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

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

DESCRIPTION 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 doesnt work for logical vol- umes, as high-level drivers dont 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 -I interval --interval=interval Set sample interval

-h file --human-readable=file Human-readable output file. Use - for stdout.

-b file --binary=file Binary output file. Use - for stdout.

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

-D file --debug=file Output file for debugging data. Use - for stdout.

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

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

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

-V --version Print program version.

EXAMPLES 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 blkiomon and this man page were written by Martin Peschke.

REPORTING BUGS Report bugs to <>

COPYRIGHT 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 btrace (8), blktrace (8), blkparse (1), verify_blkparse (1), blkrawver- ify (1), btt (1)

July 17, 2008 BLKIOMON(8)