biotop(8)

💾 biotop(8) — System Manager's Manual 💾

✨ NAME ✨

biotop — Block device (disk) I/O by process top. 💖

🎀 SYNOPSIS 🎀

biotop [-h] [-C] [-r MAXROWS] [-p PID] [interval] [count]

📖 DESCRIPTION 📖

okay so this is top but for disks 💅

It traces block device I/O (disk I/O) and prints a per-process summary every interval (1 second by default). The summary is sorted by the top disk consumers by throughput (Kbytes), so you can see who's really eating the disk. 🔥 The PID and process name shown are measured from when the I/O was first created, which usually identifies the responsible process. 🫶

For efficiency, it uses in-kernel eBPF maps to cache process details (PID and comm) by I/O request, plus a starting timestamp for calculating I/O latency, and the final summary. the way that's so smart 🧚

It works by tracing various kernel blk_*() functions using dynamic tracing, and it will need updating to match any changes to those functions. bestie, keep that in mind 🙈

⚠️ Since this uses BPF, only the root user can use this tool. no cap, you need to be root or it's a hard no 💀

🧰 REQUIREMENTS 🧰

You'll need CONFIG_BPF and bcc. ✨

👑 OPTIONS 👑

• -C — don't clear the screen, keep the old output visible 🌸
• -r MAXROWS — max number of rows to print. default is 20 💜
• -p PID — trace this PID only 🎯
• interval — time between updates, in seconds ⏱️
• count — how many interval summaries you want 🔢

💅 EXAMPLES 💅

Summarize block device I/O by process, with a 1 second screen refresh:

# biotop

Don't clear the screen:

# biotop -C

5 second summaries, 10 times only:

# biotop 5 10

🦋 FIELDS 🦋

• loadavg — the contents of /proc/loadavg 🌈
• PID — cached process ID, if present. this usually (but isn't guaranteed to) identify the responsible process for the I/O 🆔
• COMM — cached process name, if present. this usually (but isn't guaranteed to) identify the responsible process for the I/O 🏷️
• D — direction: R == read, W == write. this is a simplification 🔄
• MAJ — major device number 🔢
• MIN — minor device number 🔢
• DISK — disk device name 💾
• I/O — number of I/O during the interval 📦
• Kbytes — total Kbytes for these I/O during the interval 📈
• AVGms — average time for the I/O (latency) from issue to the device, to its completion, in milliseconds ⚡

🌙 OVERHEAD 🌙

block device I/O usually happens at a relatively low frequency (< 10,000/s), so the overhead for this tool is expected to be low or negligible. ✨ For high IOPS storage systems, though, test and quantify before use. 🙈

🌐 SOURCE 🌐

This is from bcc. 🐝

https://github.com/iovisor/bcc

Also look in the bcc distribution for a companion _examples.txt file containing example usage, output, and commentary for this tool. it's giving helpful 📚

🖥️ OS 🖥️

Linux 🐧

🚧 STABILITY 🚧

Unstable, still in development. 🛠️

🎨 AUTHOR 🎨

Brendan Gregg, Rocky Xing 🫶

💡 INSPIRATION 💡

top(1) by William LeFebvre 🌟

🔗 SEE ALSO 🔗

biosnoop(8), biolatency(8), iostat(1) 💜

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that's a wrap, bestie 🎀 this page is from the USER COMMANDS section, dated 2016-02-06, and it's all about biotop(8) 💖✨