bitesize(8)

✨ bitesize(8) — System Manager's Manual ✨

💖 NAME 💖

bitesize — okay so this one summarizes block device I/O size as a histogram. It's a Linux eBPF/bcc tool, so it's giving low-level and I'm obsessed 🔥

🎀 SYNOPSIS 🎀

bitesize

🌸 DESCRIPTION 🌸

Bestie, this shows you the I/O distribution for requested block sizes, sorted by process name 💅

It works by tracing block:block_rq_issue and printing a histogram of I/O size. Literally so clean ✨

🚨 Since this uses BPF, only the root user can use this tool. Sorry bestie, no cap 🙈

🧚 REQUIREMENTS 🧚

You'll need CONFIG_BPF and bcc. Make sure you've got both before you try to run it 🫶

🦋 EXAMPLES 🦋

Count I/O size per process until you hit Ctrl-C:

# bitesize

💜 FIELDS 💜

• Kbtes — the size in kilobytes of the range 📏
• count — how many I/O fell into this range 🔢
• distribution — an ASCII bar chart so you can vibe-check the distribution at a glance (based on the count column) 📊

🔥 OVERHEAD 🔥

Okay so this traces a block I/O tracepoint to update a histogram, and that histogram is asynchronously copied to user-space. It's very efficient, and for most storage I/O rates (< 10k IOPS) the overhead should be negligible 🌈

⚠️ If you're in a higher IOPS storage environment, test and quantify the overhead before use. Don't skip this one, bestie 💀

🍓 SOURCE 🍓

This is from bcc, obviously iconic 👑

https://github.com/iovisor/bcc

Also look in the bcc distribution for a companion _examples.txt file. It has example usage, output, and commentary for this tool, so it's lowkey required reading 📖

🌈 OS 🌈

Linux, periodt 💅

🙈 STABILITY 🙈

Unstable, still in development. Be gentle with it 🥺

🌟 AUTHOR 🌟

Allan McAleavy ✨

💫 SEE ALSO 💫

The lwtools systemtap script that inspired this tool lives at:

https://github.com/brendangregg/systemtap-lwtools/blob/master/disk/bitesize-nd.stp

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Stay iconic, bestie 💖 This page is from the USER COMMANDS section, dated 2016-02-05, and it's all about bitesize(8) 🧚✨