blkiomon(8) — Linux manual page


BLKIOMON(8)                                                  BLKIOMON(8)

NAME         top

       blkiomon - monitor block device I/O based o blktrace data

SYNOPSIS         top

       blkiomon -I interval [ -h file ] [ -b file ] [ -d file ] [ -D
       file ] [ -Q path_name -q msg_queue_id -m msg_id ] [ -V ]

DESCRIPTION         top

       blkiomon is a block device I/O monitor. It periodically generates
       per-device request size and request latency statistics from
       blktrace data. It provides histograms as well as data that can be
       used to calculate min, max, average and variance. For this
       purpose, it consumes D and C traces read from stdin.  Note, that
       this doesn't work for logical volumes, as high-level drivers
       don't see the completion of the events (C).

       There are options for binary output and human-readable output to
       files and stdout. Output to a message queue is supported as well.

       There is no need to use blkparse with blkiomon. blkiomon is
       capable of consuming binary output written to stdout by blktrace.

OPTIONS         top

       -I interval
              Set sample interval

       -h file
              Human-readable output file. Use '-' for stdout.

       -b file
              Binary output file. Use '-' for stdout.

       -d file
              Output file for data emitted by low level device driver.

       -D file
              Output file for debugging data. Use '-' for stdout.

       -Q path_name
              Sets path_name as path name for existing message queue to
              be used for binary output.

       -q msg_queue_id
              Sets msg_queue_id as ID for an existing message queue to
              be used for binary output.

       -m msg_id
              Sets msg_id as message identifier to be used for binary
              output messages written to an existing message queue.

              Print program version.

EXAMPLES         top

       To get I/O statistics for /dev/sdw every 10 seconds for a period
       of one hour, use the following command:

           % blktrace /dev/sdw -a issue -a complete -w 3600 -o - |
       blkiomon -I 10 -h -

AUTHORS         top

       blkiomon and this man page were written by Martin Peschke.

REPORTING BUGS         top

       Report bugs to <>

COPYRIGHT         top

       Copyright © 2008 IBM Corp.
       This is free software.  You may redistribute copies of it under
       the terms of the GNU General Public License
       <>.  There is NO WARRANTY, to
       the extent permitted by law.

SEE ALSO         top

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

COLOPHON         top

       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] It is not
       known how to report bugs for this man page; if you know, please
       send a mail to  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

                              July 17, 2008                  BLKIOMON(8)