]
       [ -t <sec>         | --time-start=<sec> ]
       [ -T <sec>         | --time-end=<sec> ]
       [ -u <output name> | --unplug-hist=<output name> ]
       [ -v               | --verbose ]
       [ -V               | --version ]
       [ -X               | --easy-parse-avgs ]
       [ -z <output name> | --q2d-latencies=<output name> ]
       [ -Z               | --do-active ]

DESCRIPTION

       btt  is a post-processing tool for the block layer IO tracing tool called blktrace(8).  As
       noted in its documentation, blktrace is a block layer IO tracing mechanism which  provides
       detailed information about request queue operations up to user space.

       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.

       Included with the distribution is a simple 3D plotting utility, bno_plot, which  can  plot
       the block numbers btt outputs if the -B option is specified. The display will display each
       IO generated, with the time (seconds) along the X-axis, the block number (start) along the
       Y-axis and the number of blocks transferred in the IO represented along the Z-axis.

OPTIONS

       -a
       --seek-absolute
           When specified on the command line, this directs btt to calculate seek distances based
           solely upon the ending block address of one IO, and the start of the next.  By default
           btt  uses  the concept of the closeness to either the beginning or end of the previous
           IO. See the Users Manual for more details about seek distances.

       -A
       --all-data
           Normally btt will not print out verbose information concerning  per-process  and  per-
           device data.  If you desire that level of detail you can specify this option.

       -B <output name>
       --dump-blocknos=<output name>
           This  option  will  output  absolute  block  numbers  to  three  files prefixed by the
           specified output name:

           prefix_device_r.dat
                  All read block numbers are output, first column is time  (seconds),  second  is
                  the block number, and the third column is the ending block number.

           prefix_device_w.dat
                  All  write  block numbers are output, first column is time (seconds), second is
                  the block number, and the third column is the ending block number.

           prefix_device_c.dat
                  All block numbers (read and write) are output, first column is time  (seconds),
                  second is the block number, and the third column is the ending block number.

       -d <seconds>
       --range-delta=<seconds>
           btt  outputs  a  file  containing Q and C activity, the notion of active traces simply
           means that there are Q or C traces occurring within a certain period  of  each  other.
           The  default  values  is  0.1  seconds;  with  this option allowing one to change that
           granularity. The smaller the value, the more data points provided.

       -D <dev;...>
       --devices=<dev;...>
           Normally, btt will produce data for all devices detected in the  traces  parsed.  With
           this option, one can reduce the analysis to one or more devices provided in the string
           passed to this option. The device identifiers are the major and minor number  of  each
           device,  and each device identifier is separated by a colon (:). A valid specifier for
           devices 8,0 and 8,8 would then be: 8,0:8,8.

       -e <exe,...>
       --exes=<exe,...>
           The -e option supplies the list of executables that will have I/Os analysed.

       -h
       --help
           Shows a short summary of possible command line option

       -i <input name>
       --input-file <input file>
           Specifies the input file to analyse.  This should be a trace file produced by blktrace
           (8).

       -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.

       -L <freq>
       --periodic-latencies=<freq>
           The  -L  option allows one to output periodic latency information for both Q2C and D2C
           latencies. The frequency specified will regulate  how  often  an  average  latency  is
           output -- a floating point value expressing seconds.

       -m <output name>
       --seeks-per-second=<output name>
           Trigger  btt  to  output seeks-per-second information. The first column will contain a
           time value (seconds), and the second column  will indicate the  number  of  seeks  per
           second at that point.

       -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).

       -P <output name>
       --per-io-trees=<output name>
           The  -P  option  will  generate  a  file  that contains a list of all IO "sequences" -
           showing only the Q, D & C operation times. The D & C time values  are  separated  from
           the Q time values with a vertical bar.

       -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.

       -Q <output name>
       --active-queue-depth=<output name>
           The -Q option allows one to output data files showing the time stamp and the depth  of
           active commands (those issued but not completed).

       -r
       --no-remaps
           Ignore remap traces; older kernels did not implement the full remap PDU.

       -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.)

       -u <output name>
       --unplug-hist=<output name>
           This option instructs btt to generate a data file containing histogram information for
           unplug traces on a per device basis. It shows how many times an unplug was hit with  a
           specified  number  of  IOs  released.  There  are  21  output values into the file, as
           follows:

               a value of 0 represents 0..4 counts
               a value of 1 represents 5..9 counts
               a value of 2 represents 10..14 counts
               etc, until
               a value of 20 represents 100+ counts

           The file name(s) generated use the text string passed as an argument for  the  prefix,
           followed  by  the  device  identifier in major,minor form, with a .dat extension.  For
           example, with -u up_hist specified on the command line: up_hist_008,032.dat.

       -V
       --version
           Shows the version of btt.

       -v
       --verbose
           Requests a more verbose output.

       -X
       --easy-parse-avgs
           Provide data in an easy-to-parse form and write it to a file with .avg exentsion

       -z <output name>
       --q2d-latencies=<output name>
           The -z option allows one to output per-IO Q2D  latencies  respectively.  The  supplied
           argument provides the basis for the output name for each device.

       -Z
       --do-active
           The  -Z will output files containing data which can be plotted showing per-device (and
           total system) I/O activity.

AUTHORS

       btt was written by Alan D.  Brunelle.   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

       The btt Users Guide, which can be found in /usr/share/doc/blktrace/btt.pdf
       bno_plot (1), blktrace (8), blkparse (1), verify_blkparse (1), blkrawverify (1), btt (1)