BLKIOMON(8)

💅 BLKIOMON(8) — the block device monitor that literally slays

okay bestie, welcome to blkiomon(8), and no I'm not gatekeeping this one 💖 the vibe is simple: it's a block device I/O monitor, it's written by Martin Peschke, and it's here to make your storage stats look iconic. let's get into it ✨

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🦋 SYNOPSIS

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

that's the whole assignment, fr fr — every flag below, no mystery, no cap 🫶

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✨ DESCRIPTION

so blkiomon is a block device I/O monitor. the way it works: 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. chef's kiss 🎀

to do all that, it consumes D and C traces read from stdin. and here's the caveat bestie, listen up 👇

heads up: this doesn't work for logical volumes, because high-level drivers don't see the completion of the events (C). the data just isn't there 😭

there are options for binary output and human-readable output to files and stdout. output to a message queue is supported as well — oh we love a quadfecta 💅

and bestie, plot twist: there is no need to use blkparse with blkiomon. blkiomon is capable of consuming binary output written to stdout by blktrace. we skip the middleman, we ate 🔥

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🌸 OPTIONS

one bullet per flag, and I did not skip a single one. organize me, put me in a list 💜

• -I interval, --interval=interval — set the sample interval. that's your heartbeat, your rhythm, your whole temporal situation ⭐
• -h file, --human-readable=file — human-readable output file. use - for stdout. obsessed 🎀
• -b file, --binary=file — binary output file. use - for stdout. it's giving machine-readable realness 🦋
• -d file, --dump-lldd=file — output file for data emitted by the low level device driver. literally what it says 👑🌈
• -D file, --debug=file — output file for debugging data. use - for stdout. when things get weird, you come here 🙈
• -Q path_name, --msg-queue=path_name — sets path_name as path name for an existing message queue to be used for binary output. message queue era ✨
• -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. it's the queue's whole identity fr fr 💖
• -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. label your messages, bestie 🏷️
• -V, --version — print program version. say hi to the version, it says hi back 👋

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🔥 EXAMPLES

okay so real scenario, bestie: 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 -

look at that pipe. look at that -I 10. look at that -h - sending human-readable straight to stdout. iconic, no notes, ate 💅🥰

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👑 AUTHORS

blkiomon and this man page were written by Martin Peschke. king behavior, we stan 🫶

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💀 REPORTING BUGS

found a bug? don't suffer in silence, bestie. report bugs to <linux-btrace@vger.kernel.org>. the maintainers want to hear about it, that's the whole point 🌈

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🧚 COPYRIGHT

• Copyright © 2008 IBM Corp.
• 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.

read that again bestie: NO WARRANTY, all caps, no ambiguity, no vibes-based exceptions. it's free software but it's not a promise 💜

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🍓 SEE ALSO

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

go read them, they're all in the same friend group ✨ iykyk

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and that's the whole page, bestie 💖 this one's from the July 17, 2008 release, matching this BLKIOMON(8) man page, and we're closing it out with the full group hug — mwah, slay, go monitor some block devices responsibly 🎀🦋💅